Engine Mechanical - 3.4l v6 - VIN (E) (On-Vehicle) Chevrolet Impala VIII

Fastener Tightening Specifications

TORQUE SPECIFICATIONS

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Engine Mechanical Specifications

Engine Mechanical Specifications

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Diagnostic Starting Point - Engine Mechanical

Begin the system diagnosis by reviewing the description and operation information. This will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the description and operation information will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Engine Mechanical in order to identify the correct procedure for diagnosing the system and where the procedure is located.

Strategy Based Diagnostics

1. Perform «DIAGNOSTIC SYSTEM CHECK -- ENGINE CONTROLS»(/chevrolet/impala/viii-1999-2006/remont/testing-diagnostics/#engine-controls-self-diagnostics-34l__diagnostic-system-check-engine-controls) before using the symptom tables if applicable.
2. Review the system operations in order to familiarize yourself with the system functions.

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 problem. 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. Refer to «CHECKING AFTERMARKET ACCESSORIES»(/chevrolet/impala/viii-1999-2006/remont/accessories-control-systems/#wiring-systems-general-information__checking-aftermarket-accessories) .
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. See «Base Engine Misfire Without Internal Engine Noises»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
2. See «Base Engine Misfire With Abnormal Internal Lower Engine Noises»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. See «Base Engine Misfire With Abnormal Valve Train Noise»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. See «Base Engine Misfire With Coolant Consumption»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
5. See «Base Engine Misfire With Excessive Oil Consumption»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
6. See «Engine Compression Test»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-compression-test) .
7. See «Engine Noise On Start-Up, But Only Lasting A Few Seconds»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
8. See «Upper Engine Noise, Regardless Of Engine Speed»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
9. See «Lower Engine Noise, Regardless Of Engine Speed»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
10. See «Engine Noise Under Load»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
11. See «Engine Will Not Crank - Crankshaft Will Not Rotate»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
12. See «Oil Consumption Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__oil-consumption-diagnosis) .
13. See «Oil Pressure Diagnosis & Testing»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
14. See «Oil Leak Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__oil-leak-diagnosis) .
15. See «Drive Belt Chirping Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
16. See «Drive Belt Squeal Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
17. See «Drive Belt Whine Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
18. See «Drive Belt Rumbling Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
19. See «Drive Belt Vibration Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
20. See «Drive Belt Falls Off Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
21. See «Drive Belt Excessive Wear Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
22. See «Drive Belt Tensioner Diagnosis»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .

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Engine Compression Test

A compression pressure test of the engine cylinders determines the condition of the rings, the valves, and the head gasket.

Important: Remove the Powertrain Control Module (PCM) and the ignition fuses from the I/P fuse block.

1. Disable the ignition.
2. Disable the fuel systems.
3. Remove the spark plugs from all the cylinders.
4. Remove the air duct from the throttle body.
5. Block the throttle plate in the open position.
6. Measure the engine compression, using the following procedure: 6.1. Firmly install the compression gauge to the spark plug hole. 6.2. Have an assistant crank the engine through at least 4 compression strokes in the testing cylinder. 6.3. Record the readings on the gauge at each stroke. 6.4. Disconnect the gauge. 6.5. Repeat the compression test for each cylinder.
7. Record the compression readings from all of the cylinders. The lowest reading should not be less than 70 percent of the highest reading. No cylinder reading should be less than 689 kPa (100 psi).
8. The following list contains examples of the possible measurements: When the compression measurement is normal, the compression builds up quickly and evenly to the specified compression on each cylinder. When the compression is low on the first stroke and tends to build up on the following strokes, but does not reach the normal compression, the piston rings may be the cause. If the compression improves considerably with the addition of three squirts of oil, the piston rings may be the cause. When the compression is low on the first stroke and does not build up in the following strokes, the valves may be the cause. The addition of oil does not affect the compression, the valves may be the cause. When the compression is low on two adjacent cylinders, or coolant is present in the crankcase, the head gasket may be the cause.
9. Remove the block from the throttle plate.
10. Install the air duct to the throttle body.
11. Install the spark plugs.
12. Install the Powertrain Control Module (PCM) fuse.
13. Install the ignition fuse to the I/P fuse block.

Testing Procedure

Tools Required

J 35667-A Cylinder Head Leakdown Tester

With the use of air pressure, a cylinder leakage test will aid in the diagnosis. Use the cylinder leakage test in conjunction with the engine compression test in order to isolate the cause of leaking cylinders.

1. Disconnect the negative battery cable.
2. Remove the spark plugs.
3. Install the J 35667-A .
4. Measure each cylinder on the compression stroke, with both valves closed. Important: Hold the crankshaft balancer bolt in order to prevent piston movement.
5. Apply air pressure, using the J 35667-A . Refer to the manufacturer's instructions.
6. Record the cylinder leakage readings for each cylinder. Important: Normal cylinder leakage is from 12 to 18 percent. Make a note of any cylinder with more leakage than the other cylinders. Any cylinder with 30 percent leakage or more requires service.
7. Inspect the 4 primary areas in order to properly diagnose a leaking cylinder.
8. If air is heard from the intake or exhaust system, perform the following procedure: Remove the valve rocker arm cover of the suspect cylinder head. Ensure that both valves are closed. Inspect the cylinder head for a broken valve spring. Remove and inspect the suspect cylinder head.
9. If air is heard from the crankcase system at the crankcase oil filler tube, perform the following procedure: 9.1. Remove the piston from the suspect cylinder. 9.2. Inspect the piston and connecting rod assembly. Refer to «PISTON, CONNECTING ROD & BEARINGS -- CLEANING»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-unit-repair__piston-connecting-rod-bearings) . 9.3. Inspect the engine block. Refer to «ENGINE BLOCK -- CLEANING & INSPECTION»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-unit-repair__engine-block-cleaning-inspection) .
10. If bubbles are found in the radiator, perform the following procedure: Remove and inspect both cylinder heads. Refer to «CYLINDER HEAD -- CLEANING & INSPECTION»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-unit-repair__cylinder-head-cleaning-inspection) . Inspect the engine block. Refer to «ENGINE BLOCK -- CLEANING & INSPECTION»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-unit-repair__engine-block-cleaning-inspection) .
11. Remove the J 35667-A .
12. Install the spark plugs.
13. Connect the negative battery cable.

Oil Consumption Diagnosis

An engine that has excessive oil consumption uses 0.9 L (1 qt) of oil, or more, within 3 200 km (2,000 mi). The following list indicates the conditions and corrections of excessive oil consumption

1. An improperly read oil level indicator dipstick Inspect the oil level while the vehicle is parked on a level surface. Allow adequate drain-down time.
2. Improper oil viscosity Use the recommended SAE viscosity for prevailing temperatures.
3. Continuous high-speed driving
4. Severe hauling, such as a trailer. This causes decreased oil mileage.
5. A malfunctioning crankcase ventilation system
6. External oil leaks Tighten the bolts, as needed. Replace the gaskets and seals, as needed.
7. Worn or omitted valve guides and/or valve stem seals Ream the guides. Install oversized service valves and/or new valve stem seals.
8. Broken or worn piston rings
9. Improperly installed or unseated piston rings
10. Improperly installed or improperly fitted piston
11. Plugged cylinder head gasket oil drain holes
12. Damaged intake gaskets

Low Or No Oil Pressure

The following conditions may cause low or no oil pressure

1. Low oil level. Fill to the full mark on the oil level indicator.
2. Incorrect or malfunctioning oil pressure switch. Replace the oil pressure switch.
3. Incorrect or malfunctioning oil pressure gage. Replace the oil pressure gage.
4. Improper oil viscosity or diluted oil Install oil of proper viscosity for expected temperature. Install new oil if the oil is diluted.
5. A worn or dirty oil pump. Clean or replace the oil pump.
6. A plugged oil filter. Replace the oil filter.
7. A loose or plugged oil pickup screen. Replace the oil pickup screen.
8. A hole in the oil pickup tube. Replace the oil pickup tube.
9. Excessive bearing clearance. Replace the bearings.
10. Cracked, porous, or plugged oil gallery. Repair or replace the engine block.
11. Missing or improperly installed gallery plugs. Install or repair the plugs as needed.
12. A stuck pressure regulator valve Inspect the pressure regulator valve for sticking in the bore. Inspect the bore for scoring and burrs.
13. A worn or poorly machined camshaft. Replace the camshaft.
14. Worn valve guides. Repair the valve guides as needed.

