Engine Mechanical - 2.4l Buick LaCrosse II

Fastener Tightening Specifications (LUK)

Fastener Tightening Specifications (LUK)

Engine Mechanical Specifications (LUK)

Engine Mechanical Specifications (LUK)

Adhesives, Fluids, Lubricants, and Sealers

Adhesives, Fluids, Lubricants, and Sealers

Scheme 1

Engine Block- Front View

Scheme 2

Engine Block- Back View

Scheme 3

Engine Block- Right Side View

Scheme 4

Engine Block- Left Side View

Scheme 5

Engine Block- Bottom View

Scheme 6

Engine Block- Top View

Scheme 7

Lower Crankcase- Front View

Scheme 8

Lower Crankcase- Back View

Scheme 9

Lower Crankcase- Bottom View

Scheme 10

Lower Crankcase- Right View

Scheme 11

Lower Crankcase- Left View

Scheme 12

Cylinder Head- Top View

Scheme 13

Cylinder Head- Intake Manifold Deck View

Scheme 14

Cylinder Head- Exhaust Manifold Deck View

Scheme 15

Cylinder Head- Front View

Scheme 16

Cylinder Head- Back View

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Identification can be made through the use of the Broadcast Code label on the engine (1) and the use of the partial VIN etched in one of two places - the primary location is on the starter motor flange (2). The secondary location is the oil filter bowl.

Scheme 23

1. Barcode (1)
2. Sequence Number (2)
3. Day (3)
4. Month (4)
5. Year (5)
6. Engine Assembly Plant (6)
7. Broadcast Code (7)
8. Part Designation (8)
9. Engine Assembly Number (9)
10. Broadcast Code (10)

The partial VIN identifies the specific vehicle by sequence number.

Strategy Based Diagnostics

1. Perform the «Diagnostic System Check - Vehicle»(/buick/lacrosse/ii-2009-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) before using the symptom tables, if applicable.
2. Review the system operations in order to familiarize yourself with the system functions. Refer to «Disassembled Views»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) ,, «Engine Component Description (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) , and «Lubrication Description»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary.

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the engine.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Check for the correct oil level, proper oil viscosity, and correct filter application.
4. Verify the exact operating conditions under which the concern exists. Note factors such as engine RPM, ambient temperature, engine temperature, amount of engine warm-up time, and other specifics.
5. Compare the engine sounds, if applicable, to a known good engine and make sure you are not trying to correct a normal condition.

Intermittent

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Base Engine Misfire without Internal Engine Noises»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__base-engine-misfire-without-internal-engine)
2. «Base Engine Misfire with Abnormal Internal Lower Engine Noises»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__base-engine-misfire-with-abnormal-internal)
3. «Base Engine Misfire with Abnormal Valve Train Noise»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__base-engine-misfire-with-abnormal-valve)
4. «Base Engine Misfire with Coolant Consumption»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__base-engine-misfire-with-coolant-consumption)
5. «Base Engine Misfire with Excessive Oil Consumption»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__base-engine-misfire-with-excessive-oil)
6. «Engine Noise on Start-Up, but Only Lasting a Few Seconds»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-noise-on-start-up-but-only)
7. «Upper Engine Noise, Regardless of Engine Speed»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__upper-engine-noise-regardless-of-engine)
8. «Lower Engine Noise, Regardless of Engine Speed»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__lower-engine-noise-regardless-of-engine)
9. «Engine Noise Under Load»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-noise-under-load)
10. «Engine Will Not Crank - Crankshaft Will Not Rotate»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-will-not-crank-crankshaft)
11. «Engine Compression Test»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-compression-test)
12. «Oil Consumption Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__oil-consumption-diagnosis)
13. «Oil Pressure Diagnosis and Testing»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__oil-pressure-diagnosis-and-testing)
14. «Oil Leak Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__oil-leak-diagnosis)
15. «Drive Belt Chirping, Squeal, and Whine Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l)
16. «Drive Belt Rumbling and Vibration Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l)
17. «Drive Belt Falls Off and Excessive Wear Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l)
18. «Drive Belt Tensioner Diagnosis»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-tensioner-diagnosis)

Base Engine Misfire without Internal Engine Noises

Base Engine Misfire without Internal Engine Noises

Base Engine Misfire with Abnormal Internal Lower Engine Noises

Base Engine Misfire with Abnormal Internal Lower Engine Noises

Base Engine Misfire with Abnormal Valve Train Noise

Base Engine Misfire with Abnormal Valve Train Noise

Base Engine Misfire with Coolant Consumption

Base Engine Misfire with Coolant Consumption

Base Engine Misfire with Excessive Oil Consumption

Base Engine Misfire with Excessive Oil Consumption

Engine Noise on Start-Up, but Only Lasting a Few Seconds

Engine Noise on Start-Up, but Only Lasting a Few Seconds

Upper Engine Noise, Regardless of Engine Speed

Upper Engine Noise, Regardless of Engine Speed

Lower Engine Noise, Regardless of Engine Speed

Lower Engine Noise, Regardless of Engine Speed

Engine Noise Under Load

Engine Noise Under Load

Engine Will Not Crank - Crankshaft Will Not Rotate

Engine Will Not Crank - Crankshaft Will Not Rotate

Coolant in Combustion Chamber

Coolant in Combustion Chamber

Coolant in Engine Oil

Coolant in Engine Oil

Engine Compression Test

1. Charge the battery if the battery is not fully charged.
2. Disable the ignition system.
3. Disable the fuel injection system.
4. Remove all spark plugs.
5. Turn the ignition to the ON position.
6. Depress the accelerator pedal to position the throttle plate wide open.
7. Start with the compression gauge at zero and crank the engine through 4 compression strokes, 4 puffs.
8. Measure the compression for each cylinder. Record the readings.
9. If a cylinder has low compression, inject approximately 15 ml (1 tablespoon) of engine oil into the combustion chamber through the spark plug hole. Measure the compression again and record the reading.
10. The minimum compression in any 1 cylinder should not be less than 70 percent of the highest cylinder. No cylinder should read less than 690 kPa (100 psi). For example, if the highest pressure in any 1 cylinder is 1 035 kPa (150 psi), the lowest allowable pressure for any other cylinder would be 725 kPa (105 psi). (1 035 x 70% = 725) (150 x 70% = 105). Normal - Compression builds up quickly and evenly to the specified compression for each cylinder. Piston Rings Leaking - Compression is low on the first stroke. Compression builds up with the following strokes, but does not reach normal. Compression improves considerably when you add oil. Valves Leaking - Compression is low on the first stroke. Compression usually does not build up on the following strokes. Compression does not improve much when you add oil. If 2 adjacent cylinders have lower than normal compression, and injecting oil into the cylinders does not increase the compression, the cause may be a head gasket leaking between the cylinders.

Cylinder Leakage Test

Special Tools

EN 35667-A Cylinder Head Leakdown Tester

For equivalent regional tools, refer to Special Tools .

Note. A leakage test may be performed in order to measure cylinder/combustion chamber leakage. High leakage may indicate one or more of the following

1. Worn or burnt valves
2. Broken valve springs
3. Stuck valve lash adjusters
4. Incorrect valve lash/adjustment
5. Damaged piston
6. Worn piston rings
7. Worn or scored cylinder bore
8. Damaged cylinder head gasket
9. Cracked or damaged cylinder head
10. Cracked or damaged engine block

1. Disconnect the battery ground negative cable.
2. Remove the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
3. Rotate the crankshaft to place the piston in the cylinder being tested at Top Dead Center (TDC) of the compression stroke.
4. Install the EN 35667-A tester or equivalent.
5. Apply shop air pressure to the EN 35667-A tester and adjust according to the manufacturers instructions.
6. Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions: Air leakage sounds at the throttle body or air inlet hose that may indicate a worn or burnt intake valve or a broken valve spring. Air leakage sounds at the exhaust system tailpipe that may indicate a worn or burnt exhaust valve or a broken valve spring. Air leakage sounds from the crankcase, oil level indicator tube, or oil fill tube that may indicate worn piston rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block or a damaged cylinder head. Air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket.
7. Perform the leakage test on the remaining cylinders and record the values.

Oil Consumption Diagnosis

Excessive oil consumption, not due to leaks, is the use of 0.9 L (1 qt) or greater of engine oil within 3 200 kilometers (2, 000 miles). The causes of excessive oil consumption include the following conditions

1. External oil leaks Tighten bolts and/or replace gaskets and oil seals as necessary.
2. Incorrect oil level or improper reading of oil level indicator With the vehicle on a level surface, allow adequate drain down time and inspect for the correct oil level.
3. Improper oil viscosity Use recommended SAE viscosity for the prevailing temperatures.
4. Continuous high speed driving and/or severe usage
5. Crankcase ventilation system restrictions or malfunctioning components
6. Valve guides and/or valve stem oil seals worn, or the seal omitted Ream guides and install oversize service valves and/or new valve stem oil seals.
7. Piston rings broken, improperly installed, worn, or not seated properly Allow adequate time for rings to seat. Replace broken or worn rings, as necessary.
8. Piston improperly installed or mis-fitted

Oil Pressure Diagnosis and Testing

Special Tools

1. CH-48027 Digital Pressure Gauge
2. EN-21867-850 Oil Pressure Gauge Adapter

For equivalent regional tools, refer to Special Tools .

1. With the vehicle on a level surface, allow adequate drain down time of 2-3 minutes and measure for a low oil level. Add the recommended grade engine oil and fill the crankcase until the oil level measures full on the oil level indicator.
2. Run the engine, and verify low, or no oil pressure on the vehicle gauge or light. Listen for a noisy valve train or a knocking noise.
3. Inspect for the following: Correct oil filter with anti-drain back feature and O-ring on the cylinder block side of the filter Oil diluted by moisture or unburned fuel mixtures Improper oil viscosity for the expected temperature Incorrect or malfunctioning oil pressure sender Incorrect or malfunctioning oil pressure gauge Plugged oil filter Malfunctioning oil bypass valve
4. Remove the oil pressure sender or another engine block oil gallery plug.
5. Install EN-21867-850 adapter and CH-48027 gauge and measure the engine oil pressure.
6. Compare the readings to specifications. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
7. If the engine oil pressure is below specifications, inspect the engine for one or more of the following: Correct oil filter with anti-drain back feature and O-ring on the cylinder block side of the filter Oil pump worn or dirty Refer to «Oil Pump Disassemble»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__oil-pump-disassemble) . Oil pump-to-engine front cover bolts loose Refer to «Engine Front Cover and Oil Pump Installation»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-front-cover-and-oil-pump) . Oil pump screen loose, plugged, or damaged Oil pump screen O-ring seal missing or damaged Malfunctioning oil pump pressure regulator valve Excessive bearing clearance Refer to «Crankshaft and Bearing Cleaning and Inspection»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__crankshaft-and-bearing-cleaning-and-inspection) . Cracked, porous or restricted oil galleries Oil gallery plugs missing or incorrectly installed Refer to «Engine Block Assemble»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-block-assemble) . Broken lash adjusters

Oil Leak Diagnosis

Oil Leak Diagnosis

Crankcase Ventilation System Inspection/Diagnosis (Without Turbocharger)

Special Tools

EN 23951 Valve Manometer

1. Remove the oil level indicator. Install a EN 23951 valve manometer or equivalent.
2. Start the engine.
3. Check for slight vacuum. The vacuum level should be less than 3.377 kPa (1 in Hg).
4. If vacuum is higher, inspect and verify that the clean air hose from cam cover to air intake is not blocked or kinked.
5. If vacuum is in the normal range, block or pinch off the clean air hose. The clean air hose is the hose between the cam cover and air intake system. Vacuum should increase on the manometer. If held too long, vacuum will be drawn through the crankshaft seals creating a sucking sound.
6. If vacuum does not increase, the orifice in the intake manifold could be plugged.
7. If there is zero vacuum or pressure, verify compression of the engine.
8. If compression is normal, check for a blocked orifice at the intake manifold. Clean the orifice.

Diagnostic Aids

1. A chirping or squeal noise may be intermittent due to moisture on the drive belts or the pulleys. It may be necessary to spray a small amount of water on the drive belts in order to duplicate the customers concern. If spraying water on the drive belt duplicates the symptom, cleaning the belt pulleys may be the probable solution.
2. If the noise is intermittent, verify the accessory drive components by varying their loads making sure they are operated to their maximum capacity. An overcharged A/C system, power steering system with a pinched hose or wrong fluid, or a generator failing are suggested items to inspect.
3. A chirping, squeal or whine noise may be caused by a loose or improper installation of a body or suspension component. Other items of the vehicle may also cause the noise.
4. The drive belts will not cause a whine noise.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2 The noise may not be engine related. This step is to verify that the engine is making the noise. If the engine is not making the noise do not proceed further with this table.
2. 3 The noise may be an internal engine noise. Removing the drive belts one at a time and operating the engine for a brief period will verify the noise is related to the drive belt. When removing the drive belt the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belts removed.
3. 4 Inspect all drive belt pulleys for pilling. Pilling is the small balls or pills or it can be strings in the drive belt grooves from the accumulation of rubber dust.
4. 6 Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure for that pulley.
5. 10 Inspecting of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed.
6. 12 Inspecting the pulleys for being bent should include inspecting for a dent or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley.
7. 14 This test is to verify that the drive belt tensioner operates properly. If the drive belt tensioner is not operating properly, proper belt tension may not be achieved to keep the drive belt from slipping which could cause a squeal noise.
8. 15 This test is to verify that the drive belt is not too long, which would prevent the drive belt tensioner from working properly. Also if an incorrect length drive belt was installed, it may not be routed properly and may be turning an accessory drive component in the wrong direction.
9. 16 Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure for that pulley.
10. 17 This test is to verify that the pulleys are the correct diameter or width. Using a known good vehicle compare the pulley sizes.
11. 19 Replacing the drive belt when it is not damaged or there is not excessive pilling will only be a temporary repair.

Drive Belt Chirping, Squeal, and Whine Diagnosis

The accessory drive components can have an affect on engine vibration. Vibration from the engine operating may cause a body component or another part of the vehicle to make rumbling noise. Vibration can be caused by, but not limited to the A/C system over charged, the power steering system restricted or the incorrect fluid, or an extra load on the generator. To help identify an intermittent or an improper condition, vary the loads on the accessory drive components.

The drive belt may have a rumbling condition that can not be seen or felt. Sometimes replacing the drive belt may be the only repair for the symptom.

If replacing the drive belt, completing the diagnostic table, and the noise is only heard when the drive belts are installed, there might be an accessory drive component with a failure. Varying the load on the different accessory drive components may aid in identifying which component is causing the rumbling noise.

The numbers below refer to the step numbers on the diagnostic table.

1. 2 This test is to verify that the symptom is present during diagnosing. Other vehicle components may cause a similar symptom.
2. 3 This test is to verify that one of the drive belts is causing the rumbling noise or vibration. Rumbling noise may be confused with an internal engine noise due to the similarity in the description. Remove only one drive belt at a time if the vehicle has multiple drive belts. When removing the drive belts the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belts removed.
3. 4 Inspecting the drive belts is to ensure that they are not causing the noise. Small cracks across the ribs of the drive belt will not cause the noise. Belt separation is identified by the plys of the belt separating and may be seen at the edge of the belt our felt as a lump in the belt.
4. 5 Small amounts of pilling is normal condition and acceptable. When the pilling is severe the drive belt does not have a smooth surface for proper operation.
5. 9 Inspecting of the fasteners can eliminate the possibility that the wrong bolt, nut, spacer, or washer was installed.
6. 11 This step should only be performed if the water pump is driven by the drive belt. Inspect the water pump shaft for being bent. Also inspect the water pump bearings for smooth operation and excessive play. Compare the water pump with a known good water pump.
7. 12 Accessory drive component brackets that are bent, cracked, or loose may put extra strain on that accessory component causing it to vibrate.

Drive Belt Rumbling and Vibration Diagnosis

If the drive belt repeatedly falls off the drive belt pulleys, this is because of pulley misalignment.

An extra load that is quickly applied on released by an accessory drive component may cause the drive belt to fall off the pulleys. Verify the accessory drive components operate properly.

If the drive belt is the incorrect length, the drive belt tensioner may not keep the proper tension on the drive belt.

Excessive wear on a drive belt is usually caused by an incorrect installation or the wrong drive belt for the application.

Minor misalignment of the drive belt pulleys will not cause excessive wear, but will probably cause the drive belt to make a noise or to fall off.

Excessive misalignment of the drive belt pulleys will cause excessive wear but may also make the drive belt fall off.

The numbers below refer to the step numbers on the diagnostic table.

1. 2 This inspection is to verify the condition of the drive belt. Damage may of occurred to the drive belt when the drive belt fell off. The drive belt may of been damaged, which caused the drive belt to fall off. Inspect the belt for cuts, tears, sections of ribs missing, or damaged belt plys.
2. 4 Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across 2 or 3 pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure of that pulley.
3. 5 Inspecting the pulleys for being bent should include inspecting for a dent or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley.
4. 6 Accessory drive component brackets that are bent or cracked will let the drive belt fall off.
5. 7 Inspecting of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed. Missing. loose, or the wrong fasteners may cause pulley misalignment from the bracket moving under load. Over tightening of the fasteners may cause misalignment of the accessory component bracket.
6. 13 The inspection is to verify the drive belt is correctly installed on all of the drive belt pulleys. Wear on the drive belt may be caused by mis-positioning the drive belt by one groove on a pulley.
7. 14 The installation of a drive belt that is too wide or too narrow will cause wear on the drive belt. The drive belt ribs should match all of the grooves on all of the pulleys.
8. 15 This inspection is to verify the drive belt is not contacting any parts of the engine or body while the engine is operating. There should be sufficient clearance when the drive belt accessory drive components load varies. The drive belt should not come in contact with an engine or a body component when snapping the throttle.

Drive Belt Falls Off and Excessive Wear Diagnosis

Drive Belt Tensioner Diagnosis

Drive Belt Tensioner Diagnosis

Scheme 24

Intake Manifold Cover Replacement

Drive Belt Replacement

Special Tools

EN-48932 Hydraulic Belt Tensioner Compressor

For equivalent regional tools, refer to Special Tools .

Removal Procedure

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Remove the tensioner stop fastener (1) and stop (2).
3. Install the EN-48932 compressor (1) to the drive belt tensioner spring.
4. Compress the drive belt tensioner spring fully using the EN-48932 compressor.
5. Reposition the idler pulley (2) to release tension off the drive belt.
6. Remove the drive belt from under the middle idler pulley.
7. Remove the drive belt from the vehicle.

Installation Procedure

1. With the EN-48932 compressor still compressing the tensioner spring Install and position the drive belt around all of the pulleys except for the middle idler pulley.
2. Rotate pulley (2) clockwise and install the drive belt under the middle idler pulley.
3. Ensure the drive belt tensioner idler pulley is fully seated against the drive belt.
4. Loosen the forcing bolt on the EN-48932 compressor (1) and remove from the drive belt tensioner spring.
5. Ensure that the drive belt tensioner idler is fully seated against the drive belt.
6. Install the tension stop (2) and fastener (1), then tighten to 10 N.m (89 lb in).
7. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

Drive Belt Tensioner Replacement

Special Tools

J-45025 Torque Wrench Adapter

For equivalent regional tools, refer to Special Tools .

1. Remove the drive belt. Refer to «Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement) .
2. Remove the right side engine mount. Refer to «Engine Mount Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
3. Remove the drive belt tensioner bolts (2, 3).
4. Remove the drive belt tensioner (1) with drive belt tensioner bolt (3) from top of vehicle.

1. Install the lower tensioner pivot bolt (2) into the tensioner (1).
2. Position the tensioner assembly in place.
3. Install the drive belt tensioner bolts (2, 3).
4. Tighten the bolts (2, 3) in sequence. Make sure that the torque wrench and J-45025 are in a straight line to ensure proper torque at the bolt. Tighten the top bolt to 22 N.m (16 lb ft). Use the J-45025 adapter, to tighten the tensioner pivot bolt to 42 N.m (31 lb ft).
5. Install the drive belt. Refer to «Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement) .
6. Install the right side engine mount. Refer to «Engine Mount Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Scheme 25

Engine Oil Pressure Switch Replacement

Engine Mount Inspection

1. Install the engine support fixture. Refer to «Engine Support Fixture»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-support-fixture) .
2. Raise the engine slightly and observe the engine mount. Raising the engine removes the weight from the engine mount and creates a slight tension on the rubber portion.
3. Replace the engine mount if the engine mount exhibits any of the following conditions: The hard rubber is covered with heat check cracks. The rubber is separated from the metal plate of the engine mount. The rubber is split through the center of the engine mount. The engine mount itself is leaking fluid.
4. For engine mount replacement. Refer to «Engine Mount Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Scheme 26

Engine Mount Bracket Replacement

Powertrain Mount Balancing

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Remove the battery tray. Refer to «Battery Tray Replacement»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid) .
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
4. Loosen the front transaxle mount through bolt (1).
5. Loosen the rear transaxle mount through bolt (1).
6. Lower the vehicle.
7. Position two floor jacks with wood blocks under the engine and transaxle in order to support the powertrain assembly.
8. Loosen the transaxle mount bolts (1).
9. Loosen the engine mount to bracket bolts (1).
10. Reposition both floor jacks in order to allow a 1/8 inch gap between the mount and bracket.
11. Tighten the transaxle mount bolts (1) in the following sequence. Rear Front Middle Tighten Tighten the bolts to 45 N.m (33 lb ft).
12. Tighten the engine mount to bracket bolts (1) in the following sequence. Rear Front Tighten Tighten the bolts to 50 N.m (37 lb ft).
13. Remove the floor jacks from under the oil pan.
14. Shake the powertrain vigorously from front to rear and allow the powertrain to settle.
15. Raise the vehicle.
16. Tighten the rear transaxle mount through bolt (1). Tighten Tighten the bolt to 100 N.m (74 lb ft).
17. Tighten the front transaxle mount through bolt (1). Tighten Tighten the bolt to 100 N.m (74 lb ft).
18. Lower the vehicle.
19. Install the battery tray. Refer to «Battery Tray Replacement»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid) .
20. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

Powertrain Mount Balancing - Lower

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
2. Loosen the front transaxle mount through bolt.
3. Loosen the rear transaxle mount through bolt.
4. Shake the powertrain vigorously from front to rear and allow the powertrain to settle.
5. Tighten the rear transaxle mount through bolt to 100 N.m (74 lb ft).
6. Tighten the front transaxle mount through bolt to 100 N.m (74 lb ft).
7. Lower the vehicle.

