Engine Mechanical - 4.3l Chevrolet Blazer S15 рестайлинг

Fastener Tightening Specifications

FASTENER TIGHTENING SPECIFICATIONS

Engine Mechanical Specifications

Engine Mechanical Specifications

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Diagnostic Starting Point - Engine Mechanical

Begin the system diagnosis by reviewing the DISASSEMBLED VIEWS , ENGINE COMPONENT DESCRIPTION , LUBRICATION DESCRIPTION and NEW PRODUCT INFORMATION and Drive Belt System Description . Reviewing the description and operation information 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 the DIAGNOSTIC SYSTEM CHECK before using the symptom tables, if applicable.
2. Review the system operations in order to familiarize yourself with the system functions. Refer to «DISASSEMBLED VIEWS»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) , «ENGINE COMPONENT DESCRIPTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) , «LUBRICATION DESCRIPTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) and «NEW PRODUCT INFORMATION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__new-product-information) and «Drive Belt System Description»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l__drive-belt-system-description) .

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

Intermittent

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

Symptom List

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

1. «Base Engine Misfire without Internal Engine Noises»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
2. «Base Engine Misfire with Abnormal Internal Lower Engine Noises»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
3. «Base Engine Misfire with Abnormal Valve Train Noise»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
4. «Base Engine Misfire with Coolant Consumption»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
5. «Base Engine Misfire with Excessive Oil Consumption»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
6. «Engine Compression Test»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l__engine-compression-test)
7. «Engine Noise on Start-Up, but Only Lasting a Few Seconds»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
8. «Upper Engine Noise, Regardless of Engine Speed»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
9. «Lower Engine Noise, Regardless of Engine Speed»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
10. «Engine Noise Under Load»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
11. «Engine Will Not Crank - Crankshaft Will Not Rotate»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)
12. «Oil Consumption Diagnosis»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l__oil-consumption-diagnosis)
13. «Oil Pressure Diagnosis and Testing»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l__oil-pressure-diagnosis-and-testing)
14. «Oil Leak Diagnosis»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)

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Engine Compression Test

1. Ensure that the vehicle batteries are in good condition, and fully charged.
2. Operate the vehicle until the engine is at normal operating temperature.
3. Disconnect the positive ignition coil wire plug from the ignition coil.
4. Disconnect the fuel injector electrical connector.
5. Remove all of the spark-plugs. NOTE: Do not insert objects into the throttle plate opening. Damage to the throttle body can result, requiring replacement of the throttle body assembly.
6. Block the throttle linkage wide-open.
7. Install the engine cylinder compression gage to the cylinder being tested.
8. Using the vehicle starter motor, rotate, or crank the engine for 4 compression strokes, or puffs, for the cylinder being tested. If the engine rotates for more than 4 compression strokes, test the cylinder again.
9. Record the compression reading.
10. Remove the engine cylinder compression gage from the cylinder being tested.
11. Repeat steps 8-11 for each additional cylinder. All cylinders must be tested to obtain valid test results.
12. Check the compression readings. Refer to «Engine Mechanical Specifications»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l__engine-mechanical-specifications) . Normal The compression builds up quickly and evenly to the specified compression. Leaking The compression is low on the first compression stroke. The compression builds up with the following strokes, but does not reach the specified compression.
13. If any cylinders have low compression, inject approximately 15 ml (1 oz) of engine oil into the cylinder through the spark plug hole.
14. Repeat steps 8-11 for all low compression cylinders.
15. Check the compression readings. Refer to «Engine Mechanical Specifications»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l__engine-mechanical-specifications) . Piston rings leaking Compression is low on the first compression stroke. The compression builds up on the following strokes, but does not reach normal. Compression improves considerably when you add oil. Valves leaking Compression is low on the first compression stroke. The compression does not build up on the following strokes, and does not reach normal. Compression does not improve much, if at all, when you add oil. Head gasket leaking Compression is low on the first stroke. The compression does not build up on the following strokes, and does not reach normal. Compression does not improve much, if at all, when you add oil. Adjacent cylinders have the same, or similar, low compression readings.
16. If one or more cylinders fails to meet the minimum specified compression, repair or replace all damaged or worn components and test the engine again.