Oil Pressure Testing

Tools Required

J 25087-C Oil Pressure Tester

If the vehicle has low oil pressure complete the following steps

1. Inspect the oil level.
2. Raise and support the vehicle. Refer to «Oil Pressure Diagnosis & Testing»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Remove the oil filter.
4. Assemble the plunger valve in the large hole of the J 25087-C base. Insert the hose in the small hole of the J 25087-C base. Connect the gage to the end of the hose.
5. Insert the flat side of the rubber plug in the bypass valve without depressing the bypass valve.
6. Install the J 25087-C on the filter mounting pad.
7. Start the engine.
8. Inspect the overall oil pressure, the oil pressure switch, and for noisy lifters. Ensure that the engine is at operating temperature before inspecting the oil pressure. The oil pressure should be approximately 414 kPa (60 psi) at 1,850 RPM using 5W-30 engine oil.
9. If adequate oil pressure is indicated, test the oil pressure switch.
10. If a low reading is indicated, press the valve on the tester base in order to isolate the oil pump and/or its components from the lubricating system. An adequate reading at this time indicates a good pump and the previous low pressure was due to worn bearings, etc. A low reading while pressing the valve indicates a faulty pump.

Oil Leak Diagnosis

Tools Required

J 28428-E High Intensity Black Light Kit

You may repair most fluid leaks by first visually locating the leak, repairing or replacing the component, or by resealing the gasket surface. Once the leak is identified, determine the cause of the leak. Repair the leak and the cause of leak.

Locating and Identifying the Leak

Use the visual inspection method in order to determine if the leaking fluid is one of the following items

1. Engine oil
2. Transmission fluid
3. Power steering fluid
4. Brake fluid
5. Some other fluid

Visual Inspection Method

Complete the following steps in order to perform the visual inspection method

1. Bring the vehicle to normal operating temperature.
2. Park the vehicle over a large sheet of paper, or other clean surface.
3. Wait several minutes, then inspect for dripping fluids.
4. Identify the type of fluid, and the approximate location of the leak.
5. Visually inspect the suspected area. Use a small mirror if necessary.
6. Inspect for leaks at sealing surfaces, fittings, or from cracked or damaged components.
7. If you cannot locate the leak, perform the following steps: 7.1. Completely clean the entire engine and surrounding components. 7.2. Operate the vehicle for several miles at normal operation temperature and at varying speeds. 7.3. Park the vehicle over a large sheet of paper, or other clean surface. 7.4. Wait several minutes, then inspect for dripping fluids. 7.5. Identify the type of fluid, and the approximate location of the leak. 7.6. Visually inspect the suspected area. Use a small mirror if necessary.
8. If you still cannot locate the leak, use the powder method or the black light and dye method.

Powder Method

1. Completely clean the entire engine and surrounding components.
2. Apply an aerosol-type powder, baby powder, foot powder, etc., to the suspected area.
3. Operate the vehicle for several miles at normal operation temperature and at varying speeds.
4. Identify the type of fluid, and the approximate location of the leak, from the discolorations in the powder surface.
5. Visually inspect the suspected area. Use a small mirror to assist in looking at hard to see areas. See «Possible Causes For Leaks»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__possible-causes-for-leaks) .

Black Light and Dye Method

A dye and light kit is available for finding leaks.

1. Use the J 28428-E or the equivalent. Refer to the manufacturer's instructions when using the tool.
2. Visually inspect the suspected area. Use a small mirror if necessary. See «Possible Causes For Leaks»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__possible-causes-for-leaks) .

Possible Causes For Leaks

Inspect the vehicle for the following conditions

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1. Higher than recommended fluid levels
2. Higher than recommended fluid pressures
3. Plugged or malfunctioning fluid filters or pressure bypass valves
4. Plugged or malfunctioning engine ventilation system
5. Improperly tightened or damaged fasteners
6. Cracked or porous components
7. Improper sealants or gaskets where required
8. Improper sealant or gasket installation
9. Damaged or worn gaskets or seals
10. Damaged or worn sealing surfaces

Diagnostic Aids

The symptom may be intermittent due to moisture on the drive belt or the pulleys. It may be necessary to spray a small amount of water on the drive belt 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.

A loose or improper installation of a body component, a suspension component, or other items of the vehicle may cause the chirping 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 belt 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 belt 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 misalign pulley using a straight edge in the pulley grooves across two or three pulleys. If a misalign 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) - Replacing the drive belt when it is not damaged or there is not excessive pilling will only be a temporary repair.

A loose or improper installation of a body component, a suspension component, or other items of the vehicle may cause the squeal noise.

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.

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 belt and operating the engine for a brief period will verify the squeal noise is the drive belt or an accessory drive component. 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 belt removed.
3. 4) - This test is to verify that an accessory drive component does not have a seized bearing. With the belt remove test the bearings in the accessory drive components for turning smoothly. Also test the accessory drive components with the engine operating by varying the load on the components to verify that the components operate properly.
4. 5) - 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.
5. 6) - 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.
6. 7) - 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 misalign pulley using a straight edge in the pulley grooves across two or three pulleys. If a misalign pulley is found refer to that accessory drive component for the proper installation procedure for that pulley.
7. 8) - This test is to verify that the pulleys are the correct diameter or width. Using a known good vehicle compare the pulley sizes.

The drive belt will not cause the whine noise.

If the whine noise is intermittent, verify the accessory drive components by varying their loads making sure they are operated to their maximum capacity. Such items but not limited to may be an A/C system overcharged, the power steering system restricted or the wrong fluid, or the generator failing.

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

1. 3) - This test is to verify that the noise is being caused by the accessory drive components. 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 belt removed.
2. 4) - The inspection should include checking the drive belt tensioner and the drive belt idler pulley bearings. The drive belt may have to be installed and the accessory drive components operated separately by varying their loads. Refer to the suspected accessory drive component for the proper inspection and replacement procedure.

Vibration from the engine operating may cause a body component or another part of the vehicle to make rumbling noise.

The drive belt may have a 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 belt is 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 the drive belt is causing the rumbling noise. Rumbling noise may be confused with an internal engine noise due to the similarity in the description. 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 belt removed.
3. 4) - Inspecting the drive belt is to ensure that it is 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.

The accessory drive components can have an affect on engine vibration. Such as 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 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 such as the exhaust system, or the drivetrain.
2. 3) - This test is to verify that the drive belt or accessory drive components may be causing the vibration. 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 belt removed.
3. 4) - The drive belt may cause a vibration. While the drive belt is removed this is the best time to inspect the condition of the belt.
4. 6) - Inspecting of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed.
5. 8) - Inspect the water pump shaft for being bent. Also inspect the water pump bearings for smoothness and excessive play. Compare the water pump with a known good water pump.
6. 9) - Accessory drive component brackets that are bent, cracked, or loose may put extra strain on that accessory component causing it to vibrate.

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.

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 misalign pulley using a straight edge in the pulley grooves across two or three pulleys. If a misalign 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.

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) - 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.
2. 3) - The installation of a drive belt that is two wide or two narrow will cause wear on the drive belt. The drive belt ribs should match all of the grooves on all of the pulleys.
3. 4) - 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.

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Removal Procedure

Important: After the new drive belt is installed, make sure that the mark on the drive belt tensioner is in range, as indicated on the tensioner housing.

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1. Using a 3/8 drive breaker bar (1) rotate the drive belt tensioner in order to release the pressure on the drive belt.
2. Remove the drive belt.

Scheme 19

1. Install the drive belt to all of the pulleys except the generator pulley.
2. Rotate the drive belt tensioner in order to install the drive belt over the generator pulley.
3. Make sure that the drive belt is properly routed. Important: Make sure the mark on the drive belt tensioner is in range, as indicated on the tensioner housing.
4. Make sure the drive belt tensioner is operating properly.

Scheme 20

1. Reposition the coolant recovery reservoir for access.
2. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Remove the drive belt tensioner bolt.
4. Remove the drive belt tensioner.

Installation Procedure

1. Install the drive belt tensioner.
2. Install the drive belt tensioner bolt. Tighten the drive belt tensioner bolt to 50 N.m (37 ft lbs).
3. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Install the coolant recovery reservoir.

Engine Mount Inspection

Important: Before replacing any engine mount due to suspected fluid loss, verify that the source of the fluid is the engine mount, not the engine or accessories.

1. Install the engine support fixture. Refer to «Engine Support Fixture»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-support-fixture) . Raise the engine in order to remove the weight from the engine mount and create slight tension in the rubber.
2. Observe the engine mount while raising the engine. Replace the engine mount if the engine mount exhibits any of the following conditions: The hard rubber surface 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.
3. If there is movement between the metal plate of the engine mount and its attaching points, lower the engine on the engine mount. Tighten the nuts attaching the engine mount to the frame or engine mount bracket. Refer to «Engine Mount Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .

Engine Support Fixture

Tools Required

1. J 28467-B Universal Engine Support Fixture
2. J 36462-A Engine Support Adapter Leg Set
3. J-28467-501 Engine Support Fixture Legs

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Scheme 24

1. Disconnect the negative battery cable.
2. Remove the left engine mount strut and the bracket from the upper radiator support. Refer to «Engine Mount Strut Bracket Replacement - Upper Radiator Support»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Assemble the J-28467-501 (2) to the J 28467-B cross bar (1).
4. Install the J 28467-B (1) and the J-28467-501 (2) to the fender rails.
5. Install the J 36462-A (1) to the cross bar (2).
6. Install the support lift hook (1) to the cross bar (2).
7. Install the support hook (1) to the right engine lift hook (3).
8. Install the support hook (1) to the J 36462-A (2).
9. Install the support hook (1) to the left engine lift hook (3).
10. Raise the engine to release the pressure off of the engine mounts.

Scheme 25

Scheme 26

1. Disconnect the battery ground cable.
2. Remove the throttle body air inlet duct.
3. Remove the engine mount struts. Refer to «Engine Mount Strut (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) and «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Raise and suitably support the vehicle.
5. Remove the three-way catalytic converter pipe from the right rear exhaust manifold.
6. Remove the right front wheel and tire.
7. Remove the right engine splash shield.
8. Remove the engine mount lower nuts.
9. Raise the engine, using the universal engine support fixture. Refer to «Engine Support Fixture»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-support-fixture) .
10. Remove the bolts which secure the engine mount bracket to the oil pan.
11. Remove the engine mount and the engine mount bracket.
12. Remove the engine mount upper nuts.
13. Remove the engine mount from the engine mount bracket.

Scheme 27

1. Install the engine mount to the engine mount bracket.
2. Install the engine mount upper nuts. Tighten the upper nuts to 47 N.m (35 ft lbs).
3. Install the engine mount bracket with the engine mount to the oil pan.
4. Install the bolts which secure the engine mount bracket to the oil pan. Tighten the bolts to 58 N.m (43 ft lbs).
5. Lower the vehicle.
6. Lower the engine.
7. Raise and suitably support the vehicle.
8. Install the engine mount lower nuts. Tighten the lower nuts to 43 N.m (32 ft lbs).
9. Install the right engine splash shield.
10. Install the right front wheel and tire.
11. Connect the three-way catalytic converter pipe to the right rear exhaust manifold.
12. Lower the vehicle.
13. Remove the engine support fixture.
14. Install the engine mount struts.
15. Install the throttle body air inlet duct.
16. Connect the battery ground cable.

Engine Mount Bracket - Replacement

Tools Required

1. J 28467-90A Engine Support Adapters
2. J 28467-B Universal Engine Support Fixture
3. J 36462-A Engine Support Adapter Leg Set

Scheme 28

Scheme 29

1. Disconnect the battery ground cable.
2. Remove the throttle body air inlet duct.
3. Remove the engine mount struts. Refer to «Engine Mount Strut (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) and «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Raise and suitably support the vehicle.
5. Remove the three-way catalytic converter pipe from the right exhaust manifold.
6. Remove the right front wheel and tire.
7. Remove the right engine splash shield.
8. Remove the bolts which secure the engine mount bracket to the oil pan.
9. Install J 28467-90A, J 36462-A , and J 28467-B . Refer to «Engine Support Fixture»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-support-fixture) .
10. Raise the engine.
11. Remove the engine mount upper nuts.
12. Remove the engine mount bracket from the engine mount.

1. Install the engine mount bracket to the engine mount.
2. Install the engine mount upper nuts. Tighten the upper nuts to 47 N.m (35 ft lbs).
3. Install the engine mount bracket to the oil pan.
4. Install the bolts which secure the engine mount bracket to the oil pan. Tighten the bracket bolts to 58 N.m (43 ft lbs).
5. Lower the vehicle.
6. Lower the engine.
7. Raise and suitably support the vehicle.
8. Install the right engine splash shield.
9. Install the right front wheel and tire.
10. Connect the three-way catalytic converter pipe to the right exhaust manifold.
11. Lower the vehicle.
12. Install the engine mount struts.
13. Install the throttle body air inlet duct.
14. Connect the battery ground cable.

Scheme 30

Scheme 31

1. Remove the bolt and the nut from the engine mount strut at the left engine mount strut bracket on the engine.
2. Remove the bolt, the nut, and the engine wiring harness retainer from the engine mount strut at the engine mount strut bracket on the upper radiator support.
3. Remove the engine mount strut.
4. Inspect the rubber in the engine mount strut for the following conditions: Hardness Splitting Cracking

1. Install the engine mount strut.
2. Install the engine wiring harness retainer, the bolt, and the nut to the engine mount strut at the engine mount strut bracket on the upper radiator support. Tighten the engine mount strut bolt to 48 N.m (35 ft lbs).
3. Install the bolt and the nut to the engine mount strut at the left engine mount strut bracket on the engine. Tighten the engine mount strut nut to 48 N.m (35 ft lbs).

Scheme 32

Scheme 33

1. Remove the bolt and the nut from the engine mount strut at the right engine mount strut bracket on the engine.
2. Remove the bolt and the nut from the engine mount strut at the engine mount strut bracket on the upper radiator support.
3. Remove the engine mount strut.
4. Inspect the rubber in the engine mount strut for the following conditions: Hardness Splitting Cracking

1. Install the engine mount strut.
2. Install the bolt and the nut to the engine mount strut at the engine mount strut bracket on the upper radiator support. Tighten the engine mount strut bolt to 48 N.m (35 ft lbs).
3. Install the bolt and the nut to the engine mount strut at the right engine mount strut bracket on the engine. Tighten the engine mount strut nut to 48 N.m (35 ft lbs).

Scheme 34

Scheme 35

1. Remove the engine mount strut from the left engine mount strut bracket.
2. Remove the engine exhaust crossover pipe.
3. Remove the thermostat housing.
4. Remove the engine mount strut bracket bolts from the left engine mount strut bracket to the cylinder head.
5. Remove the left engine mount strut bracket.

1. Install the left engine mount strut bracket.
2. Install the engine mount strut bracket bolts through the engine mount strut bracket to the cylinder head. Tighten the engine mount strut bracket bolts to N.m (52 ft lbs).
3. Install the thermostat housing.
4. Install the engine exhaust crossover pipe.
5. Install the engine mount strut to the left engine mount strut bracket.

Scheme 36

Scheme 37

Scheme 38

1. Disconnect the battery ground (negative) cable.
2. Remove the right engine mount strut from the right engine mount strut bracket. Refer to «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. If equipped with oil cooler, remove the oil cooler pipe bracket bolt from the right engine mount strut bracket.
4. Reposition the air conditioning compressor.
5. Remove the vertical bolt from the right engine mount strut bracket.
6. Remove the right engine mount strut bracket.

1. Position the right engine mount strut bracket over the pin locator.
2. Install the vertical bolt through the right engine mount strut bracket to the cylinder head. Tighten the engine mount strut bracket bolt to 50 N.m (37 ft lbs).
3. Install the air conditioning compressor.
4. If equipped with oil cooler, install the oil cooler pipe bracket bolt to the right engine mount strut bracket. Tighten the oil cooler pipe bracket bolt to 10 N.m (89 in lbs).
5. Install the right engine mount strut to the right engine mount strut bracket.
6. Connect the battery ground (negative) cable.

Scheme 39

Scheme 40

1. Remove the engine mount strut from the engine mount strut bracket at the upper radiator support. Refer to «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) or «Engine Mount Strut (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
2. Remove the horizontal bolt from the engine mount strut bracket.
3. Remove the vertical bolts from the engine mount strut bracket.
4. Remove the engine mount strut bracket from the upper radiator support.

1. Position the engine mount strut bracket over the upper radiator support. Make sure that the engine mount strut bracket and the engine mount strut are aligned to the proper holes of the upper radiator support.
2. Install the vertical bolts (2) to the engine mount strut bracket. Tighten the engine mount strut bracket bolts to 28 N.m (21 ft lbs).
3. Install the horizontal bolt (1) to the engine mount strut bracket. Tighten the engine mount strut bracket bolt to 28 N.m (21 ft lbs).
4. Install the engine mount strut to the engine mount strut bracket at the upper radiator support.

Scheme 41

Scheme 42

Scheme 43

Scheme 44

Scheme 45

1. Raise and suitably support the vehicle.
2. Remove the oil filter. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Remove the oil filter bypass hole plug.
4. Insert a flat bladed tool into the oil filter bypass hole and force the bypass valve (1) out.
5. Remove the oil filter bypass valve.
6. If necessary, remove the oil filter fitting.

1. Install the oil filter fitting. Tighten the oil filter fitting to 39 N.m (29 ft lbs).
2. Install the oil filter bypass valve.
3. Install the oil filter bypass valve (1) to the proper depth.
4. Install the oil filter bypass hole plug. Tighten the oil filter fitting to 19 N.m (14 ft lbs).
5. Install the oil filter.
6. Lower the vehicle.
7. Add engine oil as required.