Scheme 27

Engine Mount Replacement

Engine Support Fixture

Special Tools

1. EN-28467-B Universal Engine Support Fixture
2. EN-28467-500B Engine Support Fixture
3. EN-43405-10 Engine Support Fixture Adaptor

For equivalent regional tools, refer to Special Tools .

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Assemble the EN-28467-B universal engine support fixture to the EN-43405-1 engine support feet (passenger side) and EN-43405-2 engine support feet (drivers side) (1) and place across the engine compartment.
3. From the EN-28467-500B universal engine support fixture, install the radiator shelf tube J-28467-2A (1) on top of the strut tower tube J-28467-3 (2) above the engine front (right back) lift hook bracket.
4. Install the round tube of the front support assembly J-28467-4A (3) through the large hole in the radiator shelf tube J-28467-2A.
5. Locate the J-28467-4A front support assembly to the upper tie bar.
6. Install the J-28467-9 7/16 inch x 2.0 inch quick-release pin (4) through the top hole in the J-28467-4A front support assembly.
7. Install the J-28467-1A cross bracket assembly (1).
8. Hand tighten the J-28467-1A cross bracket wing nuts (2).
9. Install the J-28467-7A bolt hook through the J-28467-6A bracket.
10. Install the J-28467-34 lift hook wing nut and washer to the J-28467-7A lift hook.
11. Repeat the previous 2 steps in order to assemble 2 lift hooks and brackets.
12. Install one of the lift hook and bracket assemblies (1) to the engine support fixture long bar (2).
13. Install the other lift hook and bracket assembly (3) to the J-28467-2A radiator shelf tube (4) above the engine front lift bracket.
14. Install the lift hook J-28467-7A through the engine rear lift bracket (2).
15. Install the lift hook J-28467-7A through the engine front lift bracket.
16. Hand tighten the lift hook wing nuts J-28467-34 in order to remove all slack from the engine support fixture assembly.

1. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Remove the oil level indicator.
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
4. Remove the engine wiring harness clip (1) from the oil level indicator tube bracket (2).
5. Remove the knock sensor electrical connector lead (1) from the oil level indicator tube bracket (2).
6. Lower the vehicle.
7. Remove the oil level indicator tube bolt.
8. Remove the oil level indicator tube.
9. Remove the oil level indicator tube O-ring seals, if necessary.

1. Install NEW oil level indicator tube O-ring seals, if necessary.
2. Install the oil level indicator tube.
3. Install the oil level indicator tube bolt and tighten to 10 N.m (89 lb in).
4. Raise and support the vehicle.
5. Install the knock sensor electrical connector lead (1) to the oil level indicator tube bracket (2).
6. Install the engine wiring harness clip (1) to the oil level indicator tube bracket (2).
7. Lower the vehicle.
8. Install the engine wiring harness clip (1) to the oil level indicator tube bracket (2).
9. Install the oil level indicator.
10. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

Scheme 28

Positive Crankcase Ventilation Hose/Pipe/Tube Replacement

1. Remove the air cleaner outlet duct (2). Refer to «Air Cleaner Outlet Duct Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Remove the intake manifold cover (2). Refer to «Intake Manifold Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l)
3. Reposition the hose clamp (1) and disconnect the radiator inlet hose (2). Refer to «Radiator Inlet Hose Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Remove the starter generator. Refer to «Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
5. Disconnect the fuel injector wiring harness electrical connector (3) from the engine wiring harness electrical connector.
6. Remove the fuel injector wiring harness fastener (4) from the intake manifold.
7. Disconnect the evaporative emission (EVAP) canister purge tube (1) from the intake manifold. Refer to «Plastic Collar Quick Connect Fitting Service»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
8. Disconnect the MAP sensor connector (2).
9. Disconnect the fuel pump electrical connector (1).
10. Disconnect the engine wiring harness electrical connector (2) from the throttle actuator control (TAC).
11. Reposition the vacuum brake booster hose clamp (3) at the intake manifold.
12. Remove the vacuum brake booster hose (4) from the intake manifold.
13. Reposition the engine harness (5) away from the intake manifold.
14. Remove the throttle body (2). Refer to «Throttle Body Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
15. Remove the fastener (3) from the oil level indicator tube and remove the tube. Refer to «Oil Level Indicator Tube Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
16. Remove the fuel feed pipe (2). Refer to «Fuel Feed Pipe Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
17. Remove the fuel pump cover (1-4). Refer to «Fuel Pump Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
18. Remove the intake manifold heat shield (1).
19. Remove the intake manifold lower bolts (1).
20. Remove the intake manifold upper nuts (2).
21. Remove the intake manifold (3).
22. Remove and inspect the intake manifold gasket.

1. Install a NEW intake manifold gasket if necessary, otherwise install the old gasket.
2. Install the intake manifold (3).
3. Install the intake manifold upper nuts (2).
4. Install the intake manifold lower bolts (1). Tighten the bolts/nuts (1 and 2) to 10 N.m (89 lb in).
5. Install the intake manifold heat shield (1).
6. Install the fuel pump cover (1-4). Refer to «Fuel Pump Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
7. Install the fuel feed pipe (2). Refer to «Fuel Feed Pipe Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
8. Install the throttle body (2). Refer to «Throttle Body Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
9. Remove the oil level indicator tube. Refer to «Oil Level Indicator Tube Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
10. Reposition the engine harness (5) across the intake manifold.
11. Connect the engine wiring harness electrical connector (2) to the throttle actuator control (TAC).
12. Connect the vacuum brake booster hose (4) at the intake manifold.
13. Install the brake booster hose clamp (3).
14. Connect the fuel pump electrical connector (1).
15. Connect the fuel injector wiring harness electrical connector (3) to the engine wiring harness electrical connector.
16. Install the fuel injector wiring harness fastener (4) to the intake manifold.
17. Connect the evaporative emission (EVAP) canister purge tube (1) to the intake manifold. Refer to «Plastic Collar Quick Connect Fitting Service»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
18. Connect the MAP sensor connector (2).
19. Install the starter generator. Refer to «Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
20. Connect the radiator inlet hose (2), reposition the hose clamp (1). Refer to «Radiator Inlet Hose Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
21. Install the intake manifold cover (2). Refer to «Intake Manifold Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l)
22. Install the air cleaner outlet duct (2). Refer to «Air Cleaner Outlet Duct Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

Special Tools

1. EN-45059 Angle Meter
2. EN-38122-A Harmonic Balancer Holder

For equivalent regional tools, refer to Special Tools .

1. Remove the drive belt. Refer to «Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement) .
2. Use EN-38122-A holder (1) to prevent the crankshaft from rotating while loosening the crankshaft balancer bolt (2).
3. Remove and discard the crankshaft balancer bolt.
4. Remove the bolt (1), washer (2), and crankshaft balancer (3).

1. Position the crankshaft balancer (3).
2. Install washer (2) and a NEW crankshaft balancer bolt (1).
3. Use the EN-38122-A holder (1) to hold the crankshaft balancer in order to prevent the balancer from rotating while tightening the bolt (2).
4. Tighten the crankshaft balancer bolt to 100 N.m (74 lb ft) plus an additional 125 degrees using the EN-45059 meter.
5. Install the drive belt. Refer to «Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement) .

Crankshaft Front Oil Seal Replacement

Special Tools

J 35268-A Camshaft/Front Main Seal Installer

1. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
2. Use a flat-bladed tool to remove the seal from the front cover.

1. Use the J 35268-A Camshaft/Front Main Seal Installer in order to install the crankshaft front oil seal to the engine front cover.
2. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

1. J 38122-A Harmonic Balancer Holder
2. J 45059 Angle Meter

For equivalent regional tools, refer to Special Tools .

1. Remove the air cleaner assembly (1). Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Remove the drive belt (1). Refer to «Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement) .
3. Remove the wheelhouse splash shield. Refer to «Front Compartment Splash Shield Replacement»(/buick/lacrosse/ii-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
4. Disconnect and reposition the vacuum booster rear pipe (2). Refer to «Power Brake Booster Vacuum Rear Pipe Replacement (2.4L)»(/buick/lacrosse/ii-2009-2013/remont/mechanical-hydraulic/#hydraulic-brake-system)
5. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
6. Remove the engine front cover bolts.
7. Remove the engine front cover to water pump bolt.
8. Remove the engine front cover.
9. Remove and discard the engine front cover gasket.

1. Install a NEW engine front cover gasket to the dowel pins.
2. Install the engine front cover and install the water pump bolt and tighten to 25 N.m (18 lb ft).
3. Install the engine front cover bolts and tighten to 25 N.m (18 lb ft).
4. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
5. Reposition and connect the vacuum booster rear pipe (2). Refer to «Power Brake Booster Vacuum Rear Pipe Replacement (2.4L)»(/buick/lacrosse/ii-2009-2013/remont/mechanical-hydraulic/#hydraulic-brake-system) .
6. Install the wheelhouse splash shield. Refer to «Front Compartment Splash Shield Replacement»(/buick/lacrosse/ii-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
7. Install the drive belt (1). Refer to «Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement) .
8. Install the air cleaner assembly (1). Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

1. EN-45027 Tensioner Tool
2. EN-45059 Angle Meter
3. EN-48953 Camshaft Actuator Locking Tool

For equivalent regional tools, refer to Special Tools .

1. Remove the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
2. Remove the number 1 cylinder spark plug. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
3. Rotate the crankshaft in the engine rotational direction clockwise, until the number 1 piston is at top dead center (TDC) on the exhaust stroke.
4. Remove the engine front cover. Refer to «Engine Front Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l)
5. Remove the upper timing chain guide bolts and guide.
6. Remove the timing chain tensioner.
7. Install a 24 mm wrench on the hex on the exhaust camshaft in order to hold the camshaft.
8. Remove and discard the exhaust camshaft actuator bolt (2).
9. Remove the exhaust camshaft actuator (1, 3) from the camshaft and timing chain.
10. Remove the timing chain tensioner guide bolt and guide.
11. Remove the fixed timing chain guide access plug.
12. Remove the fixed timing chain guide bolts and guide.
13. Install a 24 mm wrench on the hex on the intake camshaft in order to hold the camshaft.
14. Remove and discard the intake camshaft actuator bolt (2).
15. Remove the intake camshaft actuator (3), and the timing chain through the top of the cylinder head.
16. Remove the outer friction washer (1) if equipped.
17. Ensure the crankshaft gear timing mark (2) is in the 5 o'clock position and crankshaft key is in the 12 o'clock position.
18. Remove the crankshaft sprocket (3).
19. Remove the inner friction washer (1).

1. Ensure the intake camshaft notch is in the 5 o'clock position (2) and the exhaust camshaft notch is in the 7 o'clock position (1). The number 1 piston should be at top dead center (TDC), crankshaft key at 12 o'clock.
2. Ensure the intake camshaft notch is in the 10 o'clock position (2) and the exhaust camshaft notch is in the 7 o'clock position (1). The number 1 piston should be at top dead center (TDC), crankshaft key at 12 o'clock.
3. Install the inner friction washer (1).
4. Install the crankshaft sprocket with the timing mark (2) is in the 5 o'clock position and facing outward.
5. Install the outer friction washer (1) if equipped.
6. Assemble the intake camshaft actuator into the timing chain with the timing mark lined up with the uniquely colored link (1).
7. Lower the timing chain through the opening in the cylinder head. Use care to ensure that the chain goes around both sides of the cylinder block bosses (1, 2).
8. Install the intake camshaft actuator onto the intake camshaft while aligning the dowel pin into the camshaft slot.
9. Hand tighten the new intake camshaft actuator bolt.
10. Route the timing chain around the crankshaft sprocket and line up the first matching colored link (1) with the timing mark on the crankshaft sprocket, in approximately the 5 o'clock position.
11. Install the friction washer, if applicable.
12. Rotate the crankshaft clockwise to remove all chain slack. Do not rotate the intake camshaft.
13. Install the adjustable timing chain guide (2) down through the opening in the cylinder head and install the adjustable timing chain bolt (1). Tighten the adjustable timing chain guide bolt to 10 N.m (89 lb in).
14. Install the exhaust camshaft actuator (2) into the timing chain with the timing mark lined up with the second matching colored link.
15. Install the exhaust camshaft actuator onto the exhaust camshaft, aligning the dowel pin into the camshaft slot.
16. Use 24 mm open ended wrench, rotate the exhaust camshaft approximately 45 degrees until the dowel pin in the camshaft actuator goes into the camshaft slot.
17. When the actuator seats on the cam, tighten the new exhaust camshaft actuator bolt hand tight.
18. Verify that all of the colored links and the appropriate timing marks are still aligned. If they are not aligned, repeat the portion of the procedure necessary to align the timing marks.
19. Install the fixed timing chain guide and bolts. Tighten the fixed timing chain guide bolts to 10 N.m (89 lb in).
20. Install the upper timing chain guide and bolts. Tighten the upper timing chain guide bolts to 10 N.m (89 lb in).
21. Reset the timing chain tensioner by performing the following steps: Remove the snap ring. Remove the piston assembly from the body of the timing chain tensioner. Remove the sealing collar from the piston assembly. Install the EN-45027-2 tool (2) into a vise. Install the notch end of the piston assembly into the EN-45027-2 tool (2). Using the EN-45027-1 tool (1), turn the ratchet cylinder into the piston. Reinstall the sealing collar to the piston assembly. Reinstall the piston assembly into the body of the tensioner. Install the snap ring.
22. Inspect the timing chain tensioner seal for damage. If damaged, replace the seal.
23. Inspect to ensure all dirt and debris is removed from the timing chain tensioner threaded hole in the cylinder head.
24. Install the timing chain tensioner assembly. Tighten the timing chain tensioner to 75 N.m (55 lb ft).
25. The timing chain tensioner is released by compressing it 2 mm (0.079 in), which will release the locking mechanism in the ratchet. To release the timing chain tensioner, use a suitable tool with a rubber tip on the end. Feed the tool down through the cam drive chest to rest on the cam chain. Then give a sharp jolt diagonally downwards to release the tensioner.
26. Install EN-48953 locking tool (1) and tighten the bolts into the cylinder head to 10 N.m (89 lb in).
27. Using a torque wrench, tighten the camshaft actuator bolt to 30 N.m (22 lb ft) plus 100 degrees using the EN-45059 meter.
28. Remove the EN-48953 locking tool.
29. Install the timing chain oiling nozzle (2). Tighten the timing chain oiling nozzle (1) bolt to 10 N.m (89 lb in).
30. Apply sealant compound to the thread of the timing chain guide bolt access hole plug. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
31. Install the timing chain guide bolt access hole plug. Tighten the access hole plug to 90 N.m (66 lb ft).
32. Install the engine front cover. Refer to «Engine Front Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
33. Install the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
34. Install the number 1 cylinder spark plug. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

1. Remove the camshaft timing chain, sprocket, and tensioner. Refer to «Camshaft Timing Chain, Sprocket, and Tensioner Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
2. Remove the adjustable balance shaft chain guide bolt and guide
3. Remove the small balance shaft drive chain guide bolts and guide.
4. Remove the upper balance shaft drive chain guide bolts and guide.
5. Remove the balance shaft drive chain (7).
6. Remove the balance shaft drive sprocket.

1. Install the balance shaft drive sprocket (3).
2. Install the balance shaft drive chain (7) with the colored link lined up with the marks on the balance shaft sprockets and the balance shaft drive sprocket. There are 3 colored links on the chain. Two are chrome and one is copper. Use the following steps in order to line up the links with the sprockets. Place the copper link (5) so that it lines up with the timing mark (2) on the intake side balance shaft sprocket. Working clockwise around the chain, place the chrome link (4) in line with the timing mark (3) on the balance shaft drive sprocket (approximately 6 o'clock position on the sprocket). Place the chain (7) on the water pump drive sprocket. The alignment is not critical. Align the last chrome link (6) with the timing mark (1) on the exhaust side balance shaft drive sprocket.
3. Install the upper balance shaft drive chain guide and bolts and tighten to 12 N.m (106 lb in).
4. Install the small balance shaft drive chain guide and bolts and tighten to 12 N.m (106 lb in).
5. Install the adjustable balance shaft chain guide and bolt and tighten to 10 N.m (89 lb in).
6. Reset the timing chain tensioner by performing the following steps: Rotate the tensioner plunger 90 degrees in its bore and compress the plunger. Rotate the tensioner back to the original 12 o'clock position and insert a paper clip through the hole in the plunger body and into the hose in the tensioner plunger.
7. Install the balance shaft drive chain tensioner and bolts and tighten to 10 N•m (89 lb in).
8. Remove the paper clip from the balance shaft drive chain tensioner.
9. Install the camshaft timing chain, sprocket, and tensioner. Refer to «Camshaft Timing Chain, Sprocket, and Tensioner Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Scheme 29

Camshaft Cover Replacement

Timing Chain Tensioner Replacement

Special Tools

EN-45027 Tensioner Tool.

For equivalent regional tools. Refer to Special Tools .

1. Remove the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
2. Remove the timing chain tensioner.
3. Remove the seal from the tensioner.

1. Inspect the timing chain tensioner. If the timing chain tensioner, O-ring seal, or washer is damaged, replace the timing chain tensioner or O-ring seal as applicable.
2. Measure the timing chain tensioner assembly from end to end. If the timing chain tensioner is to be replaced, a new tensioner should be supplied in the fully compressed non-active state. A tensioner in the compressed state will measure 72 mm (2.83 in) (a) from end to end. A tensioner in the active state will measure 85 mm (3.35 in) (a) from end to end.
3. If the timing chain tensioner is not in the compressed state, perform the following steps: Remove the piston assembly from the body of the timing chain tensioner by pulling it out. Install the EN 45027-2 (2) into a vise. Install the notch end of the piston assembly into the J 45027-2 (2). Using the EN 45027-1 (1), turn the ratchet cylinder into the piston.
4. Inspect the bore of the tensioner body for dirt, debris, and damage. If any damage appears, replace the tensioner. Clean dirt or debris out with a lint-free cloth.
5. Install the compressed piston assembly back into the timing chain tensioner body until it stops at the bottom of the bore. Do not compress the piston assembly against the bottom of the bore. If the piston assembly is compressed against the bottom of the bore, it will activate the tensioner, which will then need to be reset again.
6. At this point the tensioner should measure approximately 72 mm (2.83 in) (a) from end to end. If the tensioner does not read 72 mm (2.83 in) (a) from end to end, repeat steps 3-5.
7. Inspect to ensure all dirt and debris is removed from the timing chain tensioner threaded hole in the cylinder head.
8. Install the timing chain tensioner assembly. Tighten the timing chain tensioner to 75 N.m (55 lb ft).
9. The timing chain tensioner is released by compressing the tensioner 2 mm (0.079 in) which will release the locking mechanism in the ratchet. To release the timing chain tensioner, use a suitable tool with a rubber tip on the end. Feed the tool down through the cam drive chest to rest on the cam chain. Then give a sharp jolt diagonally downwards to release the tensioner.
10. Install the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

1. EN-45059 Angle Meter
2. EN-48749 Timing Chain Retention Tool Kit
3. EN-48953 Camshaft Actuator Locking Tool

For equivalent regional tools, refer to Special Tools .

1. Remove the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
2. Remove the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
3. Rotate the crankshaft clockwise and install the EN-48953 retention tool (1).
4. Install the camshaft actuator retainer bolts and tighten to 10 N.m (89 lb in).
5. Loosen, but DO NOT remove the intake camshaft actuator bolt.
6. Remove the EN-48953 locking tool (1).
7. Clean the timing chain and gears with solvent.
8. Mark the intake and exhaust camshaft actuators and the respective locations on the timing chain.
9. Remove the upper timing chain guide bolts and guide.
10. Remove the timing chain tensioner.
11. Install the EN-48749 retention tool (1) to the intake side of the timing chain.
12. Install the EN-48749 retention tool (1) to the exhaust side of the timing chain.
13. Remove and discard the intake camshaft actuator bolt (1).
14. Rotate the exhaust camshaft clockwise slightly to take the tension off of the timing chain on the intake actuator.
15. Remove the intake camshaft actuator (3) from the camshaft while also removing the actuator from the timing chain.

1. Install the timing chain onto the intake camshaft actuator.
2. Align the intake camshaft actuator alignment mark made previously with the timing chain mark and install the actuator onto the camshaft rotating the exhaust camshaft clockwise, if required.
3. Install a NEW intake camshaft actuator bolt (1) until snug.
4. Remove the timing chain retention tool (1) from the intake side of the timing chain.
5. Remove the timing chain retention tool (1) from the exhaust side of the timing chain.
6. Reset and install the timing chain tensioner. Refer to «Timing Chain Tensioner Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__timing-chain-tensioner-replacement) .
7. Install the EN-48953 retention tool (1).
8. Install the camshaft actuator retainer bolts and tighten to 10 N.m (89 lb in).
9. Tighten the NEW camshaft actuator bolt to 30 N.m (22 lb ft) plus an additional 100 degrees using the EN-45059 meter.
10. To release the tensioner apply a counterclockwise rotational torque to the crankshaft balancer bolt of 45 N.m (33 lb ft).
11. Remove the EN-48953 retention tool (1).
12. Install the upper timing chain guide and bolts and tighten to 10 N.m (89 lb in).
13. Install the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
14. Install the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

1. Remove the exhaust camshaft position actuator. Refer to «Camshaft Position Exhaust Actuator Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__camshaft-position-exhaust-actuator-replacement) .
2. Remove the exhaust camshaft position actuator solenoid valve bolt (1) and valve (2).
3. Mark camshaft caps to ensure they are installed in the same position.
4. Remove the exhaust camshaft cap bolts.
5. Remove the camshaft caps ensuring they are marked and refitted in same position on assembly.
6. Remove the exhaust camshaft.
7. Remove the exhaust camshaft roller finger followers.
8. Remove the hydraulic lash adjusters.

1. Install the hydraulic lash adjusters into their bores in the cylinder head and lubricate. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
2. Lubricate the valve tips. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
3. Position the roller followers on the tip of the valve stem and on the lash adjuster and lubricate. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
4. When installing the camshafts, ensure the intake camshaft notch is in the 10 o'clock position (2) and the exhaust camshaft notch is in the 7 o'clock position (1). The number 1 piston should be at top dead center (TDC), crankshaft key at 12 o'clock.
5. Set the exhaust camshaft on top of the roller followers in the camshaft bearing journals and lubricate. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
6. Rotate the oil seal in the groove of the number one camshaft journal so the split line (1) is at approximately the 12:00 position before installing the camshaft caps.
7. Install the exhaust camshaft with the notch on the front (1) at approximately the 7 o'clock position.
8. Install the camshaft caps and hand start the camshaft cap bolts.
9. Tighten the camshaft cap bolts in increments of 3 turns until they are seated. Tighten the camshaft caps to 10 N.m (89 lb in).
10. Install the exhaust camshaft position actuator solenoid valve (2). Tighten the solenoid valve bolt (1) to 10 N.m (89 lb in).
11. Install the exhaust camshaft position actuator. Refer to «Camshaft Position Exhaust Actuator Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__camshaft-position-exhaust-actuator-replacement) .