Oil Consumption Diagnosis

Excessive oil consumption, not due to leaks, is the use of 1 liter (1 quart) of engine oil within 3,200 kilometers (2,000 miles). However, during initial engine break-in periods 4,828-6,437 kilometers (3,000-4,000 miles), oil consumption may exceed 1 liter (1 quart) or more. The causes of excessive oil consumption include the following conditions

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

Oil Pressure Diagnosis and Testing

1. With the vehicle on a level surface, allow adequate drain down time, 2-3 minutes, and measure for a low engine oil level. Add the recommended grade engine oil, and fill the crankcase until the oil level measures FULL on the oil level indicator.
2. Operate the engine and verify low or no oil pressure on the vehicle oil pressure gage or the oil indicator light. Listen for a noisy valve train or a knocking noise.
3. Inspect for the following: Engine oil diluted by moisture or unburned fuel mixtures Improper engine oil viscosity for the expected temperature Incorrect or faulty oil pressure gage sensor Incorrect or faulty oil pressure gage Plugged oil filter Malfunctioning oil filter bypass valve
4. Remove the oil pressure gage sensor or another engine block oil gallery plug.
5. Install an oil pressure gage.
6. Start the engine and then allow the engine to reach normal operation temperature.
7. Measure the engine oil pressure at the following RPM: Specification 7.1 42 kPa (6 psig, minimum, at 1,000 RPM 7.2 125 kPa (18 psig, minimum, at 2,000 RPM 7.3 166 kPa (24 psig, minimum, at 4,000 RPM
8. If the engine oil pressure is below minimum specifications, inspect the engine for one or more of the following: Oil pump worn or dirty Malfunctioning oil pump pressure relief valve Oil pump screen loose, plugged, or damaged Excessive bearing clearance Cracked, porous or restricted oil galleries Engine block oil gallery plugs missing or incorrectly installed Broken valve lifters

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Results Of Incorrect Operation

1. A plugged valve or hose may cause the following conditions: Rough idle Stalling or slow idle speed Oil leaks Oil in air cleaner Sludge in engine
2. A leaking crankcase ventilation valve or hose may cause the following conditions: Rough idle Stalling High idle speed

Functional Check

With these systems, any blow-by in excess of the system capacity, from a badly worn engine, sustained heavy load, etc., is exhausted into the air cleaner and is drawn into the engine.

Proper operation of the crankcase ventilation system depends upon a sealed engine. If oil slugging or dilution is noted and the crankcase ventilation system is functioning properly, check the engine for a possible cause. Correct any problems.

If an engine is idling rough, check for a clogged crankcase ventilation valve, a dirty vent filter, air cleaner element, or plugged hose. Replace as required. Use the following procedure

1. Remove the crankcase ventilation valve from the rocker arm cover.
2. Operate the engine at idle.
3. Place your thumb over the end of the valve in order to check for a vacuum. If there is no vacuum at the valve, check for the following items: Plugged hoses The manifold port The crankcase ventilation valve
4. Turn OFF the engine. Remove the crankcase ventilation valve. Shake the valve. Listen for the rattle of the check needle inside of the valve. If valve does not rattle, replace the valve.

Diagnostic Aids

The symptom may be intermittent due to moisture on the drive belt(s) or the pulleys. It may be necessary to spray a small amount of water on the drive belt(s) in order to duplicate the customers concern. If spraying water on the drive belt(s) 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 number(s) below refer to the step number(s) 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(s) 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 may 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.

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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 number(s) below refer to the step number(s) 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(s) 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(s) 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.

Scheme 370

The drive belt(s) 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 number(s) below refer to the step number(s) on the diagnostic table.

1. 3. This test is to verify that the noise is being caused by the drive belt(s) or 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(s) 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.

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

The drive belt(s) 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(s), completing the diagnostic table, and the noise is only heard when the drive belt(s) 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 number(s) below refer to the step number(s) 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(s) is causing the rumbling noise. Rumbling noise may be confused with an internal engine noise due to the similarity in the description. Remove only one drive belt at a time if the vehicle has multiple drive belts. When removing the drive 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(s) is to ensure that it is not causing a 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.

Scheme 372

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 number(s) below refer to the step number(s) 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(s) 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(s) may cause a vibration. While the drive belt(s) 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. This step should only be performed if the fan is driven by the drive belt. Inspect the engine cooling fan for bent, twisted, loose, or cracked blades. Inspect the fan clutch for smoothness, ease of turning. Inspect for a bent fan shaft or bent mounting flange.
6. 9. This step should only be performed if the water pump is driven by the drive belt. Inspect the water pump shaft for being bent. Also inspect the water pump bearings for smoothness and excessive play. Compare the water pump with a known good water pump.
7. 10. Accessory drive component brackets that are bent, cracked, or loose may put extra strain on that accessory component causing it to vibrate.

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

The number(s) below refer to the step number(s) 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 may 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.

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Excessive wear on a drive belt(s) 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(s) 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(s) fall off.