Scheme 46

1. Remove the spark plug wire from the number 6 cylinder spark plug.
2. Remove the oil level indicator.
3. Remove the oil level indicator tube bracket bolt.
4. Remove the oil level indicator tube.

1. Clean the oil level indicator tube.
2. Apply sealant around the oil level indicator tube 12.7 mm (0.50 in) below the bead. Use GM sealant P/N 12345739 or the equivalent.
3. Install the oil level indicator tube into the engine block.
4. Install the bolt to the oil level indicator tube bracket.
5. Install the oil level indicator tube bolt. Tighten the bolt to 25 N.m (18 ft lbs).
6. Install the oil level indicator.
7. Install the number 6 spark plug wire to the spark plug.

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

1. Disconnect the negative battery cable.
2. Remove the vacuum hoses from the following: Fuel pressure regulator Evaporative emissions (EVAP) canister purge valve Manifold vacuum source Brake booster Heater and air conditioning source
3. Disconnect the electrical connectors from the following: Exhaust gas recirculation (EGR) valve Mass air flow (MAF) sensor Intake air temperature (IAT) sensor Idle air control (IAC) valve Throttle position (T/P) sensor Evaporative emission (EVAP) canister purge valve
4. Remove the air cleaner intake duct.
5. Drain the cooling system.
6. Remove the accelerator control and cruise control cables with bracket from the throttle body.
7. Remove the left side spark plug wires from the spark plugs.
8. Remove the following wiring harnesses from the retainers: Camshaft position (CMP) sensor wiring harness Left side spark plug wire harness Engine wiring harness
9. Remove the thermostat bypass pipe coolant hoses (3,4) from the throttle body.
10. Remove the ignition coil bracket with the coils.
11. Remove the EVAP canister purge valve.
12. Remove the manifold absolute pressure (MAP) sensor and the bracket.
13. Remove the exhaust gas recirculation (EGR) valve.
14. Remove the right upper intake manifold bolts and the studs.
15. Remove the left upper intake manifold bolts.
16. Remove the upper intake manifold.
17. Remove the upper intake manifold gasket.
18. If replacing the upper intake manifold, remove the throttle body.
19. Clean the upper intake gasket mating surfaces.

1. If removed, install the throttle body.
2. Install the upper intake manifold gasket.
3. Install the upper intake manifold.
4. Install the left upper intake manifold bolts.
5. Install the right upper intake manifold bolts and the studs. Tighten the bolts and the studs to 25 N.m (18 ft lbs).
6. Install the exhaust gas recirculation (EGR) valve.
7. Install the manifold absolute pressure (MAP) sensor bracket and the sensor.
8. Install the EVAP canister purge valve.
9. Install the ignition coil bracket with the coils.
10. Install the thermostat bypass pipe coolant hoses (3,4) to the throttle body.
11. Install the following wiring harnesses to the retainers: Engine wiring harness Left side spark plug wire harness Camshaft position (CMP) sensor wiring harness
12. Install the left side spark plug wires to the spark plugs.
13. Install the accelerator control and cruise control cables with bracket to the throttle body.
14. Install the air cleaner intake duct.
15. Connect the electrical connectors to the following: Evaporative emission (EVAP) canister purge valve Throttle position (T/P) sensor Idle air control (IAC) valve Intake air temperature (IAT) sensor Mass air flow (MAF) sensor Exhaust gas recirculation (EGR) valve
16. Install the vacuum hoses to the following: Heater and air conditioning source Brake booster Manifold vacuum source Evaporative emissions (EVAP) canister purge valve Fuel pressure regulator
17. Connect the negative battery cable.
18. Fill the cooling system.

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Scheme 58

Scheme 59

Scheme 60

Scheme 61

Scheme 62

Scheme 63

1. Disconnect the negative battery cable.
2. Remove the upper intake manifold. Refer to «Intake Manifold Replacement - Upper»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Remove the left valve rocker arm cover. Refer to «Valve Rocker Arm Cover (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Remove the right valve rocker arm cover. Refer to «Valve Rocker Arm Cover (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
5. Disconnect the engine coolant temperature (ECT) sensor electrical connector.
6. Disconnect and remove the fuel injector and the manifold absolute pressure (MAP) sensor wiring harnesses.
7. Remove the fuel pipe clip bolt.
8. Remove the fuel pipe clip.
9. Remove the fuel feed pipe from the fuel injector rail.
10. Remove the fuel return pipe from the fuel injector rail.
11. Remove the fuel injector rail. Refer to «FUEL RAIL & INJECTORS»(/chevrolet/impala/viii-1999-2006/remont/removal-installation/#how-to-overhaul-the-engine-controls-removal-installation__fuel-rail-injectors) .
12. Remove the power steering pump from the front engine cover and reposition.
13. Remove the heater inlet pipe with heater hose from the lower intake manifold and reposition.
14. Remove the radiator inlet hose from the engine.
15. Remove the thermostat bypass hose from the thermostat bypass pipe and lower intake manifold pipe.
16. Remove the lower intake manifold bolts.
17. Remove the lower intake manifold.
18. Remove the valve rocker arms and pushrods. Refer to «Valve Rocker Arm & Push Rod - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__valve-rocker-arm-push-rod) .
19. Remove the lower intake manifold gaskets and seals.
20. Clean the lower intake manifold gasket mating surfaces.
21. Remove and clean all the RTV sealant from the lower intake manifold and the engine block (1).
22. Remove the ECT sensor.
23. Remove the water outlet bolts.
24. Remove the water outlet.
25. Remove the thermostat.

Scheme 64

1. Install the thermostat.
2. Install the water outlet.
3. Install the water outlet bolts. Tighten the bolts to 25 N.m (18 ft lbs).
4. Install the ECT sensor. Tighten the sensor to 23 N.m (17 ft lbs).
5. Apply 8-12 mm (0.08-0.11 in) bead of RTV Sealer, GM P/N 12345739 Canadian P/N 10953541 or equivalent, on each ridge where front and rear of the lower intake manifold contact the engine block (1).
6. Install the lower intake manifold gaskets. NOTE: When replacing lower intake manifold gasket, a revised intake manifold gasket has been introduced by manufacturer. This new design gasket helps resolve issues related to intake manifold oil/coolant leaks. The gasket requires a revised torque specification and procedure in addition to the use of NEW revised intake manifold bolts. Please review TSB ENGINE OIL OR COOLANT LEAK (INSTALL NEW INTAKE MANIFOLD GASKET) for complete information.
7. Install the valve rocker arms and pushrods.
8. Install the lower intake manifold.
9. Apply sealant, GM P/N 12345382 Canadian P/N 10953489 to the threads of the bolts. NOTE: An oil leak may result if the vertical bolts are not tightened before the diagonal bolts.
10. Install the lower intake manifold bolts. Please review TSB ENGINE OIL OR COOLANT LEAK (INSTALL NEW INTAKE MANIFOLD GASKET) for complete information.
11. Install the thermostat bypass hose to the thermostat bypass pipe and lower intake manifold pipe.
12. Install the radiator inlet hose to the engine.
13. Install the heater inlet pipe and heater hose to the lower intake manifold.
14. Install the power steering pump to the front engine cover.
15. Install the fuel injector rail.
16. Install the fuel return pipe to the fuel injector rail.
17. Install the fuel feed pipe to the fuel injector rail.
18. Install the fuel pipe clip.
19. Install the fuel pipe clip bolt. Tighten the bolt to 8 N.m (71 in lbs).
20. Install and connect the fuel injector and the MAP sensor wiring harnesses.
21. Connect the ECT sensor electrical connector.
22. Install the right valve rocker arm cover.
23. Install the left valve rocker arm cover.
24. Install the upper intake manifold.
25. Connect the negative battery cable.
26. Inspect for leaks.

Scheme 65

1. Remove the vacuum hoses (1) from the fuel pressure regulator (3) and positive crankcase ventilation (PCV) valve (2).
2. Remove the PCV valve (2).

1. Install the PCV valve (2).
2. Install the vacuum hoses (1) to the fuel pressure regulator (3) and the PCV valve (2).

1. Drain the cooling system.
2. Remove the left spark plug wires.
3. Remove the right engine mount strut at the engine. Refer to «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Remove the thermostat bypass hose and pipe.
5. Remove the positive crankcase ventilation (PCV) valve from the left valve rocker arm cover.
6. Remove the left valve rocker arm cover bolts.
7. Remove the left valve rocker arm cover.
8. Remove the left valve rocker arm cover gasket.
9. Clean the valve rocker arm cover.
10. Clean the valve rocker arm cover gasket mating surfaces.