Camshaft Position Intake Actuator Replacement

Special Tools

1. EN-45059 Angle Meter
2. EN-48749 Timing Chain Retention Tool Kit
3. EN-48953 Camshaft Actuator Locking Tool

For equivalent regional tools, refer to Special Tools .

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Remove the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
3. Remove the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
4. Rotate the crankshaft clockwise and install the EN-48953 retention tool (1).
5. Install the camshaft actuator retainer bolts and tighten to 10 N.m (89 lb in).
6. Loosen, but DO NOT remove the intake camshaft actuator bolt.
7. Remove the EN-48953 locking tool (1).
8. Clean the timing chain and gears with solvent.
9. Mark the intake and exhaust camshaft actuators and the respective locations on the timing chain.
10. Remove the upper timing chain guide bolts and guide.
11. Remove the timing chain tensioner.
12. Install the EN-48749 retention tool (1) to the intake side of the timing chain.
13. Install the EN-48749 retention tool (1) to the exhaust side of the timing chain.
14. Remove and discard the intake camshaft actuator bolt (1).
15. Rotate the exhaust camshaft clockwise slightly to take the tension off of the timing chain on the intake actuator.
16. Remove the intake camshaft actuator (3) from the camshaft while also removing the actuator from the timing chain.

1. Install the timing chain onto the intake camshaft actuator.
2. Align the intake camshaft actuator alignment mark made previously with the timing chain mark and install the actuator onto the camshaft rotating the exhaust camshaft clockwise, if required.
3. Install a NEW intake camshaft actuator bolt (1) until snug.
4. Remove the timing chain retention tool (1) from the intake side of the timing chain.
5. Remove the timing chain retention tool (1) from the exhaust side of the timing chain.
6. Reset and install the timing chain tensioner. Refer to «Timing Chain Tensioner Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__timing-chain-tensioner-replacement) .
7. Install the EN-48953 retention tool (1).
8. Install the camshaft actuator retainer bolts and tighten to 10 N.m (89 lb in).
9. Tighten the NEW camshaft actuator bolt to 30 N.m (22 lb ft) plus an additional 100 degreesusing the EN-45059 meter.
10. To release the tensioner apply a counterclockwise rotational torque to the crankshaft balancer bolt of 45 N.m (33 lb ft).
11. Remove the EN-48953 retention tool (1).
12. Install the upper timing chain guide and bolts and tighten to 10 N.m (89 lb in).
13. Install the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
14. Install the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
15. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

Camshaft Position Exhaust Actuator Replacement

Special Tools

1. EN-45059 Angle Meter
2. EN-48749 Timing Chain Retention Tool Kit
3. EN-48953 Camshaft Actuator Locking Tool

For equivalent regional tools, refer to Special Tools .

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Remove the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
3. Remove the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
4. Rotate the crankshaft clockwise and install the EN-48953 locking tool (1).
5. Install the camshaft actuator retainer bolts and tighten to 10 N.m (89 lb in).
6. Loosen, but do not remove the exhaust camshaft actuator bolt.
7. Remove the EN-48953 locking tool (1).
8. Clean the timing chain and gears with solvent.
9. Mark the intake and exhaust camshaft actuators and the respective locations on the timing chain.
10. Remove the upper timing chain guide bolts and guide.
11. Remove the timing chain tensioner.
12. Install the EN-48749 retention tool (1) to the exhaust side of the timing chain.
13. Remove and discard the exhaust camshaft actuator bolt (2).
14. Remove the exhaust camshaft actuator (3) from the camshaft while also removing the actuator from the timing chain.

1. Install the timing chain onto the exhaust camshaft actuator.
2. Align the exhaust camshaft actuator alignment mark made previously with the timing chain mark and install the actuator onto the camshaft.
3. Install a NEW exhaust camshaft actuator bolt (2) until snug.
4. Remove the EN-48749 retention tool (1) from the exhaust side of the timing chain.
5. Reset and install the timing chain tensioner. Refer to «Timing Chain Tensioner Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__timing-chain-tensioner-replacement) .
6. Install the EN-48953 locking tool (1).
7. Install the camshaft actuator retainer bolts and tighten 10 N.m (89 lb in).
8. Tighten the NEW camshaft actuator bolt to 30 N.m (22 lb ft) plus an additional 100 degrees using the EN-45059 meter.
9. To release the tensioner apply a counterclockwise rotational torque to the crankshaft balancer bolt of 45 N.m (33 lb ft).
10. Remove the camshaft actuator retainer EN-48953 locking tool (1).
11. Install the upper timing chain guide and bolts and tighten to 10 N.m (89 lb in).
12. Install the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
13. Install the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
14. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .

Valve Stem Oil Seal and Valve Spring Replacement

Special Tools

1. EN-36017 Valve Guide Seal Remover
2. EN-43649 Valve Spring Compressor
3. EN-43649-10 Valve Spring Compressor Adaptor Set
4. EN-43653 Flywheel Holding Tool

For equivalent regional tools refer to Special Tools .

Note. Prevent the crankshaft from rotating clockwise or counterclockwise before using compressed air in the cylinder. Rotation of the crankshaft may cause damage to EN-43653 holding tool.

1. If equipped, with a manual transmission leave the transmission in first gear with the vehicle on the ground and the parking brake set.
2. If equipped, with an automatic transmission, remove the starter. Refer to «Starter Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid) .
3. Install EN-43653 holding tool.
4. Remove the camshaft. Refer to «Intake Camshaft and Valve Lifter Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) , or «Exhaust Camshaft and Valve Lifter Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
5. Remove the camshaft roller followers (1).
6. Install the EN-43649-10 adaptor set (1) to the front and rear of the cylinder head.
7. Install the cross bars and locks (2) of the EN-43649 compressor to the valve spring compressor adaptors.
8. Remove the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
9. Install an air hose adapter into the spark plug hole.
10. Attach an air hose to the adapter and pressurize the cylinder to 690 kPa (100 psi).
11. Compress the valve spring using the valve spring compressor (3).
12. Remove the valve spring keepers (1).
13. Remove the valve spring (3) and retainer (2).
14. Use the EN-36017 seal remover (1) to remove the valve seal.

1. Using the EN-36017 seal remover (1) install the NEW valve seal. Fully seat the seal onto the valve guide.
2. Install the valve spring (3) and retainer (2).
3. Compress the valve spring using the valve spring compressor.
4. Install the valve spring keepers (1).
5. Disconnect the air hose and air hose adapter.
6. Remove the EN-43649 compressor and EN-43649-10 adaptor set from the cylinder head.
7. Install the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
8. Install the camshaft roller followers.
9. Install the camshaft. Refer to «Intake Camshaft and Valve Lifter Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) , or «Exhaust Camshaft and Valve Lifter Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
10. If used, remove the EN-43653 holding tool.
11. If removed, install the starter. Refer to «Starter Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid) .

Cylinder Head Replacement

Special Tools

1. J 45059 Angle Meter
2. EN-48953 Camshaft Actuator Locking Tool
3. J 38185 Hose Clamp Pliers
4. EN-48749 Timing Chain Retention Tool Kit

1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge) .
2. Remove the exhaust manifold. Refer to «Exhaust Manifold Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/exhaust/#engine-exhaust-system) .
3. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
4. Reposition the radiator surge tank air bleed hose clamp.
5. Remove the radiator surge tank air bleed hose from the cylinder head.
6. Reposition the radiator inlet hose clamp using the J 38185 hose clamp pliers.
7. Remove the radiator inlet hose from the cylinder head.
8. Disconnect all electrical connectors as necessary.
9. Remove the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
10. Remove the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
11. Rotate the crankshaft clockwise to install the EN-48953 camshaft actuator locking tool.
12. Install the EN-48953 camshaft actuator locking tool (1).
13. Install the camshaft actuator tool and tighten bolts to 10 N.m (89 lb in).
14. Remove the upper timing chain guide bolts and guide.
15. Clean the timing chain and gears with solvent.
16. Mark the timing gear sprockets and the timing chain. It is recommended that the paint marks are located in the 12 o'clock position.
17. Loosen, but do not remove the intake and exhaust camshaft actuator bolts.
18. Remove the EN-48953 camshaft actuator locking tool.
19. Install the EN-48749 timing chain retention tool kit (1) to the intake side of the timing chain.
20. Remove the timing chain tensioner.
21. Install the EN-48749 timing chain retention tool kit (1) to the exhaust side of the timing chain.
22. Remove and discard the exhaust camshaft actuator bolt (2).
23. Remove the exhaust cam actuator (3) from the exhaust camshaft while also removing the actuator from the chain.
24. Remove and discard the intake camshaft actuator bolt (2).
25. Remove the intake camshaft actuator (3) from the camshaft while also removing the actuator from the timing chain.
26. Mark the cylinder head (1) in relationship to the camshaft actuator notch is on the camshaft (2).
27. Mark the cylinder head (1) in relationship to the camshaft actuator notch is on the camshaft (2).
28. Remove the fixed timing chain guide access plug.
29. Remove the upper fixed timing chain guide bolt.
30. Install a rubber band (1) around the top of the upper timing chain guides (2) in order to pull the guides together.
31. Remove the cylinder head bolts in the sequence shown. Discard the bolts.
32. Remove the cylinder head.
33. Remove the cylinder head gasket.
34. Clean all of the gasket surfaces.
35. Use the following steps when cleaning the cylinder head and cylinder block surfaces: Use a razor blade gasket scraper to clean the cylinder head and cylinder block gasket surfaces. Do not scratch or gouge either surface. NOTE: DO NOT use any other method or technique to clean these gasket surfaces. Use a NEW razor blade on the cylinder head and a NEW blade on the cylinder block. NOTE: Be careful not to gouge or scratch the gasket surfaces. DO NOT gouge or scrape the combustion chamber surfaces. The feel of the gasket surface is important, not the appearance. There will be indentations from the gasket left in the cylinder head after all of the gasket material is removed. These small indentations will be filled in by the NEW gasket. Hold the razor blade as parallel to the gasket surface as possible.
36. Clean the old sealer/lube and any dirt from around the bolt holes.
37. Clean the bolts holes with a nylon bristle brush.
38. When cleaning the cylinder head bolt holes use suitable commercial spray liquid solvent and compressed air from an extended-tip blow gun in order to reach the bottom of the holes.
39. If replacing the cylinder head, transfer all parts as necessary.

1. Install the cylinder head gasket.
2. Install the cylinder head.
3. Install NEW cylinder head bolts.
4. Install and tighten the cylinder head bolts in the sequence shown to 30 N.m (22 lb ft) plus an additional 155 degrees using the J 45059 angle meter.
5. Install the NEW front cylinder head bolts and tighten the bolts to 35 N.m (26 lb ft).
6. Ensure the cylinder head (1) and the camshaft (2) are correctly aligned.
7. Ensure the cylinder head (1) and the camshaft (2) are correctly aligned.
8. Remove the rubber band (1) from around the top of the upper timing chain guides (2).
9. Install the fixed guide bolt into the cylinder head and tighten to 12 N.m (106 lb in).
10. Apply sealant compound to thread and install the timing chain guide bolt access hole plug. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) for the correct part number.
11. Install the fixed timing chain guide access plug and tighten the plug to 90 N.m (59 lb ft).
12. Install the timing chain onto the intake camshaft actuator.
13. Align the intake camshaft actuator alignment mark made previously with the timing chain mark and install the actuator onto the camshaft.
14. Install a NEW intake camshaft actuator bolt (2) until snug.
15. Remove the EN-48749 timing chain retention tool (1) from the intake side of the timing chain.
16. Install the timing chain onto the exhaust camshaft actuator.
17. Align the exhaust camshaft actuator alignment mark made previously with the timing chain mark and install the actuator onto the camshaft.
18. Install a NEW exhaust camshaft actuator bolt (2) until snug.
19. Remove the EN-48749 timing chain retention tool (1) from the exhaust side of the timing chain.
20. Reset and install the timing chain tensioner. Refer to «Timing Chain Tensioner Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__timing-chain-tensioner-replacement) .
21. Install the EN-48953 camshaft actuator locking tool (1) to the actuators.
22. Install the camshaft actuator locking tool bolts and tighten to 10 N.m (89 lb in).
23. Tighten the NEW camshaft actuator bolt to 30 N.m (22 lb ft), plus an additional 100 degrees using the J 45059 angle meter.
24. Release the tensioner by applying a counterclockwise rotational torque of 45 N.m (33 lb ft) to the harmonic balancer bolt.
25. Remove the camshaft actuator locking tool, EN-48953 camshaft actuator locking tool.
26. Install the upper timing chain guide bolts and guide. Tighten the bolts to 10 N.m (89 lb in).
27. Install the camshaft cover. Refer to «Camshaft Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
28. Install the spark plugs. Refer to «Spark Plug Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
29. Connect all electrical connectors as necessary.
30. Install the radiator inlet hose to the cylinder head.
31. Position the radiator inlet hose clamp using the J 38185 hose clamp pliers.
32. Install the radiator surge tank air bleed hose to the cylinder head.
33. Position the radiator surge tank air bleed hose clamp.
34. Install the exhaust manifold. Refer to «Exhaust Manifold Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/exhaust/#engine-exhaust-system) .
35. Install the intake manifold. Refer to «Intake Manifold Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
36. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge) .

1. Remove the drive belt. Refer to «Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement) .
2. Remove the oil level indicator tube. Refer to «Oil Level Indicator Tube Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
3. Install the engine support fixture. Refer to «Engine Support Fixture»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-support-fixture) .
4. Remove engine mount (4). Refer to «Engine Mount Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
5. Using the engine support fixture, raise the engine approximately 76 mm (3 in).
6. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
7. Loosen the upper air conditioning (A/C) compressor bolts (1).
8. Remove the lower A/C compressor nut and stud (2).
9. Place a suitable drain pan under the oil pan drain plug (1).
10. Remove the oil pan drain plug.
11. Drain the engine oil.
12. Reinstall the oil pan drain plug until snug.
13. Remove the bolts (1) retaining the secondary air injection pump (2) to the oil pan.
14. Tie the secondary air injection pump out of the way of the oil pan.
15. Remove the 4 oil pan to transaxle bolts.
16. Remove the oil pan bolts.
17. Remove the oil pan
18. Remove any old oil pan sealant (1).

1. Ensure that the oil pan and the sealing surface on the lower crankcase are free of all oil and debris.
2. Apply a 2 mm bead of sealant (1) around the perimeter of the oil pan and the oil suction port opening. DO NOT over apply the sealant. More than a 2 mm bead is not required. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
3. Install the oil pan.
4. Install the oil pan bolts.
5. Install the 4 oil pan to transaxle bolts and tighten to 75 N.m (55 lb ft).
6. Tighten the oil pan bolts in the sequence shown to 25 N.m (18 lb ft).
7. Position the secondary air injection pump (2) to the oil pan.
8. Install the injection pump bolts (1) and tighten to 25 N.m (18 lb ft).
9. Lower the vehicle.
10. Using the engine support fixture, lower the engine.
11. Install the engine mount. Refer to «Engine Mount Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
12. Remove the engine support fixture.
13. Install the oil level indicator tube. Refer to «Oil Level Indicator Tube Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
14. Install the drive belt. Refer to «Drive Belt Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__drive-belt-replacement) .
15. Fill the engine oil to the proper level.

Scheme 30

Automatic Transmission Flex Plate Replacement

Crankshaft Rear Oil Seal Replacement

Special Tools

EN-42067 Rear Main Seal Installer

For equivalent regional tools, refer to Special Tools .

1. Remove the flex plate. Refer to «Automatic Transmission Flex Plate Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
2. Pry out the crankshaft rear oil seal using a flat-bladed tool.

1. Using the EN-42067 installer, install a NEW crankshaft real oil seal.
2. Install the flex plate. Refer to «Automatic Transmission Flex Plate Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
2. Remove the air cleaner outlet duct assembly. Refer to «Air Cleaner Outlet Duct Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
3. Remove the intake manifold cover (2). Refer to «Intake Manifold Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l)
4. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__fuel-pressure-relief) .
5. Disconnect the fuel feed pipe quick connect fitting at the fuel pump. Refer to «Metal Collar Quick Connect Fitting Service»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__metal-collar-quick-connect-fitting-service) .
6. Disconnect the evaporative emission (EVAP) line quick connect fitting from the EVAP purge solenoid. Refer to «Plastic Collar Quick Connect Fitting Service»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
7. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge)
8. Disconnect the transaxle shift cable clip (1) from the fuel line bracket.
9. Remove the battery tray. Refer to «Battery Tray Replacement»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid) .
10. Reposition the hose clamp (1) and disconnect the radiator inlet hose (2). Refer to «Radiator Inlet Hose Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
11. Remove the starter generator. Refer to «Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
12. Reposition the vacuum brake booster hose clamp (3) at the intake manifold.
13. Disconnect the vacuum brake booster hose (4) from the intake manifold. Reposition the brake booster hose out of the way.
14. Reposition the coolant recovery inlet hose clamp (2) at the cylinder head.
15. Disconnect the coolant recovery inlet pipe clip from the fuel pump cover.
16. Disconnect the coolant recovery inlet hose (1) from the cylinder head. Reposition the hose/pipe out of the way.
17. Remove the radiator outlet hose. Refer to «Radiator Outlet Hose Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
18. Reposition the heater inlet hose clamp (1) at the thermostat housing.
19. Disconnect the heater inlet hose (2) from the thermostat housing.
20. Reposition the coolant recovery reservoir/heater inlet hose (3) clamp at the thermostat housing.
21. Disconnect the coolant recovery reservoir/heater inlet hose (4) from the thermostat housing.
22. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
23. Drain the engine oil. Refer to «Engine Oil and Oil Filter Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-oil-and-oil-filter-replacement) .
24. Remove the secondary air injection pump. Refer to «Secondary Air Injection Pump Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
25. Unbolt the A/C compressor and reposition out of the way.
26. Remove the starter motor. Refer to «Starter Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid)
27. Remove the front wheels and tires. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/ii-2009-2013/remont/wheel-tire-system/#tires-and-wheels) .
28. Remove the front wheelhouse panel. Refer to «Front Compartment Splash Shield Replacement»(/buick/lacrosse/ii-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
29. Remove the catalytic converter. Refer to «Catalytic Converter Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/exhaust/#engine-exhaust-system) .
30. Disconnect the tie rods from the steering knuckles. Refer to «Steering Linkage Outer Tie Rod Replacement»(/buick/lacrosse/ii-2009-2013/remont/manual-power-steering/#power-steering-system) .
31. Disconnect the stabilizer links from the stabilizer shaft. Refer to «Stabilizer Shaft Link Replacement»(/buick/lacrosse/ii-2009-2013/remont/suspension-front/#front-suspension-system) .
32. Disconnect the lower control arms from the steering knuckles. Refer to «Lower Control Arm Replacement (GNB)»(/buick/lacrosse/ii-2009-2013/remont/suspension-front/#front-suspension-system) , «Lower Control Arm Replacement (GNA)»(/buick/lacrosse/ii-2009-2013/remont/suspension-front/#front-suspension-system) .
33. Remove the wheel drive shafts. Refer to «Front Wheel Drive Shaft Replacement (GNB)»(/buick/lacrosse/ii-2009-2013/remont/axle-shafts/#wheel-drive-shafts__front-wheel-drive-shaft-replacement-gnb) , «Front Wheel Drive Shaft Replacement (GNA)»(/buick/lacrosse/ii-2009-2013/remont/axle-shafts/#wheel-drive-shafts__front-wheel-drive-shaft-replacement-gna) .
34. Install a piece of hardwood 1 x 2 x 4 between the transaxle and the frame.
35. Install a piece of hardwood 1 x 2 x 4 between the oil pan and the frame.
36. Drain the transaxle fluid.
37. Remove the transaxle oil cooler hoses from the transaxle. Refer to «Transmission Fluid Cooler Outlet Pipe Replacement»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-repair-instructions-on-vehicle) , and «Transmission Fluid Cooler Inlet Pipe Replacement»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-repair-instructions-on-vehicle) .
38. Lower the vehicle.
39. Remove the transaxle shift cable from the range select lever.
40. Release the shift control cable retaining clip and remove the cable from the shift control cable bracket.
41. Using long tie straps, secure the radiator/condenser/fan assembly to the radiator support.
42. Disconnect the intermediate shaft from the steering gear. Refer to «Intermediate Steering Shaft Replacement»(/buick/lacrosse/ii-2009-2013/remont/steering-column-switches/#steering-wheel-and-steering-column) .
43. Remove the engine mount to bracket bolts (1).
44. Remove the transaxle mount to transaxle bolts.
45. Disconnect the following electrical connectors: ECM connectors Transmission connector Engine harness connector at the underhood fuse block Main engine harness to body harness connector Transmission auxiliary fluid pump connector
46. Position the disconnected engine harness on the engine
47. Raise the vehicle.
48. Position an engine support table under the powertrain assembly.
49. With the table positioned, fully raise the table to contact with the powertrain assembly.
50. Remove the frame to body bolts. Refer to «Drivetrain and Front Suspension Frame Replacement»(/buick/lacrosse/ii-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
51. Carefully lower the engine table and raise the body on the hoist until the engine/transaxle and frame are separated from the vehicle.
52. Remove the torque converter to flexplate bolts (1).
53. Install a suitable lifting device to the engine.
54. Disconnect the engine harness connectors as necessary.
55. Remove the transaxle bolts from the engine.
56. Separate the engine from the transaxle.
57. Install the engine to a suitable engine stand.

1. Install a suitable lifting device to the engine.
2. Using the lifting device, position and install the engine to the transaxle.
3. Install the transaxle bolts to the engine and tighten to 75 N.m (55 lb ft).
4. Install the torque converter to flexplate bolts (1) and tighten to 60 N.m (44 lb ft).
5. Remove the engine lifting device.
6. Position the powertrain support table under the vehicle.
7. Raise the powertrain into position under the vehicle.
8. With the table positioned, if required, lower the vehicle over the powertrain.
9. Align the lower radiator pins with the frame. Ensure all hoses and electrical harnesses are correctly routed and free from the loading path of the powertrain.
10. Install the NEW frame to body bolts. Refer to «Drivetrain and Front Suspension Frame Replacement»(/buick/lacrosse/ii-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody)
11. Lower the vehicle.
12. Install the transaxle mount to transaxle bolts and tighten to 55 N.m (41 lb ft).
13. Install the engine mount to bracket bolts (1) and tighten to 50 N.m (37 lb ft).
14. Connect the following electrical connectors: ECM connectors Transmission connector Engine harness connector at the underhood fuse block Main engine harness to body harness connector Transmission auxiliary fluid pump connector
15. Raise and support the vehicle.
16. Install the wheel drive shafts. Refer to «Front Wheel Drive Shaft Replacement (GNB)»(/buick/lacrosse/ii-2009-2013/remont/axle-shafts/#wheel-drive-shafts__front-wheel-drive-shaft-replacement-gnb) , «Front Wheel Drive Shaft Replacement (GNA)»(/buick/lacrosse/ii-2009-2013/remont/axle-shafts/#wheel-drive-shafts__front-wheel-drive-shaft-replacement-gna) .
17. Connect the control arm to the steering knuckles. Refer to «Lower Control Arm Replacement (GNB)»(/buick/lacrosse/ii-2009-2013/remont/suspension-front/#front-suspension-system) , «Lower Control Arm Replacement (GNA)»(/buick/lacrosse/ii-2009-2013/remont/suspension-front/#front-suspension-system) .
18. Connect the stabilizer links to the stabilizer shaft. Refer to «Stabilizer Shaft Link Replacement»(/buick/lacrosse/ii-2009-2013/remont/suspension-front/#front-suspension-system) .
19. Connect the outer tie rods to the steering knuckles. Refer to «Steering Linkage Outer Tie Rod Replacement»(/buick/lacrosse/ii-2009-2013/remont/manual-power-steering/#power-steering-system) .
20. Connect the intermediate shaft to the steering gear. Refer to «Intermediate Steering Shaft Replacement»(/buick/lacrosse/ii-2009-2013/remont/steering-column-switches/#steering-wheel-and-steering-column) .
21. Install the catalytic converter. Refer to «Catalytic Converter Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/exhaust/#engine-exhaust-system) .
22. Connect the transaxle oil cooler hoses to the transaxle. Refer to «Transmission Fluid Cooler Outlet Pipe Replacement»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-repair-instructions-on-vehicle) , and «Transmission Fluid Cooler Inlet Pipe Replacement»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-repair-instructions-on-vehicle) .
23. Remove the wood from between the oil pan and the frame.
24. Remove the wood from between the transaxle and the frame.
25. Install the front wheelhouse panel. Refer to «Front Compartment Splash Shield Replacement»(/buick/lacrosse/ii-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
26. Install the front wheels and tires. Refer to «Tire and Wheel Removal and Installation»(/buick/lacrosse/ii-2009-2013/remont/wheel-tire-system/#tires-and-wheels) .
27. Lower the vehicle.
28. Position the radiator/condenser/fan assembly. Remove the tie straps.
29. Install the shift control cable to the shift control cable bracket and engage the shift control cable retaining clip.
30. Install the transaxle shift cable to the range select lever.
31. Raise and support the vehicle.
32. Install the A/C compressor with the bolts and tighten to 50 N.m (37 lb ft).
33. Install the starter motor. Refer to «Starter Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid)
34. Install the secondary air injection pump. Refer to «Secondary Air Injection Pump Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
35. Lower the vehicle.
36. Connect the coolant recovery reservoir/heater inlet hose (4) to the thermostat housing.
37. Position the coolant recovery reservoir/heater inlet hose clamp (3) at the thermostat housing.
38. Connect the heater inlet hose (3) to the thermostat housing.
39. Position the heater inlet hose clamp (1) at the thermostat housing.
40. Connect the vacuum brake booster hose (4) at the intake manifold.
41. Install the vacuum brake booster hose clamp (3).
42. Install the starter generator. Refer to «Starter Generator Replacement»(/buick/lacrosse/ii-2009-2013/remont/body-electrical/#hybridev-control-system__starter-generator-replacement)
43. Install the radiator outlet hose. Refer to «Radiator Outlet Hose Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
44. Connect the coolant recovery inlet hose (1) to the cylinder head.
45. Connect the coolant recovery inlet pipe clip to the fuel rail.
46. Position the coolant recovery inlet hose clamp (2) at the cylinder head.
47. Connect the radiator inlet hose (2) and reposition the hose clamp (1). Refer to «Radiator Inlet Hose Replacement (LUK)»(/buick/lacrosse/ii-2009-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
48. Install the battery tray. Refer to «Battery Tray Replacement»(/buick/lacrosse/ii-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-except-hybrid) .
49. Connect the fuel feed pipe quick connect fitting at the fuel pump. Refer to «Metal Collar Quick Connect Fitting Service»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__metal-collar-quick-connect-fitting-service) .
50. Install the intake manifold cover (2). Refer to «Intake Manifold Cover Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l)
51. Install the air cleaner outlet duct assembly. Refer to «Air Cleaner Outlet Duct Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions)
52. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions) .
53. Fill the transaxle with fluid. Refer to «Transmission Fluid Drain and Fill»(/buick/lacrosse/ii-2009-2013/remont/automatic-trans/#automatic-transmission-6t40-repair-instructions-on-vehicle) .
54. Refill the engine with oil. Refer to «Engine Oil and Oil Filter Replacement»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-oil-and-oil-filter-replacement) .
55. Perform the CKP system variation learn procedure. Refer to «Crankshaft Position System Variation Learn»(/buick/lacrosse/ii-2009-2013/remont/testing-diagnostics/#engine-controlsfuel-24l-repair-instructions__crankshaft-position-system-variation-learn) .
56. Start the engine and allow the engine to run, inspect for leaks. Correct as necessary.

Engine Oil and Oil Filter Replacement

Special Tools

EN-44887 Oil Filter Wrench

For equivalent regional tools, refer to Special Tools

1. Place a collecting pan underneath the oil filter.
2. Use EN-44887 wrench to remove the oil filter cap (1) and seal.
3. Remove and properly dispose of the oil filter insert (2).
4. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/lacrosse/ii-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
5. Place a collecting pan underneath the oil drain plug.
6. Remove the oil drain plug (1) and seal (2).

1. Clean the oil drain plug thread and the thread in the oil pan.
2. Install a seal (2) to the oil drain plug (1).
3. Install the oil drain plug to the oil pan and tighten to 25 N.m (18 lb ft).
4. Lower the vehicle.
5. Use EN-44887 wrench to Install a NEW oil filter (2) and a NEW seal and tighten the oil filter cap (1) to 22 N.m (16 lb ft).
6. Fill in NEW engine oil. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
7. Reset the service interval indicator.

Draining Fluids and Oil Filter Removal

Special Tools

EN-44887 Oil Filter Wrench

For equivalent regional tools, refer to Special Tools .

1. Use EN-44887 wrench to remove the oil filter cap (1). Remove the oil pan drain plug and allow the oil to drain out.
2. Remove the oil filter (2) from the cap and discard.
3. Clean the oil filter housing in the engine block.
4. Install the oil pan drain plug and tighten to 25 N.m (18 lb ft).
5. Remove the water pump drain plug from the water pump and allow the coolant to drain from the water jacket.
6. Apply sealant to the water pump drain plug. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
7. Install the water pump drain plug and tighten to 20 N.m (15 lb ft).
8. If cleaning or repairing the engine block, it is not necessary to reinstall the plugs.

Crankshaft Balancer Removal

Special Tools

EN 43653 Flywheel Holding Tool

For equivalent regional tools, refer to Special Tools

1. Install EN 43653 holding tool (1) in the starter assembly location, engaging the flywheel, in order to prevent crankshaft rotation.
2. Remove the balancer retaining bolt (1) and washer. Discard the bolt.
3. Remove the balancer (2) using a universal removal tool.

Engine Flywheel Removal

Special Tools

EN 43653 Flywheel Holding Tool

For equivalent regional tools, refer to Special Tools

1. Ensure that EN 43653 tool is installed and engaging the flywheel to prevent crankshaft rotation.
2. Remove the flywheel attaching bolts.
3. Remove the flywheel.
4. Remove EN 43653 tool.

Oil Level Indicator and Tube Removal (LUK)

1. Remove knock sensor connector (4) from the oil level indicator tube.
2. Remove the electrical wiring harness from the oil level indicator tube.
3. Remove the oil level indicator tube bracket bolt (3).
4. Remove the oil level indicator (2) and the oil level indicator tube (1) from the oil pan.
5. Inspect the O-ring and replace if necessary.

Exhaust Manifold Removal (LUK)

1. Remove the secondary air injection bolts (2) and nuts (1).
2. Remove the secondary air injection studs (3 and 4).
3. Remove the secondary air injection valve assembly (1).
4. Remove the secondary air injection gasket (2) and discard.
5. Remove the oxygen sensor (1).
6. Remove the exhaust manifold heat shield bolts.
7. Remove the exhaust manifold heat shield (1).
8. Remove the block heater (1), if equipped.
9. Remove and discard the exhaust manifold to cylinder head retaining nuts (1).
10. Remove the exhaust manifold (2).
11. Remove the exhaust manifold gasket (3).
12. Clean all of the sealing surfaces.
13. If the exhaust manifold is being replaced, transfer the following parts: The exhaust manifold heat shield The oxygen sensor
14. Remove the secondary air injection pipe assembly bolts (2).
15. Remove the secondary air injection pipe assembly (1).

Intake Manifold Removal

1. Remove the oil fill cap (1).
2. Remove the intake manifold cover (2).
3. Remove the oil fill tube assembly (3) and O-ring (4).
4. Remove the evaporative (EVAP) emission canister valve tube (1).
5. Remove the EVAP canister valve (2).
6. Remove the MAP sensor (3).
7. Remove the throttle body (1).
8. Remove the fuel pump cover nut, bolts, and cover (3).
9. Remove the bracket bolt and low pressure fuel pipe assembly (1).
10. Remove the fuel pump insulator (2).
11. Remove and discard the fuel feed intermediate pipe (1).
12. Remove the fuel pump assembly (4).
13. Remove and discard the fuel pump housing O-ring (2) and gasket (3).
14. Remove the fuel pump roller lifter (1).
15. Remove the fuel rail harness connector bracket bolt (1) and intake manifold insulator bolt.
16. Remove the intake manifold insulator (2).
17. Remove the intake manifold retaining nuts and bolts.
18. Remove the intake manifold (1).
19. If the intake manifold needs to be replaced, transfer the throttle body to the new intake manifold.

Fuel Rail and Injectors Removal

Special Tools

EN-49248 Fuel Rail Assembly Remover

For equivalent regional tools, refer to Special Tools

1. Remove the fuel injection fuel rail noise shield (1).
2. Disconnect the electrical harness from the fuel rail harness connection.
3. Disconnect all 4 fuel injector electrical connections.
4. Remove the fuel rail assembly retaining bolts.
5. Install EN-49248 studs (1) into the 2 center fuel rail assembly retaining bolt locations. Tighten the studs to 22 N.m (16 lb ft).
6. Install EN-49248 remover (2) onto each stud, and engage the hooks to the fuel rail. Install the nuts (3) retaining the remover onto the studs and tighten until snug.
7. Using EN-49248 remover, remove the fuel rail assembly (1).

Camshaft Cover Removal (LUK)

1. Remove the rear lift bracket (1).
2. Remove the front lift bracket (1).
3. Remove the ignition coil (1).
4. Remove the camshaft housing cover insulator (1).
5. Remove the camshaft cover assembly (1).
6. Remove and discard the camshaft cover gasket, camshaft cover grommets, and camshaft cover bolts if they are serviced with the grommet.

Engine Front Cover and Oil Pump Removal

1. Remove only the upper drive belt tensioner bolt (3).
2. Remove the drive belt tensioner pivot bolt (2).
3. Remove the accessory drive belt tensioner (1).
4. Inspect the drive belt tensioner assembly (1). Replace the assembly if necessary, or if any of the following conditions exist: The tensioner spring lower shoulder bolt (4) shows wear or signs it has been removed or tampered with. This bolt should NEVER be removed when servicing. The drive belt tensioner pivot bolt (2) has thread or hex head wear and requires replacement. The drive belt tensioner assembly and bolts are always replaced at the same time.
5. Remove the drive belt tensioner bracket bolts.
6. Remove the drive belt tensioner bracket.
7. Remove the engine front cover bolts.
8. Remove the long water pump bolt.
9. Remove the engine front cover and gaskets.
10. Remove the crankshaft front cover oil seal with an appropriate tool.

Camshaft Timing Chain and Tensioner Removal (LUK)

Special Tools

EN-48953 Camshaft Actuator Locking Tool

For equivalent regional tools, refer to Special Tools .

1. Rotate the crankshaft to install EN-48953 locking tool (1).
2. Install EN-48953 locking tool onto the cylinder head and tighten to 10 N.m (89 lb in). If the intake camshaft actuator is moving independent of cam and is not locked, rotate the intake camshaft counterclockwise and the tool will hold the actuator, locking the actuator to the cam.
3. Loosen the intake camshaft actuator bolt.
4. Loosen the exhaust camshaft actuator bolt.
5. Remove EN-48953 locking tool.
6. Remove the upper timing chain guide bolts.
7. Remove the upper timing chain guide (1).
8. Remove the timing chain tensioner plunger (1).
9. Locate hex on the exhaust camshaft and hold with a wrench (2).
10. Remove the exhaust camshaft bolt and the exhaust camshaft actuator (1). Discard the bolt.
11. Remove the adjustable timing chain guide bolt.
12. Remove the adjustable timing chain guide (1).
13. Remove the plug (1) to gain access to the fixed timing chain guide bolt.
14. Remove the fixed timing chain guide bolts.
15. Remove the fixed timing chain guide (1).
16. Locate hex on the intake camshaft and hold with a wrench.
17. Remove the intake camshaft actuator bolt, the intake camshaft actuator (1) and the timing chain (2) through the top of the cylinder head. Discard the bolt.
18. Mark the cylinder head where the exhaust camshaft actuator locking notch (1) and intake camshaft locking notch (2) are lined up with the cylinder head.
19. Remove the crankshaft sprocket (2) and friction washers (1), if equipped.
20. Remove the timing chain oil nozzle bolt.
21. Remove the timing chain oil nozzle (1).

Intake Camshaft and Components Removal

1. Remove the intake camshaft position actuator solenoid valve bolt (1) and valve (2).
2. Remove the rear cylinder head cover plate (1).
3. Remove the intake camshaft bearing rear cap bolts and cap (2).
4. Mark camshaft caps to ensure they are installed in the same position.
5. Remove the intake camshaft cap bolts.
6. Remove the camshaft caps (1).
7. Remove the intake camshaft (3).
8. Remove the intake camshaft roller finger followers.
9. Remove the hydraulic lash adjusters.

Exhaust Camshaft and Components Removal

1. Remove the exhaust camshaft position actuator solenoid valve bolt (1) and valve (2).
2. Mark camshaft caps to ensure they are installed in the same position.
3. Remove the exhaust camshaft cap bolts.
4. Remove the camshaft caps ensuring they are marked and refitted in same position on assembly.
5. Remove the exhaust camshaft.
6. Remove the exhaust camshaft roller finger followers.
7. Remove the hydraulic lash adjusters.

Water Pump and Balance Shaft Chain and Tensioner Removal

1. Remove the balance shaft drive chain tensioner bolts.
2. Remove the balance shaft drive chain tensioner (1).
3. Remove the adjustable balance shaft chain guide bolt.
4. Remove the adjustable balance shaft chain guide (1).
5. Remove the small balance shaft drive chain guide bolts.
6. Remove the small balance shaft drive chain guide (1).
7. Remove the upper balance shaft drive chain guide bolts.
8. Remove the upper balance shaft drive chain guide (1).
9. Remove the balance shaft drive chain (1).
10. Remove the balance shaft drive sprocket (2).

Balance Shaft Removal

Note. This procedure is not used in Europe.

Special Tools

EN-43650 Balancer Shaft Bearing Remover and Installer

For equivalent regional tools, refer to Special Tools .

1. Remove the balance shaft bearing carrier bolts.
2. Remove the balance shaft assemblies (1).
3. Install the EN-43650 remover (1) into the balance shaft hole. Insert the tool with the foot parallel to the shaft.
4. When the EN-43650 remover (1) is inserted in the block turn the EN-43650 remover so that the foot becomes perpendicular to the shaft.
5. Center the foot of the EN-43650 remover on the balance shaft bushing.
6. Once the EN-43650 remover is centered on the balance shaft bushing, then insert the centering guide into the front balance shaft bore and tighten the nut with an appropriate wrench (2). When the EN-43650 remover is properly installed, before removing the bushing, the end of the tool should be 116 mm (4.6 in) (a) from the block face. If the EN-43650 remover is less than approximately 114 mm (4.5 in) (a), recheck the tool alignment.
7. Tighten the nut on the EN-43650 remover (1) until the tension releases. When the tension releases, remove the EN-43650 remover and the balance shaft bushing (2).

Water Pump Removal

1. Remove the engine coolant temperature sensor (1).
2. Remove the thermostat and water feed pipe retaining bolts.
3. Remove the thermostat housing and water feed pipe (1) from the water pump cover.
4. Remove the water pump retaining bolts. Be sure to remove the bolt that goes through the front of the engine block.
5. Remove the water pump assembly (1).

Cylinder Head Removal (LUK)

Special Tools

EN 38188 Cylinder Head Broken Bolt Extractor Kit

For equivalent regional tools, refer to Special Tools

1. Remove the cylinder head to the block bolts in sequence. Discard the bolts.
2. Remove the cylinder head.
3. Remove the cylinder head gasket.
4. Clean all of the gasket surfaces.
5. Use the following procedures when cleaning the cylinder head and cylinder block surfaces: Use a razor blade gasket scraper to clean the cylinder head and cylinder block gasket surfaces. Do not scratch or gouge any surface. NOTE: Do not use any other method or technique to clean these gasket surfaces. Use a new razor blade for each cylinder head and cylinder block. NOTE: Be careful not to gouge or scratch the gasket surfaces. Do not gouge or scrape the combustion chamber surfaces. The feel of the gasket surface is important, not the appearance. There will be indentations from the gasket left in the cylinder head after all of the gasket material is removed. These small indentations will be filled in by the new gasket. Hold the razor blade as parallel to the gasket surface as possible.
6. Clean the old sealer/lube and dirt from the bolt holes.
7. Clean the bolt holes with a nylon bristle brush.
8. When cleaning the cylinder head bolt holes use a suitable commercial spray liquid solvent and compressed air from an extended-tip blow gun to reach the bottom of the holes.
9. Remove any broken long cylinder head bolts using the EN 38188 kit.

Oil Pan Removal

1. Remove the oil pan bolts.
2. Remove the oil pan at pry points.

EN-43966-1 Connecting Rod Guides

For equivalent regional tools, refer to Special Tools .

1. Rotate the crankshaft to a position where the connecting rod bolts are the most accessible.
2. Mark the connecting rod and cap with the cylinder position. Also mark their orientation. This will ensure the caps and connecting rods are re-assembled properly.
3. Remove any ridge at the top of the cylinder bore to avoid damage to the piston ring lands.
4. Remove the connecting rod bolts.
5. Remove the connecting rod cap (1).
6. Install EN-43966-1 guides (2) on the connecting rod bolts before removing the piston and connecting rod assembly.
7. Remove the piston and connecting rod assembly (1).

Lower Crankcase Removal

1. Remove the bedplate perimeter bolts (3).
2. Remove and discard the crankshaft bearing bolts (2).
3. Using the pry-points and an appropriate prying tool, gently separate the upper and lower crankcase (1).

Crankshaft and Bearing Removal

1. Remove the crankshaft (1) from the block.
2. Remove the crankshaft rear oil seal (2) from the block.
3. Remove the bearing inserts (1) from the block (2).
4. Remove the bearing inserts (1) from the bed plate (2).
5. Clean the oil, sludge, and carbon.
6. Inspect the oil passages for obstructions.
7. Inspect the threads.
8. Inspect the bearing journals and the thrust surfaces for the following conditions: Cracks Chips Gouges Roughness Grooves Overheating (discoloration)
9. Inspect the corresponding bearing inserts for imbedded foreign material. If foreign material exists find the cause and repair it.
10. Measure the crankshaft journals. Use a micrometer or dial indicator to measure the taper and runout. Note the result for the later selection of bearing inserts. If not within limits the crankshaft must be replaced. Note the location of the main bearing high spots. If they are not in line, the crankshaft is bent and must be replaced.

Engine Block Disassemble

1. Remove the engine block coolant drain plug.
2. Remove the oil flow check valve.
3. Remove the rear oil passage plugs (3).
4. Remove the 3 oil passage plugs on each side of the block (2).
5. Remove the 2 water passage plugs on the top of the block (1).
6. Remove the 2 front oil passage plugs.
7. Remove the knock sensor (1) and bolt.
8. Remove the oil pressure switch (2).
9. Remove the crankshaft position (CKP) sensor (1) and bolt.
10. If equipped, loosen the piston oil nozzle assembly (1) bolt and remove the piston oil nozzle assembly.

Engine Block Cleaning and Inspection

Special Tools

1. EN-8087 Cylinder Bore Gauge
2. GE-7872 Magnetic Base Dial Indicator

For equivalent regional tools, refer to Special Tools .

1. Clean the sealing material from the gasket mating surfaces (2) with a suitable tool (1).
2. Clean the engine block and lower crankcase in a cleaning tank with solvent appropriate for aluminum.
3. Flush the engine block with clean water or steam.
4. Clean the oil passages.
5. Clean the blind holes.
6. Inspect the cylinder bores for glazing. If the bore is glazed but otherwise serviceable, refer to Deglazing Procedure in «Cylinder Boring and Honing (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
7. Spray the cylinder bores and the machined surfaces with engine oil.
8. Inspect the threaded holes. Clean the threaded holes with a rifle brush. If necessary, drill out the holes and install thread inserts. Refer to «Thread Repair»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__thread-repair) .
9. Use a straight edge (1) and a feeler gauge (2) to check the deck surface for flatness. Carefully machine minor irregularities. Replace the block if more than 0.254 mm (0.010 in) must be removed.
10. Inspect the oil pan rail for nicks. Inspect the front cover attaching area for nicks. Use a flat mill file to remove any nicks.
11. Clean the sealing material from the gasket mating surfaces on the lower crankcase engine block side with a suitable tool (1).
12. Clean the sealing material from the gasket mating surfaces on the lower crankcase oil pan side with a suitable tool (1).
13. Inspect the mating surfaces of the transmission face.
14. Use the following procedure in order to measure the engine block flange runout at the mounting bolt hole bosses: Temporarily install the crankshaft and upper bearings. Measure the crankshaft flange runout using the GE-7872 dial indicator (1) Hold the gauge plate flat against the crankshaft flange. Place the dial indicator stem on the transmission mounting bolt hole boss. Set the indicator to 0. Record the readings obtained from all of the bolt hole bosses. The measurements should not vary more than 0.203 mm (0.008 in). Recheck the crankshaft flange runout if the readings vary more than 0.203 mm (0.008 in). Remove the crankshaft and bearings.
15. Install the bed plate and bolts. Tighten the bed plate bolts to specification.
16. Inspect the crankshaft main bearing bores. Use the EN-8087 gauge (1) to measure the bearing bore concentricity and alignment. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
17. Replace the engine block and bed plate if the crankshaft bearing bores are out of specification.
18. Remove the bed plate.