Scheme 66

1. Install a new left valve rocker arm cover gasket to the valve rocker arm cover. Important: Apply sealant GM P/N 12345739 or equivalent at the cylinder head to lower intake manifold joint.
2. Apply sealant at the cylinder head to lower intake manifold joint at the rear of the lower intake manifold (1). Important: Apply sealant GM P/N 12345739 or equivalent at the cylinder head to lower intake manifold joint.
3. Apply sealant at the cylinder head to lower intake manifold joint at the front of the lower intake manifold (1).
4. Install the left valve rocker arm cover.
5. Install the valve rocker arm cover bolts. Tighten the bolts to 10 N.m (89 in lbs).
6. Install the PCV valve to the left valve rocker arm cover.
7. Install the thermostat bypass hose and pipe.
8. Install the right engine mount strut.
9. Install the left spark plug wires.
10. Fill the cooling system.

1. Disconnect the negative battery cable.
2. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Remove the generator.
4. Remove the generator bracket.
5. Remove the right spark plug wires.
6. Disconnect the vacuum hoses from the EVAP purge valve.
7. Remove the EVAP purge valve.
8. Remove the ignition coil bracket with the coils.
9. Remove the Ignition coil bracket studs.
10. Remove the vacuum hose from the grommet in the right valve rocker arm cover.
11. Remove the right valve rocker arm cover bolts.
12. Remove the right valve rocker arm cover.
13. Remove the right valve rocker arm cover gasket.
14. Clean the valve rocker arm cover gasket mating surfaces.

1. Install a new right valve rocker arm cover gasket to the valve rocker arm cover. Important: Apply sealant GM P/N 12345739, (Canadian P/N 10953472) or equivalent at the cylinder head to lower intake manifold joint.
2. Apply sealant at the cylinder head to lower intake manifold joint at the rear of the lower intake manifold (1). Important: Apply sealant GM P/N 12345739, (Canadian P/N 10953472) or equivalent at the cylinder head to lower intake manifold joint.
3. Apply sealant at the cylinder head to lower intake manifold joint at the rear of the lower intake manifold (1).
4. Install the right valve rocker arm cover.
5. Install the valve rocker arm cover bolts. Tighten the bolts to 10 N.m (89 in lbs).
6. Install the vacuum hose to the grommet in the right valve rocker arm cover.
7. Install the Ignition coil bracket studs.
8. Install the ignition coil bracket with coils.
9. Install the EVAP purge valve.
10. Connect the vacuum hoses to the EVAP purge valve.
11. Install the right spark plug wires.
12. Install the generator bracket.
13. Install the generator.
14. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
15. Connect the negative battery cable.

Valve Rocker Arm & Push Rod - Replacement

Tools Required

J 36660-A Torque Angle Meter

Scheme 67

1. Remove the valve rocker arm cover. Refer to «Valve Rocker Arm Cover (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) or «Valve Rocker Arm Cover (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
2. Remove the rocker arm bolts.
3. Remove the valve rocker arms and the pushrods.

Scheme 68

1. Coat the ends of the push rods using prelube GM P/N 1052365 or the equivalent. Important: The intake valve push rods measure 144 mm (5.75 in) in length, (yellow).
2. Install the push rods in their original location. The exhaust valve push rods measure 152.5 mm (6.0 in) in length, (green).
3. Coat the rocker arm friction surfaces using prelube GM P/N 1052365 or the equivalent.
4. Install the valve rocker arm bolts. Tighten the bolts to 19 N.m (14 ft lbs). Use the J 36660-A to rotate the bolts an additional 30 degrees.
5. Install the valve rocker arm cover.

Valve Stem Oil Seal & Valve Spring - Replacement

Tools Required

1. J 22794 Spark Plug Port Adapter
2. J 38606 Valve Spring Compressor

Important

1. Before you remove the valve locks, rotate the engine so that the piston in the cylinder you are working on is at (TDC) top dead center. This will eliminate the possibility of the valve accidentally falling inside the cylinder.
2. Break the spark plug loose, and clean any dirt and debris from the spark plug recess area before removing.

Scheme 69

Scheme 70

1. Remove the spark plug.
2. Remove the rocker arm. Refer to «Valve Rocker Arm & Push Rod - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__valve-rocker-arm-push-rod) .
3. Install the J 22794 into the spark plug port. Apply compressed air in order to hold the valves in place.
4. Install the J 38606 on the valve spring.
5. Compress the valve spring with the J 38606 .
6. Remove the valve locks.
7. Remove the valve cap.
8. Remove the valve spring.
9. Inspect the valve spring for damage. Replace the spring if it is damaged.
10. Remove the spring seat/valve stem oil seal.

1. Install the valve stem oil seal/spring seat. Use a suitable driver. Press over the valve guide boss.
2. Install the valve spring.
3. Install the valve cap.
4. Compress the valve spring with the J 38606 .
5. Install the valve locks. If necessary, hold the valve locks in place with grease.
6. Release the valve spring using the J 38606 .
7. Make sure that the valve locks are seated.
8. Install the valve rocker arm. Refer to «Valve Rocker Arm & Push Rod - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__valve-rocker-arm-push-rod) .
9. Release the air pressure and remove the J 22794 .
10. Install the spark plug.

1. Remove the valve rocker arm cover. Refer to «Valve Rocker Arm Cover (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) or «Valve Rocker Arm Cover (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
2. Remove the lower intake manifold. Refer to «Intake Manifold (Lower) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Remove the valve rocker arms and pushrods. Refer to «Valve Rocker Arm & Push Rod - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__valve-rocker-arm-push-rod) .
4. Remove the lifter guide bolts.
5. Remove the lifter guide. Important: Place the valve train parts in a rack in order to ensure that they are installed in the same location from which they were removed.
6. Remove the lifters.

Scheme 71

1. Coat the valve lifters using prelube GM P/N 1052367 Canadian P/N 992869 or the equivalent.
2. Install the valve lifters in their original locations.
3. Install the lifter guide.
4. Apply threadlock GM P/N 12345382 Canadian P/N 10953489 or the equivalent to the lifter guide bolts and install the bolts. Tighten the bolts to 10 N.m (89 in lbs).
5. Install the valve rocker arms and pushrods.
6. Install the lower intake manifold.
7. Install the engine left side valve rocker arm cover.
8. Inspect for leaks.

Crankshaft Balancer - Replacement

Tools Required

1. J 24420-C Crankshaft Balancer Remover
2. J 29113 Crankshaft Balancer Installer
3. J 37096 Flywheel Holder

Note. The inertial weight section of the crankshaft balancer is assembled to the hub with a rubber type material. The correct installation procedures (with the proper tool) must be followed or movement of the inertial weight section of the hub will destroy the tuning of the crankshaft balancer.

Scheme 72

1. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
2. Raise and support the vehicle.
3. Remove the right front tire and wheel.
4. Remove the right engine splash shield.
5. Support the frame with jackstands.
6. Loosen the left side and remove the right side frame bolts.
7. Use the jackstands to lower the right side of the frame.
8. Remove the torque converter covers.
9. Install the J 37096 to prevent the flywheel from rotating.
10. Remove the crankshaft balancer bolt and the washer.
11. Use the J 24420-C to remove the crankshaft balancer.

Scheme 73

1. Apply sealant GM P/N 12345739, (Canadian P/N 10953472) or equivalent to the keyway of the balancer.
2. Use the J 29113 to install the crankshaft balancer.
3. Remove the J 29113 from the crankshaft balancer.
4. Install the J 37096 to prevent the flywheel from rotating.
5. Install the crankshaft balancer washer and the bolt. Tighten the bolt to 103 N.m (76 ft lbs).
6. Remove the J 37096 from the flywheel.
7. Install the torque converter covers.
8. Raise the frame to the original position.
9. Install the frame bolts.
10. Remove the jackstands.
11. Install the right engine splash shield.
12. Install the right front tire and wheel.
13. Lower the vehicle.
14. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
15. Perform a CKP system variation learn procedure. Refer to «CRANKSHAFT POSITION SENSOR»(/chevrolet/impala/viii-1999-2006/remont/removal-installation/#how-to-overhaul-the-engine-controls-removal-installation) .