Measuring Cylinder Bore Diameter

1. Measure the cylinder bore diameter 37 mm (1.457 in) from the deck face using the EN-8087 gauge.
2. Compare your results with the «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) . If the cylinder diameter exceeds the specifications, the cylinder block may be oversized to 0.25 mm (0.010 in). There is only one size of oversized pistons and rings available for service. Refer to «Cylinder Boring and Honing (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Measuring Cylinder Bore Taper

1. Measure the cylinder bore along the thrust surfaces, perpendicular to the crankshaft centerline, at 13 mm (0.510 in) below the deck surface (1) and record your measurement.
2. Measure the cylinder bore along the thrust surfaces, perpendicular to the crankshaft centerline, at 100 mm (3.938 in) below the deck surface (2) and record your measurement.
3. Calculate the difference between the 2 measurements. The result will be the cylinder taper.
4. Compare your results with the «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) . If the cylinders exceed the specifications, the cylinder block may be oversized to 0.25 mm (0.010 in). There is only one size of oversized pistons and rings available for service. Refer to «Cylinder Boring and Honing (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Measuring Cylinder Bore Out-of-Round

1. Measure both the thrust and non-thrust cylinder diameter at 13 mm (0.510 in) below the deck surface (1). Record your measurements.
2. Calculate the difference between the 2 measurements. The result will indicate out-of-round at the upper end of the cylinder.
3. Measure both the thrust and non-thrust cylinder diameter at 100 mm (3.938 in) below the deck surface (2). Record your measurements.
4. Calculate the difference between the 2 measurements. The result will indicate out-of-round at the lower end of the cylinder.
5. Compare your results with the «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) . If the cylinders exceed these specifications, the cylinder block may be oversized to 0.25 mm (0.010 in). There is only one size of oversized pistons and rings available for service. Refer to «Cylinder Boring and Honing (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Boring Procedure

1. Measure all pistons with a micrometer to determine the cylinder bore diameter. Refer to «Engine Block Cleaning and Inspection»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-block-cleaning-and-inspection) .
2. Before you use any type of boring bar, use a fine file and clean the top of the cylinder block, removing any dirt or burrs. If you do not check the cylinder block, the boring bar may be improperly positioned or tilted and the cylinder bore could be bored at an incorrect angle.
3. Carefully follow the instructions furnished by the manufacturer regarding use of the equipment.
4. When you bore the cylinders, ensure all the crankshaft bearing caps are in place. Tighten the crankshaft bearing caps to the proper torque in order to avoid distortion of the cylinder bores during final assembly.
5. When you take the final cut with a boring bar, leave 0.03 mm (0.001 in) on the cylinder bore diameter for the finish honing and fit of the piston.

Honing Procedure

1. When honing the cylinders, follow the manufacturer's recommendations for equipment use, cleaning, and lubrication. Use only clean, sharp stones of the proper grade for the amount of material you remove. Dull, dirty stones cut unevenly and generate excessive heat. Do not hone to final clearance with a coarse or medium-grade stone. Leave sufficient metal so that all stone marks may be removed with fine-grade stones. Perform final honing with a fine-grade stone, honing the cylinder to the proper clearance.
2. During the honing operation, thoroughly clean the cylinder bore. Repeatedly check the cylinder bore for fit with the selected piston.
3. When honing a cylinder for fit to an oversize piston, first perform the preliminary honing with a 100-grit stone.
4. Perform final cylinder honing with a 240-grit stone and obtain a 45 degree cross hatch pattern.
5. The finish marks should be clean but not sharp. The finish marks should also be free from imbedded particles and torn or folded metal.
6. By measuring the selected piston at the sizing point and by adding the average of the clearance specification, you can determine the final cylinder honing dimension required.
7. After final honing and before the piston is checked for fit, clean the cylinder bores with hot water and detergent. Scrub the bores with a stiff bristle brush and rinse the bores thoroughly with hot water. Do not allow any abrasive material to remain in the cylinder bores. This abrasive material may cause premature wear of the new piston rings and the cylinder bores. Abrasive material will also contaminate the engine oil and may cause premature wear of the bearings. After washing the cylinder bore, dry the bore with a clean rag.
8. Perform final measurements of the piston and the cylinder bore.
9. Permanently mark the top of the piston for the specific cylinder to which it has been fitted.
10. Apply clean engine oil to each cylinder bore in order to prevent rusting.

Deglazing Procedure

1. If the bore is glazed but otherwise serviceable, lightly break the glaze with a hone. Replace the piston rings. Refer to «Piston, Connecting Rod, and Bearing Installation (LAF, LAT, LE5, LE9, LEA, or LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__piston-connecting-rod-and-bearing-installation) .
2. Using a ball type or self centering honing tool, deglaze the cylinder bore lightly. Deglazing should be done only to remove any deposits that may have formed. Use a 240-grit stone of silicone carbide, or equivalent, material when preforming the deglazing procedure. The honing stones must be clean, sharp, and straight. Move the hone slowly up and down to produce a 45 degree cross-hatch pattern. Clean the bore thoroughly with soap and water. Dry the bore. Rub clean engine oil in the bore. Re-measure the bore.
3. If the cylinder bore is out of specification, the cylinder bore may be oversized to 0.25 mm (0.010 in). There is only one size of oversized pistons and rings available for service.
4. If honing is not required, clean the cylinder bores with hot water and detergent. Apply clean engine oil to the bore after washing and drying the bore.

Crankshaft Balancer Cleaning and Inspection

1. Clean the crankshaft balancer (1).
2. Clean the belt grooves of all dirt or debris with a wire brush.
3. Dry the crankshaft balancer with compressed air.
4. Inspect the crankshaft balancer for the following: Worn, grooved, or damaged hub seal surface A crankshaft balancer hub seal surface with excessive scoring, grooves, rust or other damage must be replaced. NOTE: In order for the belt to track properly, the belt grooves should be free of all dirt or debris. Dirty or damaged belt grooves The balancer belt grooves should be free of any nicks, gouges, or other damage that may not allow the belt to track properly. Minor imperfections may be removed with a fine file. Worn, chunking or deteriorated rubber between the hub and pulley

Engine Flywheel Cleaning and Inspection

1. Clean the flywheel in solvent.
2. Dry the flywheel with compressed air.
3. Inspect the flywheel for the following: Damaged ring gear teeth Stress cracks around the flywheel-to-crankshaft bolt hole locations Weight saving holes

Crankshaft and Bearing Cleaning and Inspection

Special Tools

GE-7872 Magnetic Base Dial Indicator Set

For equivalent regional tools, refer to Special Tools .

1. Clean the crankshaft (1) with solvent.
2. Thoroughly clean all oil passages and inspect for restrictions or burrs.
3. Dry the crankshaft with compressed air.
4. Perform a visual inspection of the crankshaft for damage.
5. The crankshaft position reluctor ring (1) may be replaced if damaged. Tighten the crankshaft position reluctor ring bolts to 15 N.m (11 lb ft).
6. Inspect the crankshaft journals for wear (1). The journals should be smooth, with no signs of scoring, wear, or damage.
7. Inspect the crankshaft journals for grooves or scoring (2).
8. Inspect the crankshaft journals for scratches or wear (3).
9. Inspect the crankshaft journals for pitting or imbedded bearing material (4).
10. Measure the crankshaft journals (1) for out-of-round.
11. Measure the crankshaft journals for taper.
12. Measure the crankshaft runout. Using wooden V-blocks, support the crankshaft on the front and rear journals.
13. Use the GE-7872 indicator (1) in order to measure the crankshaft runout at the front and rear intermediate journals.
14. Use the GE-7872 indicator in order to measure the runout of the crankshaft rear flange.
15. Replace the crankshaft if the measurements are not within specifications.
16. Inspect crankshaft bearings for craters or pockets (1). Flattened sections on the bearing halves also indicate fatigue.
17. Inspect the crankshaft bearings for excessive scoring or discoloration (2).
18. Inspect the crankshaft bearings for dirt or debris imbedded into the bearing material.
19. Inspect the crankshaft bearings for improper seating indicated by bright, polished sections of the bearing (3). If the lower half of the bearing is worn or damaged, both upper and lower halves should be replaced. Generally, if the lower half is suitable for use, the upper half should also be suitable for use.

Piston and Connecting Rod Disassemble

Special Tools

EN-46745 Piston Pin Retainer Remover and Installer

For equivalent regional tools, refer to Special Tools .

1. Disassemble the piston rings (1, 2, 3, 4, 5). Use a suitable tool to expand the rings. The piston rings must not be reused.
2. Remove the piston pin retainers using the EN-46745 remover (1).
3. Remove the piston pin (1) and the connecting rod (3) from the piston (2).

Connecting Rod Measurement

1. Clean the connecting rods (1) in solvent and dry with compressed air.
2. Inspect the connecting rods for the following: Signs of being twisted, bent, nicked, or cracked Scratches or abrasion on the rod bearing seating surface
3. If the connecting rod bores contain minor scratches or abrasions, clean the bores in a circular direction with a light emery paper. DO NOT scrape the rod or rod cap.
4. If the beam of the rod is scratched or has other damage replace the connecting rod.
5. Measure the piston pin to connecting rod bore using the following procedure: Using an outside micrometer, take two measurements of the piston pin in the area of the connecting rod contact. Using an inside micrometer, measure the connecting rod piston pin bore. Subtract the piston pin diameter from the piston pin bore diameter. The clearance should not be more than 0.021 mm (0.0008 in).
6. If there is excessive clearance, replace the piston pin.
7. If there is still excessive clearance, replace the connecting rod.

Piston Measurement

1. Clean the piston skirts and the pins with a cleaning solvent. DO NOT wire brush any part of the piston.
2. Clean the piston ring grooves with a groove cleaner. Make sure oil ring holes and slots are clean.
3. Inspect the pistons for the following conditions: Cracked ring lands, skirts, or pin bosses Ring grooves for nicks, burrs that may cause binding Warped or worn ring lands Eroded areas at the top of the piston (1) Scuffed or damaged skirts (2) Worn piston pin bores (3)
4. Replace pistons that show any signs or damage or excessive wear.
5. Measure the piston pin bore to piston pin clearances using the following procedure: Piston pin bores and pins must be free of varnish or scuffing. Use an outside micrometer to measure the piston pin in the piston contact areas. Using an inside micrometer, measure the piston pin bore. Subtract the measurement of the piston pin bore from the piston pin. The clearance should be within 0.002-0.012 mm (0.00007-0.00047 in). If the clearance is excessive, determine which component is out of specification.
6. Measure the piston ring end gap using the following procedure: Place the piston ring in the area of the bore where the piston ring will travel (approximately 25 mm or 1 inch down from the deck surface). Be sure the ring is square with the cylinder bore by positioning the ring with the piston head. Measure the end gap of the piston ring with feeler gauges (1). Compare the measurements with those provided below: The top compression ring end gap should be 0.20-0.40 mm (0.0060-0.015 in). The second compression ring end gap should be 0.35-0.55 mm (0.0137-0.0216 in). The oil ring end gap should be 0.25-0.76 mm (0.0098-0.029 in). If the clearance exceeds the provided specifications, the piston rings must be replaced. Repeat the procedure for all the piston rings.
7. Measure the piston ring side clearance using the following procedure: Roll the piston ring entirely around the piston ring groove. If any binding is caused by a distorted piston ring, replace the ring. With the piston ring on the piston, use feeler gauges (1) to check clearance at multiple locations. The clearance between the surface of the top piston ring and the ring land should be no greater than 0.075 mm (0.0030 in). If the clearance is greater than specifications, replace the piston ring. If the new ring does not reduce the top ring side clearance to 0.075 mm (0.0030 in) or less, install a new piston.
8. The top compression ring may be installed with either side up. There is a locating dimple on the 2nd compression ring near the end for identification of the top side. Install the 2nd compression ring with the dimple facing up.
9. The clearance between the surface of the second piston ring and the ring land should be no greater than 0.069 mm (0.0026 in).
10. If the new ring does not reduce the clearance to 0.069 mm (0.0026 in) or less, install a new piston.
11. Measure piston width using the following procedure: Using an outside micrometer (2), measure the width of the piston 14.5 mm (0.570 in) above the bottom of the piston skirt at the thrust surface perpendicular to the centerline of the piston pin. Compare the measurement of the piston to its original cylinder by subtracting the piston width from the cylinder diameter. The proper clearance specification for the piston is 0.010-0.041 mm (0.0006-0.0016 in).
12. If the clearance obtained through measurement is greater than these specifications and the cylinder bores are within specification, replace the piston (1).

Piston Selection

1. Inspect the engine block cylinder bore. Refer to «Engine Block Cleaning and Inspection»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-block-cleaning-and-inspection) .
2. Inspect the piston and the piston pin.
3. Use a bore gauge (1) and measure the cylinder bore diameter. Measure at a point 64 mm (2.5 in) from the top of the cylinder bore.
4. Measure the bore gauge with a micrometer (1) and record the reading.
5. With a micrometer (2) or caliper at a right angle to the piston (1), measure the piston 14 mm (0.570 in) from the bottom of the skirt.
6. Subtract the piston diameter from the cylinder bore diameter in order to determine piston-to-bore clearance.
7. For proper piston-to-bore clearance. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
8. If the proper clearance cannot be obtained, select another piston and measure for the clearances.
9. If the proper fit cannot be obtained, hone the cylinder bore or replace the cylinder block.
10. When the piston-to-cylinder bore clearance is within specifications, mark the top of the piston using a permanent marker for installation to the proper cylinder. Refer to «Separating Parts»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__separating-parts) .

Piston and Connecting Rod Assemble

Special Tools

EN-46745 Piston Pin Retainer Remover and Installer

For equivalent regional tools, refer to Special Tools .

1. The cast boss (1), on the underside of the piston, must go to the rear of the block.
2. The larger feature (1), at the split line located on one side of the connecting rod, must go to the front of the block.
3. Assemble the connecting rod (2) and the piston (1).
4. Use the following procedure to assemble the piston pin and the retainer: Coat the piston pin with oil. Install one side of one piston pin retainer into the retaining groove using EN-46745 installer. Rotate the retainer until it is fully seated in the groove. Install the connecting rod and the piston pin. Push the piston pin until it bottoms in the previously installed retainer. Install the second piston pin retainer, using EN-46745 installer (1). Ensure that the piston moves freely.
5. Install the following components of the oil control ring assembly (bottom ring): The expander (5) The lower oil control ring (4) The upper control ring (3)
6. Install the lower compression ring (2). Place the manufacturer's mark facing up.
7. Install the upper compression ring (1).

Camshaft Cleaning and Inspection (LUK)

1. Inspect the camshaft journals and lobes for wear or scoring.
2. Inspect the camshaft sprocket alignment notch for damage.
3. Inspect the camshaft cover (1) for damage or loose oil control baffles.
4. Clean the camshaft cover.
5. Wash the camshafts (2, 3) in solvent.
6. Oil the camshafts.
7. Inspect the camshaft cover for cracks or other signs of damage.

Camshaft Timing Chain and Sprocket Cleaning and Inspection

1. Inspect the timing chain guides (1, 4, 6) for cracking or wear.
2. Replace the timing chain guides if wear exceeds 1.12 mm (0.045 in) depth on the chain guide surface.
3. Inspect the timing chain tensioner shoe for wear.
4. Replace the timing chain tensioner shoe if wear exceeds 1.12 mm (0.045 in) depth on the chain guide surface.
5. Inspect the timing chain (2) and actuators (3, 8) for wear.
6. Inspect the camshaft actuator faces for signs of movement.
7. Inspect the camshaft actuator teeth and chain for signs of excessive wear, chipping, or seizure of the timing chain links.
8. Inspect the oil nozzle body (5) for collapse or cracks at the bolt boss. Discard and replace the oil nozzle body if it is damaged.
9. Verify oil nozzle oil flow with compressed air.
10. Inspect the timing chain tensioner (7) for the scoring or free movement.
11. Inspect the timing chain tensioner washer and O-ring for damage. If damaged, replace the timing chain tensioner.

Balance Shaft Cleaning and Inspection

1. Clean the balance shafts (1) in solvent.
2. Inspect the bearing surfaces on the balance shafts for scoring or unusual wear.
3. Inspect the balance shaft drive sprockets for wear, damage, or missing teeth.
4. Measure the rear bearing journals on the balance shafts, the journals should be 36.723-36.743 mm (1.4458-1.4466 in) in diameter.
5. Measure the front bearing journals on the balance shafts, the front bearing journals should be 20.020-20.000 mm (0.7881-0.7874 in) in diameter.
6. When the balance shafts have been installed in the engine block, check for smooth rotation, sticking, binding, or roughness.

Water Pump and Balance Shaft Chain and Sprocket Cleaning and Inspection

1. Inspect the balance shaft drive chain guides (3, 5, 8) for cracking or wear.
2. Replace the balance shaft drive chain guides if wear exceeds 1.12 mm (0.045 in) depth on the chain guide surface.
3. Inspect the balance shaft drive chain tensioner guide shoe for wear. Replace the balance shaft drive chain tensioner guide shoe if wear exceeds 1.12 mm (0.045 in) depth on the chain guide surface.
4. Inspect the balance shaft drive chain (7) and sprockets (2, 4) for wear.
5. Inspect the crankshaft sprocket (6) faces for signs of movement.
6. Inspect the alignment notch in the balance shaft for cracking or damage.
7. Inspect the water pump (1), crankshaft, and balance shaft sprocket teeth and chain for signs of excessive wear, chipping, or seizure of the balance shaft drive chain links.
8. Inspect the timing chain tensioner (9) for damage or wear.

Cylinder Head Disassemble (LUK)

Special Tools

1. EN-8062 Valve Spring Compressor
2. EN-36017 Valve Seal Remover
3. EN-43963 Valve Spring Compressor (off car)

For equivalent regional tools, refer to Special Tools .

1. Remove the coolant air bleed hose fitting (1).
2. Remove the intake camshaft position sensor (1) and bolt.
3. Perform the following procedure to remove the valve keys, springs, and retainers: Using the EN-8062 compressor and the EN-43963 compressor, compress the valve spring. Remove the valve keys. Slowly release the EN-8062 compressor and the EN-43963 compressor from the valve spring assembly. Remove the retainer.
4. Remove the springs.
5. Using EN-36017 remover, remove the valve seals. Discard the seals, do not reuse.
6. Remove the valves.
7. Remove the cylinder head plugs.

Cylinder Head Cleaning and Inspection (LUK)

Special Tools

1. EN 22738-B Valve Spring Tester
2. EN-28410 Gasket Remover
3. GE 7872 Magnetic Base Dial Indicator

For equivalent regional tools, refer to Special Tools .

Valve Cleaning and Inspection

1. Clean the valves of carbon, oil and varnish. Use a soft bristle wire brush to clean any carbon build-up from the valve head. Varnish can be removed by soaking in Parts Immersion Solvent. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
2. Clean the valve guides.
3. Inspect the valve stem for pitting or wear (4).
4. Inspect the valve key groove for chipping or wear (5). Replace the valve if chipped or worn.
5. Inspect the valve face for burning or cracking (1). If pieces are broken off, inspect the corresponding piston and cylinder head area for damage.
6. Inspect the valve stem for burrs and scratches. Burrs and minor scratches may be removed with an oil stone.
7. Inspect the valve stem for straightness (3) and the valve head for bending or distortion using V blocks. Bent or distorted valves must be replaced.
8. Clean the deposits from the valve face. Inspect the valve face for grooving.
9. Replace the valve if the face is grooved. Valve faces cannot be machined. If worn, or damaged, the valves must be replaced.
10. Replace the valve if the valve head O.D. and chamfer (2) is worn or out of specification. Refer to «Valve and Seat Grinding»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
11. The valves may be lightly lapped to the valve seats.
12. Replace the valve if the valve tip (6) is worn.
13. If no apparent wear, pitting, grooving, or distortion is present, perform the valve measurement and reconditioning procedure to verify valve specification. Refer to «Valve and Seat Grinding»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .

Valve Guide Measurement

1. Measure the valve stem (1)-to-guide (2) clearance. Excessive valve stem-to-guide clearance may cause an excessive oil consumption and may also cause a valve to break. Insufficient clearance will result in noisy and sticky functioning of the valve and will disturb the engine assembly smoothness.
2. Clamp the GE 7872 dial indicator to the cylinder head at the camshaft cover rail.
3. Locate the dial indicator so that the movement of the valve stem from side to side, crossways to the cylinder head, will cause a direct movement of the indicator stem. The dial indicator stem must contact the side of the valve stem just above the valve guide.
4. Drop the valve head about 0.064 mm (0.0025 in) off the valve seat.
5. Use light pressure when moving the valve stem from side to side in order to obtain a clearance reading. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) for proper clearance.
6. If the clearance for the valve is greater than specifications and a new standard diameter valve stem will not bring the clearance within specifications, replace the cylinder head.

Valve Spring Cleaning and Inspection

1. Clean the valve springs in solvent.
2. Dry the valve springs with compressed air.
3. Inspect the valve springs for broken coils or coil ends.
4. Measure the valve spring tension using the EN 22738-B tester. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk)
5. If low valve spring load is found, replace the valve springs. DO NOT use shims to increase spring load. The use of shims can cause the valve spring to bottom out before the camshaft lobe is at peak lift.

Valve Rocker Arm Cleaning and Inspection

1. Inspect the camshaft follower roller (1) for the following: Flat spots Excessive scoring and pitting Ensure the roller spins freely
2. Inspect the camshaft follower valve tip area (2).
3. Inspect the camshaft follower stationary hydraulic lash adjuster (SHLA) pivot area (3).
4. Replace the camshaft follower or followers as necessary.

Cylinder Head and Gasket Surface Cleaning and Inspection

1. Remove the spark plugs.
2. Inspect the cylinder head gasket and mating surfaces for leaks, corrosion and blow-by. If the gasket has failed, use the following faults to determine the cause: Improper installation Loose or warped cylinder head Missing, off location or not fully seated dowel pins Corrosion in the seal area around the coolant passages Chips or debris in the cylinder head bolt holes Bolt holes in the cylinder block not drilled or tapped deep enough
3. Inspect the cylinder head gasket surface. Cylinder head may be reused if corrosion is found only outside a 4 mm (0.375 in) band around each combustion chamber (1). Replace the cylinder head if the area between the valve seats is cracked (2). Replace the cylinder head if corrosion has been found inside a 4 mm (0.375 in) band around each combustion chamber (3).
4. Clean the cylinder head bolts.
5. Remove the sealant from the rear cap mating surface with EN-28410 remover. Care must be used to avoid gouging or scraping the sealing surfaces.
6. Clean the cylinder head. Remove all varnish, soot and carbon to the bare metal.
7. Clean the valve guides.
8. Clean the threaded holes. Use a nylon bristle brush.
9. Clean the remains of the sealer from the plug holes.
10. Inspect the cylinder head bolts for damaged threads or stretching and damaged heads caused by improper use of tools.
11. Replace all suspect bolts.
12. Inspect the cylinder head for cracks. Check between the valve seats and in the exhaust ports.
13. Inspect the cylinder head deck for corrosion, sand inclusions and blow holes.
14. Using a straight edge (1) and feeler gauge (2), inspect the cylinder head deck surface for flatness. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) . If the cylinder head is out of specification, replace the cylinder head. Do not machine the cylinder head.
15. Inspect all the threaded holes for damage. Threads may be reconditioned with thread inserts.
16. Inspect the sealing surfaces.
17. Inspect the cylinder head plugs and verify the oil orifice is clear and free of debris.
18. Clean the sealant from the rear cap mating surface with EN-28410 remover. Care must be used to avoid gouging or scraping the sealing surfaces.
19. Inspect the intake camshaft bearing rear cap (1) for damage.
20. Inspect the rear bearing mating surfaces for damage.
21. Inspect the camshaft bearing caps (2) for damage.
22. Inspect the camshaft front bearing caps (3) for damage.
23. Install the spark plugs. Tighten the plugs to 20 N.m (15 lb ft).

Valve Measurement and Reconditioning Overview

1. Proper valve service is critical to engine performance. Therefore, all detailed measurement procedures must be followed to identify components that are out of specification.
2. If the measurement procedures reveal that the valve or valve seat must be reconditioned, it is critical to perform the measurement procedures after reconditioning.

Valve Seat Width Measurement Procedure

1. Measure the valve seat width in the cylinder head using a proper scale.
2. Measure the seat width (b) on the valve face (1) using a proper scale.
3. Compare your measurements with the specifications listed in «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
4. If the seat widths are acceptable, check the valve seat roundness using the Valve Seat Roundness Measurement Procedure.
5. If the seat width is not acceptable, you must grind the valve seat using the Valve and Seat Reconditioning Procedure to bring the width back into specification. Proper valve seat width is critical to providing the correct amount of valve heat dissipation.

Valve Seat Roundness Measurement Procedure

1. Measure the valve seat roundness using a dial indicator attached to a tapered pilot installed in the guide. The pilot should have a slight bind when installed in the guide.
2. Compare your measurements with the specifications listed in «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
3. If the valve seat exceeds the roundness specification, you must grind the valve and valve seat using the Valve and Seat Reconditioning Procedure.
4. If new valves are being used, the valve seat roundness must be within 0.05 mm (0.002 in).

Valve Head O.D. and Chamfer Measurement Procedure

1. Measure the valve head O.D. and chamfer (a) using an appropriate scale. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
2. If the valve head O.D. and chamfer is within specification, test the valve (1) for seat concentricity using the Valve-to-Seat Concentricity Measurement Procedure. Reinspect the valve head O.D. and chamfer after completing the concentricity measurement if valve seat reconditioning is performed.

Valve-to-Seat Concentricity Measurement Procedure

1. Coat the valve face (3) lightly with blue dye (1).
2. Install the valve in the cylinder head.
3. Turn the valve against the seat with enough pressure to wear off the dye.
4. Remove the valve from the cylinder head.
5. Inspect the valve face. If the valve face is concentric, providing a proper seal, with the valve stem, a continuous mark (2) will be made around the entire face. NOTE: The wear mark MUST be at least 0.5 mm (0.020 in) from the outer diameter, the margin (a), of the valve. If the wear mark is too close to the margin, the seat must be reconditioned to move the contact area away from the margin. NOTE: Do not grind or condition the intake valve. If the intake valve is out of specification, replace the valve. If the face is not concentric with the stem, the mark will NOT be continuous around the valve face. The valve should be refaced or replaced and the seat must be reconditioned using the Valve and Seat Reconditioning Procedure.

Valve and Seat Reconditioning Procedure

1. Grind the valve seating surface (a) to the proper angle specification (2) listed in «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
2. Grind the valve relief surface to the proper angle specification (1) listed in «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) , to correctly position the valve seating surface (a) to the valve.
3. Grind the valve undercut surface to the proper angle specification (3) listed in «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) ,, to narrow the valve seating surface width (a) to the specifications listed in «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
4. Replace the intake valve if it is out of specification. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
5. If the original exhaust valve is being used, grind the valve to the specifications listed in «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) . Measure the valve head O.D. and chamfer again after grinding using the Valve Head O.D. and Chamfer Measurement Procedure. Replace the exhaust valve if it is out of specification. New valves do not require grinding.
6. When grinding the valves and seats, grind off as little material as possible. Cutting valve seat results in lowering the valve spring pressure.
7. Install the valve in the cylinder head. If you are using refaced exhaust valves, lap the valves into the seats with a fine grinding compound. The refacing and reseating operations should leave the refinished surfaces smooth and true so that minimal lapping is required. Excessive lapping will groove the valve face and prevent a good seat when hot. Be sure to clean any remaining lapping compound from the valve and seat with solvent and compressed air prior to final assembly.
8. After obtaining the proper valve seat width in the cylinder head, you must re-measure the valve stem height using the Valve Stem Height Measurement Procedure.
9. If the valve stem height is acceptable, test the seats for concentricity using the Valve-to-Seat Concentricity Measurement Procedure.

Valve Stem Height Measurement Procedure

1. Install the valve (1) into the valve guide in the cylinder head (2).
2. Ensure the valve is seated to the cylinder head valve seat.
3. Install the valve stem oil seal.
4. Install the valve spring retainer and valve stem locks.
5. Measure the distance (a) between the valve seal lip to the bottom of the valve spring retainer. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) .
6. If the maximum height specification is exceeded, a new valve should be installed and the valve stem height re-measured.
7. If the valve stem height still exceeds the maximum height specification, the cylinder head must be replaced.

Cylinder Head Assemble (LUK)

Special Tools

1. EN-8062 Valve Spring Compressor
2. EN-9666 Valve Spring Tester
3. EN-43963 Valve Spring Compressor (off car)

For equivalent regional tools, refer to Special Tools .

1. Install NEW cylinder head plugs. Coat the plugs with sealer. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
2. Inspect the valve springs for the following conditions: Expanded height Unparallel spring ends Spring tension using EN-9666 tester Any distorted springs should be replaced
3. Inspect the valves and the valve seats. Refer to «Valve and Seat Grinding»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
4. Install the valves (1). Replace the valves, if required.
5. Install the NEW valve seals (1). Fully seat the seals on the valve guides.
6. Install the springs (1).
7. Install the retainers and keys using the following procedure: Install the retainer (2). Using the EN-8062 compressor and the EN-43963 compressor, compress the valve spring. Install the valve keys (1). Slowly release the EN-8062 compressor and the EN-43963 compressor (off car) from the valve/spring assembly. Inspect for proper valve key seating.
8. Lubricate the camshaft position sensor O-ring with clean engine oil.
9. Install the intake camshaft position sensor (1) and bolt. Tighten the bolt to 10 N.m (89 lb in).
10. Install the cylinder head air bleed tube (1) and tighten the tube to 15 N.m (11 lb ft).

Oil Pump Disassemble

1. Remove the pressure relief plug (1), spring (2), and plunger (3).
2. Remove the oil pump gerotor cover (1) and bolts.
3. Clean all of the parts in cleaning solvent. Remove varnish, sludge and dirt.
4. Inspect the oil pump (2, 3) for wear and scoring. Ensure that all components are within specifications. Refer to «Engine Mechanical Specifications (LUK)»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__engine-mechanical-specifications-luk) . Replace the front cover (4) and oil pump assembly if it is out of specification or damaged.

Oil Pump Assemble

1. Lubricate all oil pump parts with engine oil.
2. Install the inner gear (2) into the outer gear (3).
3. Install the gears together into the front cover (4) with the hub of the center gear facing the front cover.
4. Install the oil pump gerotor cover (1) and bolts and tighten to 6 N.m (53 lb in).
5. Install the pressure relief valve plunger (3).
6. Install the pressure relief valve spring (2).
7. Install and tighten the pressure relief valve plug (1) to 40 N.m (30 lb ft).

Fuel Rail and Injectors Cleaning and Inspection (LUK)

Special Tools

1. EN-49245 Fuel Injector Seal Installer and Sizer
2. EN-49247 Injector Retaining Clip Installer

For equivalent regional tools, refer to Special Tools .

1. Disconnect the electrical connections from the fuel injectors (1).
2. Remove and discard the fuel injector retainer (2).
3. Remove the injectors (1) from the fuel rail by pulling straight out along the fuel injector axis. Slight rotation of the fuel injector is acceptable.
4. Using a suitable tool, remove the fuel injector bushing (1) by pushing straight off at the bushing tabs, indicated by the arrows. Discard the bushing.
5. Remove and discard the fuel injector O-ring (3) and plastic spacers (2).
6. Remove and discard the fuel injector seals (1).
7. Clean the exterior of the fuel rail (1) and injectors in solvent.
8. Inspect the fuel rail and components for the following conditions: Damage, debris, or restrictions to the fuel rail Damage, debris, or restrictions to the fuel ports in the fuel rail Damage to the mounting area for the fuel rail Damage to the fuel rail mounting bolts Damage to the threads on the fuel rail fuel feed fitting
9. Replace the fuel rail if any damage is found. Do not attempt to repair a fuel rail.
10. Inspect the fuel pressure sensor (3) for damage. Disconnect the harness connector (2) from the fuel pressure sensor. Remove the fuel pressure sensor. Dry the fuel pressure sensor bore in the fuel rail with a lint free cloth. The bore should be free of fuel, debris, and burrs. Lubricate the fuel rail fuel pressure sensor bore with clean engine oil. Lubricate the threads and sealing area on the fuel pressure sensor with clean engine oil. Install the fuel pressure sensor hand tight. Remove the fuel pressure sensor and re-lubricate the bore, threads, and sealing area. Install the fuel pressure sensor and tighten to 33 N.m (25 lb ft). Connect the harness connector to the fuel pressure sensor.
11. Inspect the fuel injectors for the following conditions: Damage to the fuel injector connector (7) Damage to the fuel injector harness connector Damage to the fuel injector tip (1) Damage to the tolerance ring (2)
12. Replace the fuel injector if any damage is found. Do not attempt to repair a fuel injector.
13. Install a new fuel injector bushing (3) onto the fuel injector. The bushing should seat with a distinct "snap" sound and feel.
14. Install the new white plastic spacer (4) on the fuel injector first.
15. Install the new brown plastic spacer (5) second.
16. Lubricate the new O-ring (6) with 5W30 engine oil.
17. Install the O-ring on the injector.
18. Install the fuel injectors (1) into the fuel rail. Ensure the fuel injector is fully seated in the fuel rail, and no gaps are present (2). Ensure the injector and fuel rail flanges are aligned (3)
19. Install the fuel injector retainer onto the EN-49247 installer.
20. Using EN-49247 installer, install the fuel injector retainer.
21. Inspect each installed fuel injector retainer, and ensure the retainer is fully seated on the fuel rail and fuel injector bushing flanges (1). The flanges on each side and at the top of the fuel injector should seat completely into the window on the retainer.
22. Connect the electrical connection to the fuel rail.
23. Connect the fuel rail harness connectors (1) to the fuel injectors.
24. Install EN-49245-1 long protector (3) onto the fuel injector tip, covering the first recessed area closest to the tip. Place a NEW seal (2) on EN-49245-1 long protector.
25. Using EN-49245-3 pusher (1), install the seal into the second recessed area (4) of the fuel injector.
26. Compress the seal with your fingers, then resize the seal using the EN-49245-4 sizer (5).
27. Install EN-49245-2 short protector (3) onto the fuel injector tip. Place a NEW seal (2) on EN-49245-2 short protector.
28. Using EN-49245-3 pusher (1), install the seal into the first recessed area (4) of the fuel injector.
29. Compress the seal with your fingers, then resize the seal using the EN-49245-4 sizer (5).

Intake Manifold Cleaning and Inspection (LUK)

1. Clean the intake manifold (1) mating surfaces.
2. Inspect the intake manifold for damage.
3. Inspect the intake manifold for cracks near metallic inserts.
4. Clean and inspect the intake manifold insulator (2) for damage.
5. Inspect the crankcase ventilation passages (1) in the intake manifold face for blockage.
6. Clean the crankcase ventilation passages with compressed air if necessary. Use a maximum of 172 kPa (25 psi) of air pressure.
7. Replace the intake manifold as necessary.

Exhaust Manifold Cleaning and Inspection (LUK)

1. Remove the oxygen sensor (3) from the manifold.
2. Clean the exhaust manifold (2) in solvent.
3. Dry the exhaust manifold with compressed air.
4. Inspect the heat shield (1) for damage.
5. Use a straight edge and a feeler gauge and measure the exhaust manifold mounting face (1) for warpage. An exhaust manifold face with warpage in excess of 0.25 mm (0.0100 in) may cause an exhaust leak and may effect OBD II system performance. Exhaust manifolds not within specifications must be replaced.

Oil Pan Cleaning and Inspection

1. Clean the oil pan mating surface.
2. Clean the oil pan (1). Remove all the sludge and the oil deposits.
3. Inspect the threads for the engine oil drain plug.
4. Inspect the oil pan for cracking near the pan rail and the transmission mounting points.
5. Inspect the oil pan for cracking resulting from impact or flying road debris.
6. Inspect the oil pan baffle and pickup screen.
7. Repair or replace the oil pan as necessary.

Thread Repair

Special Tools

EN 42385-850 Thread Repair Kit

For equivalent regional tools, refer to Special Tools .

Scheme 31

The thread repair process involves a solid, thin walled, self-locking, carbon steel, bushing type insert (1). During the bushing installation process, the driver tool expands the bottom external threads of the insert into the base material (2). This action mechanically locks the insert in place. Also, when installed to the proper depth, the flange of the insert will be seated against the counterbore of the repaired hole.

1. Drill out the threads of the damaged hole (1). M6 inserts require a minimum drill depth of 15 mm (0.59 in). M8 inserts require a minimum drill depth of 20 mm (0.79 in). M10 inserts require a minimum drill depth of 23.5 mm (0.93 in).
2. Using compressed air, clean out any chips.
3. Counterbore the hole to the full depth permitted by the tool (1).
4. Using compressed air, clean out any chips.
5. Using a tap wrench (2), tap the threads of the drilled hole. M6 inserts require a minimum tap depth of 15 mm (0.59 in). M8 inserts require a minimum tap depth of 20 mm (0.79 in). M10 inserts require a minimum tap depth of 23.5 mm (0.93 in).
6. Using compressed air, clean out any chips.
7. Spray cleaner into the hole. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
8. Using compressed air, clean any cutting oil and chips out of the hole.
9. Lubricate the threads of the installer tool (2) with the driver oil (1).
10. Install the insert (2) onto the driver tool (1).
11. Apply threadlock LOCTITE™ 277, EN 42385-109 (1) loctite, or equivalent to the insert OD threads (2).
12. Install the insert (2) into the hole. Install the insert until the flange of the insert contacts the counterbored surface. Continue to rotate the installer tool (1) through the insert. The installer tool will tighten up before screwing completely through the insert. This is acceptable. You are forming the bottom threads of the insert and mechanically locking the insert to the base material threads.
13. Inspect the insert for proper installation into the hole. A properly installed insert (1) will be either flush or slightly below flush with the surface of the base material (2).

Cylinder Head Bolt Hole Thread Repair

1. The cylinder head bolt hole thread repair kit consists of the following items: Drill (1) Tap (2) Installer (3) Sleeve (4) Alignment Pin (5) Bushing (6) Bolts (7) Fixture Plate (8)
2. Install the fixture plate (3), bolts (1), and bushing (2) onto the engine block deck. Position the fixture plate and bushing over the hole that is to be repaired (4).
3. Position the alignment pin (1) through the bushing and into the hole.
4. With the alignment pin in the desired hole, tighten the fixture retaining bolts (2).
5. Remove the alignment pin from the hole.
6. Install the sleeve (2) onto the drill (1), if required.
7. Drill out the threads of the damaged hole. Drill the hole until the stop collar of the drill bit or the sleeve contacts the bushing.
8. Using compressed air, clean out any chips.
9. Using a tap wrench, tap the threads of the drilled hole.
10. Using a TAP wrench, tap the threads of the drilled hole. In order to tap the new threads to the proper depth, rotate the tap into the hole until the mark (3) on the tap align with the top of the drill bushing (2).
11. Remove the fixture plate (1), bushing (2), and bolts.
12. Using compressed air, clean out any chips.
13. Spray cleaner into the hole. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
14. Using compressed air, clean any cutting oil and chips out of the hole.
15. Lubricate the threads of the installer tool (2) with the driver oil (1).
16. Install the insert (2) onto the driver tool (1).
17. Apply threadlock LOCTITE™ 277, EN 42385-109 loctite (1), or equivalent to the insert OD threads (2).
18. Install the insert and driver (1) into the hole. Rotate the driver tool until the mark on the tool aligns with the deck surface of the engine block. The installer tool will tighten up before screwing completely through the insert. This is acceptable. You are forming the bottom threads of the insert and mechanically locking the insert to the base material threads.

Main Cap Bolt Hole Thread Repair

1. The main cap bolt hole thread repair kit consists of the following items: Drill (1) Tap (2) Installer (3) Fixture Plate (4) Long Bolts (5) Short Bolts (6) Alignment Pin (7) Bushing (8)
2. Remove the alignment dowel pins from the holes (1-4), if necessary.
3. Install the fixture plate, bolt, and bushing, onto the engine block. Position the fixture plate and bushing over the hole that is to be repaired.
4. Position the alignment pin in the desired hole and tighten the fixture retaining bolts.
5. Drill out the damaged hole.
6. Using compressed air, clean out any chips.
7. Using a tap wrench, tap the threads of the drilled hole. In order to tap the new threads to the proper depth, rotate the tap into the hole until the mark (3) on the tap aligns with the top of the bushing (2).
8. Using compressed air, clean out any chips.
9. Spray cleaner into the hole. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
10. Using compressed air, clean any cutting oil and chips out of the hole.
11. Lubricate the threads of the installer tool (2) with the driver oil (1).
12. Install the insert (2) onto the driver tool (1).
13. Apply threadlock LOCTITE™ 277, EN 42385-109 (1), or equivalent to the insert OD threads (2).
14. Install the insert and driver through the bushing (2), fixture plate (1) and into the hole. Rotate the driver tool until the mark on the tool (3) aligns with the top of the bushing (2). The installer tool will tighten up before screwing completely through the insert. This is acceptable. You are forming the bottom threads of the insert and mechanically locking the insert to the base material threads.
15. Remove the driver, bushing (2), fixture plate (1), and bolts.
16. Install the alignment dowel pins in holes (1-4), if necessary.

Service Prior to Assembly

The importance of cleanliness during assembly cannot be overstated. Dirt or debris will cause engine damage. An automobile engine is a combination of many machined, honed, polished and lapped surfaces with tolerances that are measured in ten thousandths of an inch. When any internal engine parts are serviced, care and cleanliness are important. A liberal coating of engine oil should be applied to friction areas during assembly in order to protect and lubricate the surfaces on initial operation. Throughout this section, it should be understood that proper cleaning and protection of machined surfaces and friction areas are part of the repair procedure. This is considered standard shop practice even if not specifically stated.

Lubricate all moving parts with engine oil or a specified assembly lubricant. This will provide lubrication for initial start up.

Engine Block Assemble

1. Apply sealant to all plugs (1, 2, 3) prior to installation. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
2. Install the drain plug, with sealant, in the water pump.
3. Install the coolant jacket plugs, with sealant, and tighten to 35 N.m (26 lb ft).
4. Install the rear oil passage plugs, with sealant, and tighten to 60 N.m (44 lb ft).
5. Install the other oil passage plugs, with sealant, and tighten to 35 N.m (26 lb ft).
6. Lubricate the crankshaft position sensor O-ring with engine oil. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
7. Install the crankshaft position sensor (1) and bolt and tighten to 10 N.m (89 lb in).
8. Install the oil pressure switch (2) and tighten to 26 N.m (19 lb ft).
9. Install the knock sensor (1) and bolt and tighten to 25 N.m (18 lb ft).
10. Install the piston oil nozzle assemblies (1), if equipped.
11. Install the piston oil nozzle assembly bolts and tighten to 15 N.m (11 lb ft).

Crankshaft and Bearing Installation

Special Tools

1. EN-8087 Cylinder Bore Checking Gauge
2. EN 45059 Angle Meter

For equivalent regional tools, refer to Special Tools .

Scheme 32

Note. Crankshaft bearings MUST be separated, marked, or organized in a way to ensure installation to their original location and position, when suitable for use. If crankshaft bearing failure is due to other than normal wear, investigate the cause. Inspect the crankshaft or connecting rod bearing bores.

Inspect the connecting rod bearing bores or crankshaft main bearing bores using the following procedure

1. Tighten the bedplate to specification using the EN 45059 meter.
2. Measure the bearing bore for taper and out-of-round using the EN-8087 gauge (1).
3. No taper or out-of-round should exist.