Oil Pan Replacement

Tools Required

1. J 28467-360 Engine Support Fixture
2. J 28467-90A Engine Support Fixture Adapter
3. J 36462-A Engine Support Adapter Leg
4. J 39505 Torque Wrench Adapter

Scheme 74

Scheme 75

1. Disconnect the battery ground cable.
2. Remove the engine mount struts from the engine. Refer to «Engine Mount Strut (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) and «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Install the J 28467-360 .
4. Raise and suitably support the vehicle.
5. Disconnect the A/C compressor mounting bolts. Reposition and secure the A/C compressor.
6. Disconnect the three-way catalytic converter pipe from the right exhaust manifold.
7. Drain the engine oil. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
8. Disconnect the oil level sensor wiring harness connection.
9. Remove the starter motor.
10. Remove the transaxle brace from the oil pan.
11. Loosen the transaxle mount lower nuts.
12. Remove the engine mount lower nuts. Refer to «Engine Mount Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
13. Lower the vehicle.
14. Use the J 28467-360 in order to raise the engine.
15. Raise and suitably support the vehicle.
16. Remove the engine mount bracket with the engine mount from the oil pan. Refer to «Engine Mount Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
17. Disconnect the right lower ball joint from the steering knuckle.
18. Disconnect the right outer tie rod from the steering knuckle. Refer to «TIE ROD END REPLACEMENT - OUTER»(/chevrolet/impala/viii-1999-2006/remont/manual-power-steering/#power-rack-pinion-steering-system__tie-rod-end-replacement-outer) .
19. Remove the right side frame bolts.
20. Loosen the left side frame bolts.
21. Use the J 39505 in order to remove the right oil pan side bolts.
22. Remove the left oil pan side bolts.
23. Remove the oil pan retaining bolts.
24. Remove the oil pan.
25. Remove the oil pan gasket.
26. Clean the oil pan and the engine block gasket surface.

1. Apply sealant at the rear main bearing cap and the engine block (1).
2. Install the oil pan gasket.
3. Install the oil pan. Install the oil pan retaining bolts.
4. Install the oil pan retaining bolts. Tighten the oil pan retaining bolts to 25 N.m (18 ft lbs).
5. Install the left oil pan side bolts. Tighten the oil pan side bolts to 50 N.m (37 ft lbs).
6. Use the J 39505 in order to install the right oil pan side bolts. Tighten the oil pan side bolts to 50 N.m (37 ft lbs).
7. Tighten the left side frame bolts. Tighten the bolts to 180 N.m (133 ft lbs).
8. Install the right side frame bolts. Tighten the bolts to 180 N.m (133 ft lbs).
9. Connect the right lower ball joint to the steering knuckle.
10. Connect the right outer tie rod to the steering knuckle.
11. Install the engine mount bracket with the engine mount to oil pan.
12. Lower the vehicle.
13. Use the J 28467-360 in order to lower the engine.
14. Raise and suitably support the vehicle.
15. Install the transaxle mount lower nuts.
16. Install the engine mount lower nuts. Refer to «Engine Mount Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
17. Install the transaxle brace to the oil pan.
18. Install the starter motor.
19. Install the oil level sensor wiring harness connection.
20. Install the three-way catalytic converter pipe to the right exhaust manifold.
21. Install the A/C compressor.
22. Lower the vehicle.
23. Remove J 28467-360, J 36462-A and J 28467-90A .
24. Install the engine mount struts to the engine. Refer to «Engine Mount Strut (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) and «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
25. Fill the engine with new engine oil.
26. Connect the battery ground cable.

Scheme 76

1. Raise and support the vehicle.
2. Disconnect the engine oil pressure switch electrical connector.
3. Remove the oil pressure switch.

1. Install the engine oil pressure switch. Tighten the switch to 16 N.m (12 ft lbs)
2. Connect the engine oil pressure switch electrical connector.
3. Lower the vehicle.

Scheme 77

Scheme 78

1. Raise and support the vehicle.
2. Remove the engine oil drain plug in order to drain the engine oil.
3. Disconnect the oil level sensor electrical connector.
4. Remove the bolt from the oil level sensor.
5. Remove the oil level sensor.

1. Install the oil level sensor.
2. Install the oil level sensor bolt. Tighten the bolt to 9 N.m (80 in lbs).
3. Connect the oil level sensor electrical connector.
4. Install the engine oil drain plug. Tighten the plug to 30 N.m (22 ft lbs).
5. Lower the vehicle.
6. Fill the crankcase with engine oil.

Scheme 79

1. Remove the oil pan. Refer to «Oil Pan Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__oil-pan-replacement) .
2. Remove the oil pump Refer to «Oil Pump Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Remove the crankshaft oil deflector nuts.
4. Remove the crankshaft oil deflector.

1. Install the crankshaft oil deflector.
2. Install the crankshaft oil deflector nuts. Tighten the nuts to 25 N.m (18 ft lbs).
3. Install the oil pump drive and the oil pump.
4. Install the oil pan.

1. Remove the oil pan. Refer to «Oil Pan Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__oil-pan-replacement) .
2. Remove the oil pump bolt.
3. Remove the oil pump and the driveshaft.
4. Inspect the driveshaft and the oil pump. Refer to «OIL PUMP -- CLEANING & INSPECTION»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-unit-repair) .

1. Install the oil pump and the driveshaft. Install the oil pump bolt. Tighten the bolt to 41 N.m (30 ft lbs).
2. Install the oil pan.

1. Remove the upper intake manifold. Refer to «Intake Manifold (Upper) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
2. Remove the fuel feed and the return pipe from the fuel injector rail.
3. Remove the oil pump drive bolt.
4. Remove the oil pump drive clamp.
5. Remove the oil pump drive.
6. Remove the oil pump drive seal.

1. Install the oil pump drive seal. Coat the seal or bore in the engine block with engine oil.
2. Install the oil pump drive.
3. Install the oil pump drive clamp bolt. Tighten the bolt to 36 N.m (27 ft lbs).
4. Install the fuel feed and the return pipe to the fuel injector rail.
5. Install the upper intake manifold.

Crankshaft Front Oil Seal - Replacement

Tools Required

J 35468 Crankshaft Front Oil Seal Installer

1. Remove the crankshaft balancer. Refer to «Crankshaft Balancer - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__crankshaft-balancer-replacement) .
2. Use a suitable tool in order to pry out the crankshaft front oil seal. Refer to the instructions supplied with the replacement part.
3. Inspect the crankshaft, the crankshaft balancer and the engine front cover for wear and/or damage. Replace or repair the crankshaft, the crankshaft balancer and/or engine front cover as necessary.

Scheme 80

1. Lubricate the crankshaft front oil seal with engine oil in order to make installation easier. Install the crankshaft front oil seal using the J 35468 . Make sure that the crankshaft front oil seal lip faces the engine.
2. Make sure the crankshaft front oil seal is installed flush to the engine front cover (1).
3. Install the crankshaft balancer.
4. Inspect for leaks.

Scheme 81

Scheme 82

1. Disconnect the battery ground (negative) cable.
2. Drain the engine coolant from the cooling system.
3. Drain the engine oil. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Remove the oil pan. Refer to «Oil Pan Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__oil-pan-replacement) .
5. Remove the coolant recovery reservoir.
6. Remove the crankshaft balancer. Refer to «Crankshaft Balancer - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__crankshaft-balancer-replacement) .
7. Remove the drive belt tensioner. Refer to «Drive Belt Tensioner Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
8. Remove the power steering pump with the lines. Reposition the power steering pump.
9. Disconnect the thermostat bypass pipe from the engine front cover.
10. Disconnect the radiator outlet hose from the timing cover.
11. Remove the coolant pump from the engine front cover.
12. Remove the lower crankshaft position sensor wiring harness bracket from the engine front cover
13. Remove the engine front cover bolts (1, 2 and 3).
14. Remove the engine front cover.
15. Remove the engine front cover gasket.
16. Inspect the engine front cover for damage to the engine front cover, crankshaft front oil seal or the gasket sealing surface. Refer to «ENGINE FRONT COVER -- CLEANING & INSPECTION»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-unit-repair) .
17. If replacing the engine front cover, remove the drive belt shield.
18. Remove the crankshaft position sensor from the engine front cover. Refer to «CRANKSHAFT POSITION SENSOR»(/chevrolet/impala/viii-1999-2006/remont/removal-installation/#how-to-overhaul-the-engine-controls-removal-installation) .

Scheme 83

1. If removed, install the crankshaft position sensor to the engine front cover.
2. If removed, install the drive belt shield. Install the drive belt shield bolt. Tighten the drive belt shield bolt to 10 N.m (89 in lbs).
3. Install the engine front cover gasket.
4. Install the engine front cover.
5. Install the engine front cover bolts (3). Tighten the bolts (3) to 55 N.m (41 ft lbs).
6. Install the engine front cover bolt (1). Tighten the bolt (1) to 47 N.m (35 ft lbs).
7. Install the engine front cover bolts (2). Tighten the bolts (2) to 21 N.m (15 ft lbs).
8. Install the lower crankshaft position sensor wiring harness bracket to the engine front cover
9. Install the coolant pump to the engine front cover.
10. Connect the radiator outlet hose to the timing cover.
11. Connect the thermostat bypass pipe to the engine front cover.
12. Install the power steering pump with the lines.
13. Install the drive belt tensioner. Refer to «Drive Belt Tensioner Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
14. Install the crankshaft balancer. Refer to «Crankshaft Balancer - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__crankshaft-balancer-replacement) .
15. Install the oil pan. Refer to «Oil Pan Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__oil-pan-replacement) .
16. Fill the engine with new engine oil.
17. Fill the cooling system with engine coolant.
18. Connect the battery ground (negative) cable.
19. Perform a CKP system variation learn procedure. Refer to «CRANKSHAFT POSITION SENSOR»(/chevrolet/impala/viii-1999-2006/remont/removal-installation/#how-to-overhaul-the-engine-controls-removal-installation) .