Bearing Selection

1. Measure the bearing clearance to determine the correct replacement bearing insert size. There are 2 methods to measure bearing clearance. Method A gives more reliable results and is preferred. Method A yields measurement from which the bearing clearance can be computed. Method B yields the bearing clearance directly. Method B does not give any indication of bearing run-out.
2. To measure bearing clearance using Method A, use the following procedure: Measure the crankshaft bearing journal diameter with a micrometer (1) in several places, 90 degrees apart. Average the measurements. Measure the crankshaft bearing journal taper and runout. Install the lower crankcase and tighten the bearing cap bolts to specification. Measure bearing inside diameter (ID) in several places 90 degrees apart, average measurements. Subtract journal measurement from bearing ID measurement to determine clearance. Determine whether clearance is within specification. If out of specification, choose different inserts. Measure the connecting rod inside diameter in the same direction as the length of the rod with an inside micrometer. Measure the crankshaft main bearing inside diameter with an inside micrometer.
3. To measure bearing clearance using Method B, use the following procedure: Clean the used bearing inserts. Install the used bearing inserts. Place a piece of gaging plastic across the entire bearing width. Install the bearing caps. CAUTION: In order to prevent the possibility of cylinder block or crankshaft bearing cap damage, the crankshaft bearing caps are tapped into the cylinder block cavity using a brass, lead, or a leather mallet before the attaching bolts are installed. Do not use attaching bolts to pull the crankshaft bearing caps into the seats. Failure to use this process may damage a cylinder block or a bearing cap. Install the bearing cap bolts to specification. NOTE: Do not rotate the crankshaft. Remove the bearing cap, leaving the gauging plastic in place. It does not matter whether the gauging plastic adheres to the journal or to the bearing cap. Measure the gauging plastic at its widest point with the scale (1) printed on the gauging plastic package. Remove the gauging plastic.

Lower Crankcase Installation

Special Tools

EN 45059 Angle Meter

For equivalent regional tools, refer to Special Tools .

1. Install the upper crankshaft bearings (1) and lubricate bearing surfaces with engine oil.
2. Install the crankshaft (1) on the journals.
3. Install the lower bearing halves (1), without grooves, into the lower crankcase. Apply oil to bearing surfaces.
4. Apply a 4.25 mm bead of sealer, dimension (a), directly in the groove of the block to bedplate mating surfaces. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
5. Install the lower crankcase (1). Tap gently into place with a suitable tool if necessary. Ensure it is aligned properly on the dowels.
6. Install the NEW crankshaft bearing bolts in sequence finger tight. Tighten the crankshaft bearing bolts in sequence to 20 N.m (15 lb ft). Tighten the crankshaft bearing bolts in sequence using the EN 45059 meter an additional 70 degrees.
7. Tighten the lower crankcase perimeter bolts in sequence to 25 N.m (18 lb ft).

EN-42067 Rear Main Seal Installer

For equivalent regional tools, refer to Special Tools .

1. Remove excess sealer from seal recess.
2. Lubricate the outside diameter of the new crankshaft seal with clean engine oil.
3. Using the EN-42067 installer (1), press the new crankshaft seal into the housing. The EN-42067 installer also establishes the depth of the seal in the crankshaft seal bore.

Piston, Connecting Rod, and Bearing Installation (LAF, LAT, LE5, LE9, LEA, or LUK)

Note. This procedure is not used in Europe.

Special Tools

1. EN-43966 Connecting Rod Guides
2. EN 45059 Angle Meter
3. EN-47836 Piston Ring Compressor

For equivalent regional tools, refer to Special Tools .

1. Install the connecting rod bearings. Use NEW bearings. Install the bearing inserts into the connecting rod and the connecting rod cap. Lubricate the connecting rod bearings with engine oil.
2. Install the EN-43966 guides (1) into the connecting rod bolt holes. This protects the crankshaft journal during piston and connecting rod installation.
3. Install EN-47836 compressor, piston, and the connecting rod to the correct bore. Stagger each piston ring end gap equally around the piston. Lubricate the piston and the piston rings with engine oil. Do not disturb the piston ring end gap location. The piston must be installed so that the mark on the top of the piston faces the front of the engine. Place the piston in its matching bore. Tap the piston into its bore with a hammer handle. Guide the connecting rod to the connecting rod journal while tapping the piston into place. Hold the EN-47836 compressor against the engine block until all the rings have entered the cylinder bore. Remove the connecting rod guides from the connecting rod bolt holes.
4. Install the connecting rod cap (1).
5. Install the connecting rod bolts. Always use new bolts. Tighten the connecting rod bolts to 25 N.m (18 lb ft), plus 100 degrees using the EN 45059 meter.
6. Install the remaining connecting rods and piston assemblies.
7. Measure the connecting rod side clearance with a feeler gauge (1). The correct clearance is 0.07-0.37 mm (0.0027-0.0145 in).

Cylinder Head Installation (LUK)

Special Tools

EN 45059 Angle Meter

For equivalent regional tools, refer to Special Tools

1. Install the cylinder head gasket to the block.
2. Install the cylinder head. Ensure the number 1 cylinder is at top dead center (TDC). The key on the crankshaft should be on top in the 12 o'clock position.
3. Install the cylinder head bolts. Tighten the bolts in sequence to 30 N.m (22 lb ft). Tighten the bolts an additional 155 degrees in sequence using the EN 45059 meter.
4. Install the front cylinder head bolts and tighten to 30 N.m (22 lb ft).

Exhaust Camshaft Installation

1. Install the hydraulic lash adjusters into their bores in the cylinder head and lubricate. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
2. Lubricate the valve tips. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
3. Position the roller followers on the tip of the valve stem and on the lash adjuster and lubricate. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
4. When installing the camshafts, ensure the intake camshaft notch is in the 10 o'clock position (2) and the exhaust camshaft notch is in the 7 o'clock position (1). The number 1 piston should be at top dead center (TDC), crankshaft key at 12 o'clock.
5. Set the exhaust camshaft on top of the roller followers in the camshaft bearing journals and lubricate. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
6. Rotate the oil seal in the groove of the number one camshaft journal so the split line (1) is at approximately the 12:00 position before installing the camshaft caps.
7. Install the exhaust camshaft with the notch on the front (1) at approximately the 7 o'clock position.
8. Install the camshaft caps and hand start the camshaft cap bolts.
9. Tighten the camshaft cap bolts in increments of 3 turns until they are seated. Tighten the camshaft caps to 10 N.m (89 lb in).
10. Install the exhaust camshaft position actuator solenoid valve (2). Tighten the solenoid valve bolt (1) to 10 N.m (89 lb in).

Intake Camshaft Installation

1. Install the hydraulic lash adjusters into their bores in the cylinder head.
2. Lubricate the hydraulic lash adjusters. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
3. Lubricate the valve tips. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
4. Position the roller followers on the tip of the valve stem and on the lash adjuster. Lubricate roller followers. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
5. When installing the camshafts, ensure the intake camshaft notch is in the 10 o'clock position (2) and the exhaust camshaft notch is in the 7 o'clock position (1). The number 1 piston should be at top dead center (TDC), crankshaft key at 12 o'clock.
6. Set the intake camshaft on top of the roller followers in the camshaft bearing journals and lubricate. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
7. Rotate the oil seal in the groove of the number one camshaft journal so the split line (1) is at approximately the 12:00 position before installing the camshaft caps.
8. Install the intake camshaft with the notch on the front at approximately the 10 o'clock position (2).
9. Install the camshaft caps and hand start the camshaft cap bolts.
10. Tighten the camshaft cap bolts in increments of 3 turns until they are seated. Tighten the camshaft caps to 10 N.m (89 lb in).
11. Apply a 2.5 mm bead of sealer to the cylinder head at the number 6 intake camshaft rear cap mating surface. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
12. Install the number 6 intake camshaft rear cap. Tighten the cap bolts evenly to 5 N.m (44 lb in). Tighten the cap bolts evenly to 10 N.m (89 lb in). Back the cap bolts out 120 degrees. Tighten the cap bolts evenly a final pass to 10 N.m (89 lb in).
13. Remove all excess sealing material from the fuel pump roller lifter bore (1), and ensure the bore is free of debris. Do not allow any excess sealing material to remain within the cylinder head or on any sealing surface.
14. Remove all excess sealing material from the fuel pump assembly sealing surface (2).
15. Verify the seal on the cylinder head cover plate (1) is intact and in good condition.
16. Ensure that the opening plate sealing surface is clean and free of excess sealing material. Install the rear cylinder head opening plate (1) and tighten the bolts to 10 N.m (89 lb in).
17. Install the intake camshaft position actuator solenoid valve (2). Tighten the solenoid valve bolt (1) to 10 N.m (89 lb in).

Balance Shaft Installation

Note. This procedure is not used in Europe.

Special Tools

EN-43650 Balance Shaft Bushing Remover/Installer

For equivalent regional tools, refer to Special Tools .

1. Install the balance shaft bushing using the EN-43650 installer (1).
2. Seat the balance shaft bushing into the bore using the EN-43650 installer (1) and a wrench.
3. When the EN-43650 installer is fully seated in the engine block, remove it with a wrench.
4. Place the number one piston at top dead center (TDC).
5. Lubricate the balance shaft lobes with engine oil.
6. Install the balance shafts (1) into their bores.
7. Install the balance shaft retaining bolts and tighten to 10 N.m (89 lb in).

Water Pump Installation

Prior to installing the water pump, read the entire procedure. Pay special attention to avoid part damage and to ensure proper sealing.

1. Install the water pump assembly (1).
2. Install the water pump bolts. Finger tighten the bolts.
3. Tighten the water pump bolts to 25 N.m (18 lb ft).
4. Apply sealant to the water pump drain plug. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
5. Install the water pump drain plug, if necessary. Tighten to 20 N.m (15 lb ft).
6. Install the water feed tube (1).
7. Lubricate the feed tube O-ring with antifreeze.
8. Install the water feed tube by twisting and pushing toward the water pump. Take care not to tear or damage the O-ring.
9. Install the thermostat housing (2) to block bolts and stud and tighten to 10 N.m (89 lb in).
10. Install the engine coolant temperature sensor (1) by hand.
11. Tighten the engine coolant temperature sensor and tighten to 20 N.m (15 lb ft).

Balance Shaft to Engine Timing (LUK)

1. Install the balance shaft drive sprocket.
2. Install the balance shaft drive chain with the colored links lined up on with the marks on the balance shaft drive sprockets and the crankshaft sprocket. There are three colored links on the chain. Two links are of matching colors, and one link is of a unique color. Use the following procedure to line up the links with the sprockets: Orient the chain so that the colored links are visible.
3. Place the uniquely colored link (1) so that it lines up with the timing mark on the intake side balance shaft sprocket.
4. Working clockwise around the chain, place the first matching colored link (2) in line with the timing mark on the crankshaft drive sprocket, approximately 6 o'clock position on the crank sprocket.
5. Place the chain (3) on the water pump drive sprocket. The alignment is not critical.
6. Align the last matching colored link (4) with the timing mark on the exhaust side balance shaft drive sprocket.

Water Pump and Balance Shaft Chain and Tensioner Installation

1. Install the upper balance shaft chain guide (1) and bolts and tighten to 12 N.m (106 lb in).
2. Install the small balance shaft chain guide (1).
3. Install the balance shaft chain guide bolts and tighten to 12 N.m (106 lb in).
4. Install the adjustable balance shaft drive chain guide (1).
5. Install the adjustable balance shaft drive chain guide bolts and tighten to 10 N.m (89 lb in).
6. Reset the timing chain tensioner (1) by performing the following steps: Turn the tensioner plunger 90 degrees in its bore and compress the plunger. Turn the tensioner back to the original 12 o'clock position and insert a paper clip through the hole in the plunger body and into the hole in the tensioner plunger.
7. Install the timing chain tensioner.
8. Install the chain tensioner bolts and tighten to 10 N.m (89 lb in).
9. Remove the paper clip from the balance shaft drive chain tensioner.

Camshaft Timing Chain, Sprocket, and Tensioner Installation (LUK)

Special Tools

1. EN-45027 Tensioner Tool
2. EN 45059 Angle Meter
3. EN-48953 Camshaft Actuator Locking Tool

For equivalent regional tools, refer to Special Tools .

1. Ensure the intake camshaft notch is in the 10 o'clock position (2) and the exhaust camshaft notch is in the 7 o'clock position (1). The number 1 piston should be at top dead center (TDC), crankshaft key at 12 o'clock.
2. Install a friction washer (1), if equipped.
3. Install the timing chain drive sprocket (3) to the crankshaft with the timing mark (2) in the 5 o'clock position and the front of the sprocket facing out.
4. Install a second friction washer (1), if equipped.
5. Assemble the intake camshaft actuator into the timing chain with the timing mark lined up with the uniquely colored link (1).
6. Lower the timing chain through the opening in the cylinder head. Use care to ensure that the chain goes around both sides of the cylinder block bosses (1, 2).
7. Install the intake camshaft actuator onto the intake camshaft while aligning the dowel pin into the camshaft slot.
8. Hand tighten the new intake camshaft actuator bolt.
9. Route the timing chain around the crankshaft sprocket and line up the first matching colored link (1) with the timing mark on the crankshaft sprocket, in approximately the 5 o'clock position.
10. Rotate the crankshaft clockwise to remove all chain slack. Do not rotate the intake camshaft.
11. Install the adjustable timing chain guide (1) down through the opening in the cylinder head and install the adjustable timing chain bolt and tighten to 10 N.m (89 lb in).
12. Install the exhaust camshaft actuator (1) into the timing chain with the timing mark lined up with the second matching colored link.
13. Install the exhaust camshaft actuator (1) onto the exhaust camshaft, aligning the dowel pin into the camshaft slot.
14. Using a 23-24 mm open end wrench, rotate the exhaust camshaft clockwise until the dowel pin in the camshaft actuator goes into the camshaft slot.
15. When the actuator (1) seats on the cam, tighten the new exhaust camshaft actuator bolt hand tight.
16. Verify that all of the colored links and the appropriate timing marks are still aligned. If they are not, repeat the portion of the procedure necessary to align the timing marks.
17. Install the fixed timing chain guide (1) and bolts and tighten to 12 N.m (106 lb in).
18. Install the upper timing chain guide (1) and bolts and tighten to 10 N.m (89 lb in).
19. Reset the timing chain tensioner by performing the following steps: Remove the snap ring. Remove the piston assembly from the body of the timing chain tensioner. Install the EN-45027-2 (2) tensioner into a vise. Install the notch end of the piston assembly into the EN-45027-2 (2) tensioner. Using the EN-45027-1 (1) tensioner, turn the ratchet cylinder into the piston. Reinstall the piston assembly into the body of the tensioner. Install the snap ring.
20. Inspect the timing chain tensioner seal for damage. If damaged, replace the seal.
21. Inspect to ensure all dirt and debris is removed from the timing chain tensioner threaded hole in the cylinder head.
22. Install the timing chain tensioner assembly (1) and tighten to 75 N.m (55 lb ft).
23. The crankshaft balancer must be installed in order to release the tensioner. Refer to «Crankshaft Balancer Installation»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__crankshaft-balancer-installation) .
24. Install EN-48953 locking tool (1) and tighten the bolts into the cylinder head to 10 N.m (89 lb in).
25. Using a torque wrench, tighten the intake camshaft actuator bolt to 30 N.m (22 lb ft), plus 100 degrees using the EN 45059 meter.
26. Using a torque wrench, tighten the exhaust camshaft actuator bolt to 30 N.m (22 lb ft), plus 100 degrees using the EN 45059 meter.
27. Remove EN-48953 locking tool.
28. Install the timing chain oiling nozzle (1) and tighten the bolt to 10 N.m (89 lb in).
29. Apply sealant to the thread of the timing chain guide bolt access hole plug. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
30. Install the timing chain guide bolt access hole plug (1) and tighten to 75 N.m (55 lb ft).

EN-35268-A Camshaft/Front Main Seal Installer

For equivalent regional tools, refer to Special Tools .

1. Install the seal (2) into the front cover using the EN-35268-A installer (1).
2. Ensure that the engine front cover is properly supported when installing the seal.

Engine Front Cover and Oil Pump Installation

1. Install the engine front cover (1) with a new gasket (2).
2. Install the engine front cover bolts and tighten to 25 N.m (18 lb ft).
3. Install the long water pump bolt (1) and tighten to 25 N.m (18 lb ft).
4. Install the drive belt tensioner bracket.
5. Install the drive belt tensioner bracket bolts and tighten to 45 N.m (33 lb ft).
6. Install the drive belt tensioner pivot bolt (2) into the tensioner (1).
7. Position the accessory drive belt tensioner in place. Install the drive belt tensioner bolts (2, 3).
8. Tighten the drive belt tensioner bolt (3) to 22 N.m (16 lb ft).
9. Tighten the drive belt tensioner pivot bolt (2) to 50 N.m (37 lb ft).
10. Tighten the drive belt tensioner pivot bolt a final pass 90 degrees.

Oil Pan Installation

1. Apply a 2.25 mm bead of sealer (1) on the level part of the flange next to the chamfer around the perimeter of the oil pan and the oil suction port opening. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
2. Install the oil pan (1).
3. Install the oil pan bolts and tighten to 25 N.m (18 lb ft) in sequence.

Crankshaft Balancer Installation

Special Tools

1. EN-48585 Crankshaft Balancer Guide
2. EN-48953 Camshaft Actuator Locking Tool
3. EN 38122-A Crankshaft Balancer Holder
4. EN 43653 Flywheel Holding Tool
5. EN 45059 Angle Meter

For equivalent regional tools, refer to Special Tools .

1. Install the EN 38122-A holder into the end of the crankshaft.
2. Install the balancer (1) onto the EN-48585 guide. Use care to properly align the keyway and flats on the balancer with the oil pump drive.
3. Install the EN 38122-A holder (1).
4. Install a new retaining bolt and washer. Use the EN 38122-A holder and a breaker bar to prevent the crankshaft from rotating when tightening the bolt. Tighten the bolt to 150 N.m (111 lb ft) plus 100 degrees using the EN 45059 meter.
5. Install the EN-48953 locking tool (1) and tighten the bolts into the cylinder head. Tighten the EN-48953 locking tool retaining bolts to 10 N.m (89 lb in).
6. Release the timing chain tensioner by applying 45 N.m (33 lb ft) counterclockwise torque to the crankshaft balancer bolt.
7. Remove the EN-48953 locking tool.

Camshaft Cover Installation (LUK)

1. Install NEW camshaft cover grommets and camshaft cover bolts if they are serviced with the grommet.
2. Assemble the camshaft cover (1) and a NEW gasket. Ensure that the gasket is located in the retaining groove in the camshaft cover.
3. Install the cover on the cylinder head and hand start the bolts. Tighten the bolts to 10 N.m (89 lb in).
4. Install the camshaft housing cover insulator (1). Tighten the bolts to 10 N.m (89 lb in).
5. Install the ignition coil (1). Tighten the bolt to 10 N.m (89 lb in).
6. Install the front lift bracket (1).
7. Install the front lift bracket bolts and tighten to 25 N.m (18 lb ft).
8. Install the rear lift bracket (1).
9. Install the rear lift bracket bolts and tighten to 25 N.m (18 lb ft).

Oil Filter with Cap and Seal Installation

Special Tools

EN-44887 Oil Filter Wrench

For equivalent regional tools, refer to Special Tools .

1. Install a new oil filter (2) on the oil filter cap (1).
2. Lubricate the O-ring on the oil filter cap with 5W30 engine oil.
3. Use EN-44887 wrench to install the oil filter cap. Tighten the oil filter cap to 25 N.m (18 lb ft).

Fuel Rail and Injectors Installation

Special Tools

EN-47909 Injector Bore and Sleeve Cleaning Kit

For equivalent regional tools, refer to Special Tools .

1. Clean the fuel injector bore in the cylinder head using the EN-47909 kit.
2. Install the fuel rail (1) with injectors into the cylinder head evenly.
3. Hand tighten the 2 outer fuel rail bolts to seat the injector into the injector bores.
4. Start and hand tighten the remaining fuel rail bolts. Tighten the bolts in sequence to final torque using the following procedure: Tighten first pass in sequence to 25 N.m (18 lb ft). Tighten final pass in sequence to 25 N.m (18 lb ft).
5. Connect the electrical harness to the fuel rail harness connections.
6. Install the fuel injection fuel rail noise shield (1).

Intake Manifold Installation

Special Tools

EN-48896 HP Fuel Pump Installation Alignment Gauge

For equivalent regional tools, refer to Special Tools .

1. Install the intake manifold studs in the manifold face and tighten to 15 N.m (11 lb ft).
2. Install the intake manifold (1). Start and hand tighten the intake manifold bolts and nuts.
3. Tighten the bolts and nuts in sequence to 25 N.m (18 lb ft).
4. Install the intake manifold insulator (2).
5. Install the insulator bolt and tighten to 10 N.m (89 lb in).
6. Install the fuel rail harness connector bracket (1) to the intake manifold. Tighten the bracket bolt to 10 N.m (89 lb in).
7. Use the EN-48896 alignment gauge (2) to ensure that the camshaft lobe is in the base circle position. At base circle position, the tool will be flush with the head (1).
8. Lubricate the high pressure fuel pump cylinder head bore with 5W30 engine oil.
9. Lubricate the high pressure fuel pump roller lifter (1) with 5W30 engine oil and install into the cylinder head bore.
10. Install a NEW fuel pump housing O-ring (2) and gasket (3).
11. Install the fuel pump assembly (4).
12. Start and hand-tighten the fuel pump assembly bolts evenly. Tighten the fuel pump bolts evenly to 15 N.m (11 lb ft).
13. Install and hand-tighten both ends of the NEW high pressure fuel line (1). Tighten the high pressure fuel line fitting nuts to 30 N.m (22 lb ft).
14. Install the fuel pump insulator (2).
15. Install the low pressure fuel pipe assembly (1).
16. Install the fuel pump cover (3) and nut. Tighten the nut to 10 N.m (89 lb in).
17. Install the fuel pump cover bolts. Tighten the bolts to 10 N.m (89 lb in).
18. Install a new throttle body gasket.
19. Install the throttle body (1).
20. Install the throttle body bolts and tighten to 10 N.m (89 lb in).
21. Install the MAP sensor (3). Tighten the sensor bolt to 4 N.m (35 lb in).
22. Install the EVAP canister valve (2) and tighten to 25 N.m (18 lb ft).
23. Install the EVAP canister valve tube (1).
24. Install the O-ring and oil fill tube assembly (3).
25. Install the intake manifold cover (2) onto the camshaft cover ball studs.
26. Install the oil fill cap (1).