Timing Chain & Sprockets - Replacement

Tools Required

1. J 5825-A Crankshaft Sprocket Remover
2. J 38612 Crankshaft Sprocket Installer

Scheme 84

Scheme 85

Scheme 86

Scheme 87

Scheme 88

1. Remove the engine front cover. Refer to «Engine Front Cover - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
2. Rotate the crankshaft until the timing marks in the following locations are aligned: The camshaft alignment pin (4). The timing chain dampener (1) to the crankshaft sprocket (2).
3. Remove the camshaft sprocket bolt.
4. Remove the camshaft sprocket with the timing chain.
5. Use the J 5825-A in order to remove the crankshaft sprocket.
6. Remove the timing chain dampener bolts.
7. Remove the timing chain dampener.
8. If necessary remove the camshaft thrust plate bolts.
9. Remove the camshaft thrust plate.
10. Clean and inspect the timing chain and gears. Refer to «Engine Front Cover - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .

1. If removed install the camshaft thrust plate.
2. Install the camshaft thrust plate bolts. Tighten the bolts to 10 N.m (89 in lbs).
3. Use the J 38612 to install the crankshaft sprocket.
4. Remove the J 38612 .
5. Install the timing chain dampener to the block.
6. Install the timing chain onto the camshaft gear.
7. Hold the camshaft sprocket with the chain hanging down, and install the chain to the crankshaft gear.
8. Align the crankshaft timing mark (2) to the timing mark on the bottom of the timing chain dampener (1).
9. Align the timing mark on the camshaft gear, center line of the locator hole (4), with the timing mark on the top of the chain dampener (3).
10. Align the dowel in the camshaft with the dowel hole in the camshaft sprocket (1). Important: Draw the camshaft sprocket onto the camshaft using the mounting bolt.
11. Install the camshaft sprocket bolt. Tighten the bolt to 140 N.m (103 ft lbs).
12. Coat the crankshaft and camshaft sprocket with engine oil.
13. Install the engine front cover. Refer to «Engine Front Cover - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .

Cylinder Head (Left) - Replacement

Tools Required

J 36660-A Torque Angle Meter

Scheme 89

1. Raise and support the vehicle.
2. Drain the cooling system.
3. Drain the engine oil. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Lower the vehicle.
5. Remove the lower intake manifold. Refer to «Intake Manifold (Lower) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
6. Remove the valve rocker arms and the pushrods. Refer to «Valve Rocker Arm & Push Rod - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__valve-rocker-arm-push-rod) .
7. Remove the exhaust crossover pipe.
8. Remove the right engine mount strut bracket. Refer to «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
9. Remove the oil level indicator tube. Refer to «Oil Level Indicator & Tube Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
10. Remove the left spark plug wires from the spark plugs.
11. Remove the left spark plugs.
12. Remove the left exhaust manifold.
13. Remove and discard the left cylinder head bolts.
14. Remove the left cylinder head.
15. Remove the left cylinder head gasket.
16. Clean and inspect the cylinder head gasket mating surfaces.
17. Clean and inspect the cylinder head. Refer to «CYLINDER HEAD -- CLEANING & INSPECTION»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-unit-repair__cylinder-head-cleaning-inspection) .

1. Install a new left cylinder head gasket.
2. Install the left cylinder head over the locator pins and over the gasket.
3. Install NEW cylinder head bolts. Tighten the bolts in sequence to 60 N.m (44 ft lbs). Using the J 36660-A , rotate the bolts an additional 95 degrees.
4. Install the left exhaust manifold.
5. Install the left spark plugs.
6. Install the left spark plug wires to the spark plugs.
7. Install the oil level indicator tube. Refer to «Oil Level Indicator & Tube Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
8. Install the right engine mount strut bracket. Refer to «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
9. Install the exhaust crossover pipe.
10. Install the valve rocker arms and pushrods. Refer to «Valve Rocker Arm & Push Rod - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__valve-rocker-arm-push-rod) .
11. Install the lower intake manifold. Refer to «Intake Manifold (Lower) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
12. Fill the crankcase with engine oil. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
13. Fill the cooling system.
14. Inspect for leaks.

Cylinder Head Replacement - Right

Tools Required

J 36660-A Torque Angle Meter

Scheme 90

1. Raise and support the vehicle.
2. Drain the cooling system.
3. Drain the engine oil. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Lower the vehicle.
5. Remove the lower intake manifold. Refer to «Intake Manifold (Lower) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
6. Remove the valve rocker arms and pushrods. Refer to «Valve Rocker Arm & Push Rod - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__valve-rocker-arm-push-rod) .
7. Remove the exhaust crossover pipe.
8. Remove the right spark plug wires from the spark plugs.
9. Remove the fuel line bracket bolt/stud and bracket.
10. Remove the generator.
11. Remove the right spark plugs.
12. Remove the right exhaust manifold.
13. Remove the right cylinder head bolts.
14. Remove the right cylinder head.
15. Remove the right cylinder head gasket.
16. Clean and inspect the cylinder head gasket mating surfaces.
17. Clean and inspect the cylinder head. Refer to «CYLINDER HEAD -- CLEANING & INSPECTION»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-unit-repair__cylinder-head-cleaning-inspection) .

1. Install a new right cylinder head gasket.
2. Install the right cylinder head over the locator pins and over the gasket.
3. Install NEW cylinder head bolts Tighten the bolts in sequence to 60 N.m (44 ft lbs). Using the J 36660-A, rotate the bolts an additional 95 degrees. see scheme 118
4. Install the right exhaust manifold.
5. Install the right spark plugs.
6. Install the generator.
7. Install the fuel line bracket.
8. Install the right spark plug wires to the spark plugs.
9. Install the exhaust crossover pipe.
10. Install the pushrods and valve rocker arms. Refer to «Valve Rocker Arm & Push Rod - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__valve-rocker-arm-push-rod).
11. Install the lower intake manifold. Refer to «Intake Manifold (Lower) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle).
12. Fill the crankcase with engine oil. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle).
13. Install the fuel line bracket bolt and stud. Tighten the bolt and stud to 20 N.m (15 ft lbs).
14. Fill the cooling system.
15. Inspect for leaks.

Engine Flywheel Replacement

Tools Required

J 37096 Flywheel Holder

1. Remove the automatic transaxle.
2. Use the J 37096 to secure the flywheel in order to prevent rotation.
3. Loosen the 6 engine flywheel bolts.
4. Remove 5 of the 6 flywheel bolts leaving 1 bolt at the top of the crankshaft rotation.
5. Grip the flywheel and remove the remaining bolt. Do not drop the flywheel when removing the final bolt.
6. Remove the engine flywheel retainer and the flywheel.
7. Clean the engine flywheel bolt threads and bolt holes.

1. Install the flywheel and the flywheel retainer.
2. Install the flywheel bolts. Use the J 37096 to prevent flywheel rotation. Tighten the bolts to 71 N.m (52 ft lbs).
3. Install the automatic transaxle.

Crankshaft Rear Oil Seal - Replacement

Tools Required

J 34686 Rear Main Seal Installer

Scheme 91

1. Remove the engine flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-flywheel-replacement) . Important: Do not nick the crankshaft sealing surface when removing the seal.
2. Remove the crankshaft rear oil seal. 2.1. Insert a flat-bladed tool or similar tool through the dust lip at an angle. 2.2. Pry the crankshaft rear oil seal out by moving the handle of the tool towards the end of the crankshaft. 2.3. Repeat as necessary around the crankshaft rear oil seal.

1. Entirely coat the new crankshaft rear oil seal with engine oil.
2. Install the crankshaft rear oil seal onto the J 34686 .
3. Install the J 34686 onto the rear of the crankshaft. Hand tighten the screws in order to ensure the seal will be installed squarely over the crankshaft.
4. Install the seal to the crankshaft.
5. Tighten the wing nut on the J 34686 until it bottoms.
6. Remove the J 34686 from the crankshaft.
7. Install the engine flywheel.

Scheme 92

1. Remove the engine flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-flywheel-replacement) .
2. Remove the camshaft rear bearing hole plug.

1. Coat the camshaft rear bearing hole plug with sealer GM P/N 12377901 or equivalent.
2. Install the camshaft rear bearing hole plug.
3. Ensure that the camshaft rear bearing plug is installed to specifications.
4. Install the engine flywheel.

Scheme 93

1. Disconnect the negative battery cable.
2. Drain the cooling system.
3. Drain the engine oil. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
4. Remove the air cleaner assembly.
5. Remove the hood.
6. Remove the engine mount struts. Refer to «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
7. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
8. Disconnect the following electrical connectors: Knock sensor Camshaft position (CMP) sensor Crankshaft position (CKP) sensor Heated oxygen (HO2S) sensor Manifold absolute pressure (MAP) sensor Exhaust gas recirculation (EGR) valve Evaporative emissions (EVAP) canister purge solenoid Throttle position (T/P) sensor Idle air control (IAC) valve Ignition coil Body wiring harness-to-engine harness
9. Raise and support the vehicle.
10. Remove the 3-way catalytic converter pipe from the right exhaust manifold.
11. Remove the engine wiring harness grounds from the transaxle.
12. Remove the engine mount lower nuts.
13. Remove the torque converter covers.
14. Remove the starter motor.
15. Remove the A/C compressor. DO NOT discharge the A/C system. Support the compressor.
16. Remove the torque converter bolts.
17. Remove the transaxle brace.
18. Remove the lower transaxle-to-engine bolt (6) and stud (1).
19. Remove the radiator outlet hose from the engine.
20. Lower the vehicle and support the transaxle.
21. Remove the accelerator control and the cruise control cable with the bracket from the throttle body.
22. Remove the heater outlet and inlet hoses from the engine.
23. Remove the vacuum hoses from the upper intake manifold.
24. Remove the brake booster vacuum hose from the upper intake manifold.
25. Remove the fuel lines from the fuel rail.
26. Remove the radiator inlet hose from the engine.
27. Remove the power steering pump and reposition.
28. Install the engine lifting device to the engine.
29. Remove the upper transaxle-to-engine bolts (3,4,5) and stud (2).
30. Remove the engine from the vehicle.
31. Remove the flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-flywheel-replacement) .
32. Install the engine to the engine stand.
33. Remove the generator and the generator bracket.
34. Remove the engine mount bracket. Refer to «Engine Mount Bracket - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-mount-bracket-replacement) .
35. Remove the drive belt tensioner. Refer to «Drive Belt Tensioner Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
36. Remove the ignition control module.

1. Install the ignition control module.
2. Install the drive belt tensioner. Refer to «Drive Belt Tensioner Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
3. Install the engine mount bracket. Refer to «Engine Mount Bracket - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-mount-bracket-replacement) .
4. Install the generator and the generator bracket.
5. Remove the engine from the engine stand.
6. Install the flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle__engine-flywheel-replacement) .
7. Install the engine to the vehicle.
8. Install the upper transaxle-to-engine bolts (3,4,5) and stud (2). Tighten the bolts (3,4,5) and the stud (2) to 75 N.m (55 ft lbs).
9. Remove the engine lifting device.
10. Install the power steering pump.
11. Install the radiator inlet hose to the engine.
12. Install the fuel lines to the fuel rail.
13. Install the brake booster vacuum hose to the upper intake manifold.
14. Install the vacuum hoses to the upper intake manifold.
15. Install the heater inlet and outlet hoses to the engine.
16. Install the accelerator control and the cruise control cable with the bracket to the throttle body.
17. Raise the vehicle and remove the transaxle support.
18. Install the radiator outlet hose to the engine.
19. Install the lower transaxle-to-engine bolt (6) and stud (1). Tighten the bolt (6) and the stud (1) to 75 N.m (55 ft lbs).
20. Install the transaxle brace.
21. Install the torque converter bolts.
22. Install the A/C compressor.
23. Install the starter motor.
24. Install the torque converter covers.
25. Install the engine mount lower nuts. Tighten the nuts to 43 N.m (32 ft lbs).
26. Install the engine wiring harness grounds to the transaxle.
27. Install the engine wiring harness ground nut to the transaxle stud. Tighten the nut to 35 N.m (26 ft lbs).
28. Install the 3-way catalytic converter pipe to the right exhaust manifold.
29. Lower the vehicle.
30. Connect the following electrical connectors: Body wiring harness-to-engine harness Ignition coil Idle air control (IAC) valve Throttle position (T/P) sensor Evaporative emissions (EVAP) canister purge solenoid Exhaust gas recirculation (EGR) valve Manifold absolute pressure (MAP) sensor Heated oxygen (HO2S) sensor Crankshaft position (CKP) sensor Camshaft position (CMP) sensor Knock sensor
31. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
32. Install the engine mount struts. Refer to «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
33. Install the hood.
34. Install the air cleaner assembly.
35. Connect the negative battery cable.
36. Fill the crankcase with engine oil. Refer to «Engine Oil & Oil Filter Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
37. Fill cooling system.
38. Check and fill the power steering system as necessary.
39. Perform a CKP system variation learn procedure. Refer to «CRANKSHAFT POSITION SENSOR»(/chevrolet/impala/viii-1999-2006/remont/removal-installation/#how-to-overhaul-the-engine-controls-removal-installation) .
40. Inspect for leaks.

1. Raise and suitably support the vehicle.
2. Position the oil drain pan under the engine oil drain plug.
3. Remove the engine oil pan drain plug.
4. Clean and inspect the engine oil pan drain plug, repair or replace if necessary.
5. Clean and inspect the engine oil pan drain plug sealing surface on the oil pan, repair or replace oil pan if necessary.
6. Remove the oil filter.
7. Clean and inspect the oil filter sealing area on the engine block, repair or replace if necessary.

1. Lightly oil the replacement oil filter gasket with clean oil.
2. Install the new oil filter. Tighten the new oil filter to 3/4 to 1 full turn, after the oil filter gasket contacts the oil filter mounting surface.
3. Install the engine oil pan drain plug. Tighten the engine oil pan drain plug to 25 N.m (18 ft lbs).
4. Remove the oil drain pan.
5. Lower the vehicle.
6. Fill the engine with new engine oil.
7. Start the engine.
8. Inspect for oil leaks after engine start up.
9. Turn off the engine and allow the oil a few minutes to drain back into the oil pan.
10. Remove the oil level indicator from the oil level indicator tube.
11. Clean off the indicator end of the oil level indicator with a clean paper towel or cloth.
12. Install the oil level indicator into the oil level indicator tube until the oil level indicator handle contacts the top of the oil level indicator tube.
13. Again, remove the oil level indicator from the oil level indicator tube keeping the tip of the oil level indicator down.
14. Check the level of the engine oil on the oil level indicator.
15. If necessary, readjust the oil level by adding or draining the engine oil.

Scheme 94

The crankcase ventilation system is used to consume crankcase vapors (1) in the combustion process instead of venting them to atmosphere. Fresh air from the throttle body is supplied to the crankcase, mixed with blow by gases and then passed through a positive crankcase ventilation (PCV) valve (3) into the intake manifold.

Scheme 95

The primary control is through the PCV valve (1) which meters the flow at a rate depending on inlet vacuum. To maintain idle quality, the PCV valve restricts the flow when inlet vacuum is high. If abnormal operating conditions arise, the system is designed to allow excessive amounts of blow by gases to back flow through the crankcase vent into the throttle body to be consumed by normal combustion.

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 backwards 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 rubbers (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.

Rotating The Engine For Service Access

Tools Required

J 41131 Engine Tilt Strap

1. Remove the throttle body air inlet duct.
2. Apply the parking brake.
3. Put the transaxle in the Neutral position.
4. Remove the engine mount strut bolts. Swing the engine mount struts aside. Refer to «Engine Mount Strut (Left) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) and «Engine Mount Strut (Right) - Replacement»(/chevrolet/impala/viii-1999-2006/remont/mechanical/#engine-mechanical-34l-v6-vin-e-on-vehicle) .
5. Install the J 41131 .
6. Rotate the engine forward for component access.

Scheme 96

Scheme 97

Scheme 98

Scheme 99

Scheme 100

See also:
• DIAGNOSTIC SYSTEM CHECK -- ENGINE CONTROLS
• CHECKING AFTERMARKET ACCESSORIES
• PISTON, CONNECTING ROD & BEARINGS -- CLEANING
• ENGINE BLOCK -- CLEANING & INSPECTION
• CYLINDER HEAD -- CLEANING & INSPECTION
• FUEL RAIL & INJECTORS
• CRANKSHAFT POSITION SENSOR
• TIE ROD END REPLACEMENT - OUTER
• OIL PUMP -- CLEANING & INSPECTION
• Symptoms - Engine Mechanical
• Engine Compression Test
• Oil Consumption Diagnosis
• Oil Leak Diagnosis
• Possible Causes For Leaks
• Engine Support Fixture
• Valve Rocker Arm & Push Rod - Replacement
• Oil Pan Replacement
• Crankshaft Balancer - Replacement
• Engine Flywheel Replacement
• Engine Mount Bracket - Replacement