Exhaust Manifold Installation (LUK)

1. Install new exhaust manifold studs and tighten to 10 N.m (89 lb in).
2. Install the secondary air injection pipe assembly (1).
3. Install the secondary air injection pipe assembly bolts (2) and tighten to 10 N.m (89 lb in).
4. Install the exhaust manifold gasket (3).
5. Install the exhaust manifold (2) to the cylinder head.
6. Install NEW exhaust manifold to cylinder head retaining nuts (1) finger tight.
7. Tighten the NEW exhaust manifold to cylinder head retaining nuts two passes in sequence: Tighten first pass in sequence to 14 N.m (124 lb in). Tighten final pass in sequence to 14 N.m (124 lb in).
8. Install the block heater (1). Tighten the bolt to 10 N.m (89 lb in).
9. Install the exhaust manifold heat shield (1).
10. Install the exhaust manifold heat shield bolts and tighten to 9 N.m (80 lb in).
11. Coat the threads of the oxygen sensor (1) with antiseize. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
12. Install the oxygen sensor and tighten to 42 N.m (31 lb ft).
13. Install the secondary air injection studs (3 and 4) and tighten to 10 N.m (89 lb in).
14. Install the secondary air injection valve assembly (1) with a NEW gasket (2).
15. Install the secondary air injection bolts (2 and 3) and nuts (1). Tighten the secondary air injection assembly to cylinder head bolts (3) to 22 N.m (16 lb ft). Tighten the secondary air injection assembly to pipe assembly bolts (2) to 10 N.m (89 lb in). Tighten the secondary air injection assembly nuts (1) to 22 N.m (16 lb ft).

Oil Level Indicator and Tube Installation (LUK)

1. Lubricate the oil level indicator tube O-ring. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l__adhesives-fluids-lubricants-and-sealers) .
2. Install the oil level indicator (2) and the oil level indicator tube (1) into the oil pan.
3. Install the oil level indicator tube bracket bolt (3) to the intake manifold and tighten to 10 N.m (89 lb in).
4. Install the electrical wiring harness to the oil level indicator tube.
5. Install the knock sensor wiring clip (4) into the oil level indicator tube.

Engine Flywheel Installation

Special Tools

1. EN-38122-A Crankshaft Balancer Holder
2. EN-43653 Flywheel Holding Tool
3. EN-45059 Angle Meter

For equivalent regional tools, refer to Special Tools .

1. Install the flywheel.
2. Install NEW bolts.
3. Holding the crankshaft balancer with EN-38122-A holder, tighten the bolts evenly. Tighten the bolts to 53 N.m (39 lb ft), plus 25 degrees using the EN-45059 meter

Engine Prelubing

Note. This procedure is not used in Europe.

Special Tools

EN-45299 Engine Preluber

For equivalent regional tools, refer to Special Tools .

1. Remove the oil pressure switch.
2. Install the M12 x 1.75 adapter (1) P/N 509376.
3. Install the flexible hose to the adapter and open the valve.
4. Pump the handle on the EN-45299 preluber (1) in order to flow a minimum of 1-1.9 liters (1-2 quarts) of engine oil. Observe the flow of engine oil through the flexible hose and into the engine assembly.
5. Close the valve and remove the flexible hose and adapter from the engine.
6. Install the oil pressure switch to the engine and tighten to 22 N.m (16 lb ft).
7. Top-off the engine oil to the proper level.

General Description

A crankcase ventilation system is used to consume crankcase vapors in the combustion process instead of venting them to atmosphere. Fresh air from the intake system is supplied to the crankcase, mixed with blow by gases and then passed through a calibrated orifice into the intake manifold.

Scheme 33

The primary control is through the positive crankcase ventilation (PCV) orifice which meters the flow at a rate depending on inlet vacuum. The PCV orifice is an integral part of the camshaft cover. If abnormal operating conditions occur, the system is designed to allow excessive amounts of blow by gases to back flow through the crankcase vent into the intake system to be consumed by normal combustion.

Results of Incorrect Operation

A plugged orifice may cause the following conditions

1. Rough idle
2. Stalling or slow idle speed
3. Oil leaks
4. Sludge in engine

A leaking orifice may cause the following conditions

1. Rough idle
2. Stalling
3. High idle speed

Drive Belt System Description

The drive belt system consists of the following components

1. The drive belt
2. The drive belt tensioner
3. The drive belt idler pulley
4. The crankshaft balancer pulley
5. The accessory drive component mounting brackets
6. The accessory drive components The power steering pump, if belt driven The generator The A/C compressor, if equipped The engine cooling fan, if belt driven The water pump, if belt driven The vacuum pump, if equipped The air compressor, if equipped

The drive belt system may use one belt or two belts. The drive belt is thin so that it can bend backward and has several ribs to match the grooves in the pulleys. There also may be a V-belt style belt used to drive certain accessory drive components. The drive belts are made of different types of rubber (chloroprene or EPDM) and have different layers or plys containing either fiber cloth or cords for reinforcement.

Both sides of the drive belt may be used to drive the different accessory drive components. When the back side of the drive belt is used to drive a pulley, the pulley is smooth.

The drive belt is pulled by the crankshaft balancer pulley across the accessory drive component pulleys. The spring loaded drive belt tensioner keeps constant tension on the drive belt to prevent the drive belt from slipping. The drive belt tensioner arm will move when loads are applied to the drive belt by the accessory drive components and the crankshaft.

The drive belt system may have an idler pulley, which is used to add wrap to the adjacent pulleys. Some systems use an idler pulley in place of an accessory drive component when the vehicle is not equipped with the accessory.

Engine Description

Cylinder Block

The cylinder block is constructed of aluminum alloy by precision sand-casting with 4 cast-in-place iron cylinder liners arranged in-line. The block has 5 crankshaft bearings with the thrust bearing located on the second bearing from the front of the engine. The cylinder block incorporates a bedplate design that forms an upper and lower crankcase. This design promotes cylinder block rigidity and reduced noise and vibration.

Crankshaft

The crankshaft is cast nodular iron with 8 counterweights. The number 8 counterweight is also the ignition system reluctor wheel. The main bearing journals are cross-drilled, and the upper bearings are grooved. The crankshaft has a slip fit balance shaft drove sprocket. Number 2 main bearing is the thrust bearing. The crankshaft balancer is used to control torsional vibration.

Connecting Rod and Piston

The connecting rods are powdered metal. The connecting rod incorporates the floating piston pin. The pistons are cast aluminum. The piston rings are of a low tension type to reduce friction. The top compression ring is ductile iron with a molybdenum facing and phosphate coated sides. The second compression ring is gray iron. The oil ring is a 3-piece spring construction with chromium plating.

Oil Pan

The oil pan is die cast aluminum. The oil pan includes an attachment to the transmission to provide additional structural support.

Balance Shaft Assembly

There are 2 block mounted balance shafts located on each side of the crankcase at the bottom of the cylinder bores. The balance shafts are driven by a single roller chain that also drives the water pump. The chain is tensioned by a hydraulic tensioner that is supplied pressure by the engine oil pump. This design promotes the maximum effectiveness of the balance shaft system and reduces noise and vibration.

Cylinder Head

The cylinder head is a semi-permanent mold. Pressed-in powdered metal valve guides and valve seat insets are used. The fuel injection nozzle is located in the intake port. The cylinder head incorporates camshaft journals and camshaft caps.

Valves

There are 2 intake and 2 exhaust valves per cylinder. Rotators are used on all of the intake valves. The rotators are located at the bottom of the valve spring to reduce valve train reciprocating mass. Positive valve stem seals are used on all valves.

Camshaft

Two camshafts are used, one for all intake valves, the other for all exhaust valves. The camshafts are cast iron.

Valve Lash Adjusters

The valve train uses a roller finger follower acted on by a hydraulic lash adjuster. The roller finger follower reduces friction and noise.

Camshaft Cover

The camshaft cover has a steel crankcase ventilation baffling incorporated. The camshaft cover has mounting locations for the ignition system.

Camshaft Drive

A roller chain is used for camshaft drive. There is a tensioner and active guide used on the slack side of the chain to control chain motion and noise. The chain drive promotes long valve train life and low maintenance.

Intake and Exhaust Manifold

The intake manifold is made of composite plastic. The exhaust manifold is cast iron. The intake manifold incorporates a distribution and control system for positive crankcase ventilation (PCV) gases. The exhaust manifold is a dual plane design that promotes good low end torque and performance.

Scheme 34

Oil is applied under pressure to the crankshaft (1), connecting rods, balance shaft assembly, camshaft bearing surfaces, valve lash adjusters and timing chain hydraulic tensioner. All other moving parts are lubricated by gravity flow or splash. Oil enters the gerotor type oil pump through a fixed inlet screen. The oil pump is driven by the crankshaft. The oil pump body is within the engine front cover. The pressurized oil from the pump passes through the oil filter. The oil filter is located on the left rear side of the engine block. The oil filter is housed in a casting that is integrated with the engine block. The oil filter is a disposable cartridge type. A by-pass valve in the filter cap allows continuous oil flow in case the oil filter should become restricted. Oil then enters the gallery where it is distributed to the balance shafts, crankshaft, camshafts and camshaft timing chain oiler nozzle. The connecting rod bearings are oiled by constant oil flow passages through the crankshaft connecting the main journals to the rod journals. A groove around each upper main bearing furnishes oil to the drilled crankshaft passages. The pressurized oil passes through the cylinder head restrictor orifice into the cylinder head and then into each camshaft feed gallery. Cast passages feed each hydraulic element adjuster and drilled passages feed each camshaft bearing surface. An engine oil pressure switch or sensor is installed at the end. Oil returns to the oil pan through passages cast into the cylinder head. The timing chain lubrication drains directly into the oil pan.

Cleanliness and Care

An automobile engine is a combination of many machined, honed, polished, and lapped surfaces with tolerances that are measured in ten thousandths of an inch. When any internal engine parts are serviced, care and cleanliness are important. A liberal coating of engine oil should be applied to friction areas during assembly to protect and lubricate the surfaces during initial operation. Throughout this section, it should be understood that proper cleaning and protection of machined surfaces and friction areas are part of the repair procedure. This is considered standard shop practice even if not specifically stated.

When valve train components are removed for service, they should be retained in order. At the time of installation, they should be installed in the same locations and with the same mating surfaces as when removed.

Separating Parts

Note. Disassembly of the piston, press fit design piston pin, and connecting rod may create scoring or damage to the piston pin and piston pin bore. If the piston, pin, and connecting rod have been disassembled, replace the components as an assembly. Many internal engine components will develop specific wear patterns on their friction surfaces. When disassembling the engine, internal components MUST be separated, marked, or organized in a way to ensure installation to their original location and position.

Separate, mark, or organize the following components

1. Piston and the piston pin
2. Piston to the specific cylinder bore
3. Piston rings to the piston
4. Connecting rod to the crankshaft journal
5. Connecting rod to the bearing cap A paint stick or etching/engraving type tool are recommended. Stamping the connecting rod or cap near the bearing bore may affect component geometry.
6. Crankshaft main and connecting rod bearings
7. Camshaft and valve lash adjusters
8. Valve lash adjusters, lash adjuster guides, pushrods and rocker arm assemblies
9. Valve to the valve guide
10. Valve spring and shim to the cylinder head location
11. Engine block main bearing cap location and direction
12. Oil pump drive and driven gears

EN-28410 Gasket Remover

For equivalent regional tools, refer to Special Tools .

Gasket Reuse and Applying Sealants

1. Do not reuse any gasket unless specified.
2. Gaskets that can be reused will be identified in the service procedure.
3. Do not apply sealant to any gasket or sealing surface unless called out in the service information.

Separating Components

1. Use a rubber mallet to separate components.
2. Bump the part sideways to loosen the components.
3. Bumping should be done at bends or reinforced areas to prevent distortion of parts.

Cleaning Gasket Surfaces

1. Remove all gasket and sealing material from the part using the EN-28410 remover or equivalent.
2. Care must be used to avoid gouging or scraping the sealing surfaces.
3. Do not use any other method or technique to remove sealant or gasket material from a part.
4. Do not use abrasive pads, sand paper, or power tools to clean the gasket surfaces. These methods of cleaning can cause damage to the component sealing surfaces. Abrasive pads also produce a fine grit that the oil filter cannot remove from the oil. This grit is abrasive and has been known to cause internal engine damage.

Assembling Components

1. When assembling components, use only the sealant specified or equivalent in the service procedure.
2. Sealing surfaces should be clean and free of debris or oil.
3. Specific components such as crankshaft oil seals or valve stem oil seals may require lubrication during assembly.
4. Components requiring lubrication will be identified in the service procedure.
5. When applying sealant to a component, apply the amount specified in the service procedure.
6. Do not allow the sealant to enter into any blind threaded holes, as it may prevent the bolt from clamping properly or cause component damage when tightened.
7. Tighten bolts to specifications. Do not overtighten.

Use of Room Temperature Vulcanizing (RTV) and Anaerobic Sealant

Three types of sealer are commonly used in engines. These are RTV sealer, anaerobic gasket eliminator sealer, and pipe joint compound. The correct sealer and amount must be used in the proper location to prevent oil leaks. DO NOT interchange the 3 types of sealers. Use only the specific sealer or the equivalent as recommended in the service procedure.

Room Temperature Vulcanizing (RTV) Sealer

1. RTV sealant hardens when exposed to air. This type sealer is used where 2 rigid parts, such as the lower crankcase and the engine block, are assembled together.
2. Do not use RTV sealant in areas where extreme temperatures are expected. These areas include: exhaust manifold, head gasket, or other surfaces where a gasket eliminator is specified.
3. Follow all safety recommendations and directions that are on the container. To remove the sealant or the gasket material, refer to «Replacing Engine Gaskets»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
4. Apply RTV to a clean surface. Use a bead size as specified in the procedure. Run the bead to the inside of any bolt holes. Do not allow the sealer to enter any blind threaded holes, as it may prevent the bolt from clamping properly or cause damage when the bolt is tightened.
5. Assemble components while RTV is still wet, within 3 minutes. Do not wait for RTV to skin over.
6. Tighten bolts to specifications. Do not overtighten.

Anaerobic Sealer

1. Anaerobic gasket eliminator hardens in the absence of air. This type sealer is used where two rigid parts (such as castings) are assembled together. When two rigid parts are disassembled and no sealer or gasket is readily noticeable, the parts were probably assembled using a gasket eliminator.
2. Follow all safety recommendations and directions that are on the container. To remove the sealant or the gasket material, refer to «Replacing Engine Gaskets»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
3. Apply a continuous bead of gasket eliminator to one flange. Surfaces to be resealed must be clean and dry.
4. Spread the sealer evenly with your finger to get a uniform coating on the sealing surface.
5. Do not allow the sealer to enter any blind threaded holes, as it may prevent the bolt from clamping properly or cause damage when tightened.
6. Tighten bolts to specifications. Do not overtighten.
7. After properly tightening the fasteners, remove the excess sealer from the outside of the joint.

Pipe Joint Compound

1. Pipe joint compound is a pliable sealer that does not completely harden.
2. Do not use pipe joint compound in areas where extreme temperatures are expected. These areas include: exhaust manifold, head gasket, or other surfaces where gasket eliminator is specified.
3. Follow all safety recommendations and directions that are on the container. To remove the sealant or the gasket material, refer to «Replacing Engine Gaskets»(/buick/lacrosse/ii-2009-2013/remont/mechanical/#engine-mechanical-24l) .
4. Apply the pipe joint compound to a clean surface. Use a bead size or quantity as specified in the procedure. Run the bead to the inside of any bolt holes. Do not allow the sealer to enter any blind threaded holes, as it may prevent the bolt from clamping properly or cause component damage when the bolt is tightened.
5. Apply a continuous bead of pipe joint compound to one sealing surface. Sealing surfaces to be resealed must be clean and dry.
6. Tighten the bolts to specifications. Do not overtighten.

Tools and Equipment

Special tools are listed and illustrated throughout this section with a complete listing at the end of the section. These tools, or their equivalents, are specially designed to quickly and safely accomplish the operations for which they are intended. The use of these special tools will also minimize possible damage to engine components. Some precision measuring tools are required for inspection of certain critical components. Torque wrenches and a torque angle meter are necessary for the proper tightening of various fasteners.

To properly service the engine assembly, the following items should be readily available

1. Approved eye protection and safety gloves
2. A clean, well lit, work area
3. A suitable parts cleaning tank
4. A compressed air supply
5. Trays or storage containers to keep parts and fasteners organized
6. An adequate set of hand tools
7. Approved engine repair stand
8. An approved engine lifting device that will adequately support the weight of the components

Illustration Tool Number/Description BO-38185 J-38185 Hose Clamp Pliers South America Use Local Equivalent CH-48027 Digital Pressure Gauge South America Use Local Equivalent EN-8037 J-8037 Ring Compressor South America Use Local Equivalent EN-8062 J 8062 KM-348 09916-14510 7-0006798 Valve Spring Compressor- Head Off EN-8087 J 8087 Cylinder Bore Gauge South America Use Local Equivalent EN-21867-850 J-21867-850 KM-498-B KM-6106 7-0006833 Oil Pressure Gauge Adapter EN 22738-B GE 22738-B J 22738-B J 9666 Valve Spring Tester South America Use Local Equivalent EN 23951 J 23951 Valve Manometer South America Use Local Equivalent EN 28410 J 28410 Gasket Remover South America Use Local Equivalent EN 28467-B J 28467-B X-0206951 L-0906004 Universal Engine Support Fixture EN 28467-500B J 28467-500B Engine Support Fixture EN 35268-A J 35268-A Camshaft/Front Main Seal Installer EN 35667-A J 35667-A Cylinder Head Leakdown Tester South America Use Local Equivalent EN-36017 J 36017 KM-840- Removal KM-6152- Installation V-0506032 Valve Seal Remover EN-38122-A J 38122-A KM-J-38122-A KM-956-1 Crankshaft Balancer Holder EN-38188 J 38188 Cylinder Head Broken Bolt Extractor Kit South America Use Local Equivalent EN-42067 J 42067 KM-J-42067 Rear Main Seal Installer EN-42385-850 J 42385-850 Thread Repair Kit South America Use Local Equivalent EN 43405 J 43405 Engine Support Fixture Adapter EN-43649 J 43649 Valve Spring Compressor South America Use Local Equivalent EN-43650 J 43650 Balance Shaft Bearing Remover and Installer EN 43653 J 43653 KM-652 Flywheel Holding Tool South America Use Local Equivalent EN-43963 J 43963 KM-6149 V-0306983 Valve Spring Compressor (off car) EN-43966 J 43966 V-0506030 Connecting Rod Guides EN-44887 J 44887 KM-6150 Oil Filter Wrench EN 45025 J 45025 Belt Tensioner Wrench EN-45027 J 45027 Tensioner Tool South America Use Local Equivalent EN-45059 J 45059 KM-470-B Angle Meter South America Use Local Equivalent EN-45299 J 45299 Engine Pre-Luber South America Use Local Equivalent EN 46745 J 43654 Piston Pin Clip Remover/Installer South America Use Local Equivalent EN 47836 Piston Ring Compressor South America Use Local Equivalent EN-47909 Injector Bore and Sleeve Cleaning Kit EN 48366 EN 48368 EN 48953 Camshaft Actuator Locking Tool South America Use Local Equivalent EN 48585 Crankshaft Balancer Guide South America Use Local Equivalent EN 48749 J 44217 Timing Chain Retention Tool Kit South America Use Local Equivalent EN 48896 HP Fuel Pump Installation Alignment Gauge EN 49245 EN-48266 and EN-49245-1 Fuel Injector Seal Installer/Sizer EN 49247 Injector Retaining Clip Installer EN 49248 Fuel Rail Assembly Remover GE-7872 J 7872 Magnetic Base Dial Indicator Set South America Use Local Equivalent GE-42220 J 28428-E J 42220 Universal 12V Leak Detection Lamp South America Use Local Equivalent J-39580 J-9703386 J-9703392 L-0806003 L-0906001 L-0906002 L-0906003 L-0906004 Engine Support Table

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See also:
• Diagnostic System Check - Vehicle
• Symptoms - Engine Controls
• Spark Plug Replacement
• Belt Dressing Caution
• Fastener Caution
• Vibration Analysis - Engine
• Water Pump Replacement (L4)
• Drive Belt Tensioner Pivot Bolt Caution
• Starter Replacement (LUK)
• Lifting and Jacking the Vehicle
• Radiator Inlet Hose Replacement (LUK)
• Starter Generator Replacement
• Front Compartment Splash Shield Replacement
• Power Brake Booster Vacuum Rear Pipe Replacement (2.4L)
• Cooling System Draining and Filling (Static Fill)
• Cooling System Draining and Filling (GE 47716)
• Exhaust Manifold Replacement (LUK)
• Transmission Replacement
• Fuel Pressure Relief
• Metal Collar Quick Connect Fitting Service
• Tire and Wheel Removal and Installation
• Steering Linkage Outer Tie Rod Replacement
• Stabilizer Shaft Link Replacement
• Front Wheel Drive Shaft Replacement (GNB)
• Front Wheel Drive Shaft Replacement (GNA)
• Intermediate Steering Shaft Replacement
• Crankshaft Position System Variation Learn
• Special Tools
• Safety Glasses Warning
• Component Fastener Tightening Caution
• Safety Glasses and Compressed Air Warning
• Cleaning Solvent Warning
• Disassembled Views
• Base Engine Misfire without Internal Engine Noises
• Base Engine Misfire with Abnormal Internal Lower Engine Noises
• Base Engine Misfire with Abnormal Valve Train Noise
• Base Engine Misfire with Coolant Consumption
• Base Engine Misfire with Excessive Oil Consumption
• Engine Noise on Start-Up, but Only Lasting a Few Seconds
• Upper Engine Noise, Regardless of Engine Speed
• Lower Engine Noise, Regardless of Engine Speed
• Engine Noise Under Load
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Engine Compression Test
• Oil Consumption Diagnosis
• Oil Pressure Diagnosis and Testing
• Oil Leak Diagnosis
• Drive Belt Tensioner Diagnosis
• Camshaft Position Intake Actuator Replacement
• Camshaft Position Exhaust Actuator Replacement
• Cylinder Head Cleaning and Inspection (LAF, LEA, or LUK)
• Cylinder Head Replacement
• Engine Mechanical Specifications (LUK)
• Oil Pump Disassemble
• Engine Front Cover and Oil Pump Installation
• Crankshaft and Bearing Cleaning and Inspection
• Engine Block Assemble
• Fastener Tightening Specifications (LAF, LEA, or LUK)
• Drive Belt Replacement
• Drive Belt Tensioner Replacement
• Engine Support Fixture
• Adhesives, Fluids, Lubricants, and Sealers
• Timing Chain Tensioner Replacement
• Engine Oil and Oil Filter Replacement
• Thread Repair
• Engine Block Cleaning and Inspection
• Piston, Connecting Rod, and Bearing Installation (LAF, LAT, LE5, LE9, LEA, or LUK)
• Separating Parts
• Crankshaft Balancer Installation