The number(s) below refer to the step number(s) on the diagnostic table.

1. 2. The inspection is to verify the drive belt(s) is correctly installed on all of the drive belt pulleys. Wear on the drive belt(s) may be caused by mis-positioning the drive belt(s) 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(s) 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(s) should not come in contact with an engine or a body component when snapping the throttle.

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Note. Allowing the drive belt tensioner to snap into the free position may result in damage to the tensioner.

Important: When the engine is operating the drive belt tensioner arm will move. Do not replace the drive belt tensioner because of movement in the drive belt tensioner arm.

1. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Position a 3/8 inch drive wrench on the drive belt tensioner arm and rotate the arm counterclockwise.
3. Move the drive belt tensioner through its full travel. The movement should feel smooth. There should be no binding. The tensioner should return freely.
4. If any binding is observed, replace the drive belt tensioner. Refer to «Drive Belt Tensioner Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
5. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

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1. Install a 3/8 inch drive wrench on the drive belt tensioner arm and rotate the arm counterclockwise.
2. Remove the drive belt.
3. Slowly release the tension on the drive belt tensioner arm.

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1. Route the drive belt over all the pulleys except the drive belt tensioner pulley.
2. Observe the drive belt routing for the vehicles without air conditioning.
3. Observe the drive belt routing for the vehicles with air conditioning.
4. Install a 3/8 inch drive wrench on the drive belt tensioner arm and rotate the arm counterclockwise.
5. Install the drive belt over the drive belt tensioner pulley.
6. Slowly release the tension on the drive belt tensioner arm.
7. Inspect for the drive belt being properly installed on the pulleys.
8. Avoid mis-positioning the drive belt by one or more grooves.
9. Confirm for the proper drive belt size and the correct drive belt routing by observing the location of the fix pointer and the index marks on the drive belt tensioner. With a new drive belt installed the fix pointer should align within the indentation on the drive belt tensioner.
10. With a used drive belt installed the fix pointer should not align past the index mark.

Scheme 385

1. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the bolt.
3. Remove the drive belt tensioner.

Scheme 386

1. Install the drive belt tensioner assembly.
2. Install the attaching bolt. Tighten Tighten the tensioner assembly bolt to 50 N.m (37 lb ft).
3. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

Scheme 387

1. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the drive belt idler pulley bolt.
3. Remove the drive belt idler pulley.

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1. Install the drive belt idler pulley and bolt to the generator mounting bracket. Tighten Tighten the bolt to 50 N.m (37 lb ft).
2. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

Scheme 389

1. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the belt idler pulley bolt.
3. Remove the belt idler pulley from the power steering pump mounting bracket.

Scheme 390

1. Install the belt idler pulley and the bolt to the power steering pump mounting bracket. Tighten Tighten the bolt to 50 N.m (37 lb ft).
2. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

Scheme 391

1. Raise the vehicle.
2. Inspect for loose or missing bolts at the following locations: The engine mount to the engine The engine mount to the engine mount frame bracket through-bolts The engine mount frame bracket to the frame
3. Replace missing or loose bolts. Refer to «Engine Mount Replacement - Left»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) or «Engine Mount Replacement - Right»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
4. In order to access the square tab on the right side of the engine remove the starter. Refer to appropriate STARTER article. Using a jack on the square tab at the rear of the engine block (left side shown the right side requires removal of the starter) raise the engine in order to complete the following tasks: Remove weight from the engine mount. Place a slight tension on the rubber cushion. Observe the engine mount while raising the engine.
5. Replace the engine mount if the following conditions exist: Heat check cracks cover the hard rubber surface. The rubber cushion is separated from the metal plate of the engine mount. There is a split through the rubber cushion. Replace the starter, if removed. Refer to appropriate STARTER article.
6. Lower the vehicle.

Removal Procedure

Note. Broken or deteriorated mounts can cause misalignment and destruction of certain drive train components. When a single mount breaks, the remaining mounts are subjected to abnormally high stresses.

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1. Raise the vehicle.
2. Remove the underbody shields, if equipped.
3. Remove the engine mount through-bolt and nut for the side being replaced.
4. Using a jack on the square tab (left side shown) at the rear of the engine block, raise the engine. In order to access the square tab on the right side remove the starter. Refer to appropriate STARTER article.
5. Raise the engine only enough to remove the engine mount.
6. Remove the bolts for the engine mount frame bracket.
7. Remove the engine mount frame bracket.
8. Remove the bolts holding the engine mount to the engine.
9. Remove the engine mount with the shield.

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1. Sub-assemble the engine mount, shield, and one bolt.
2. Install the engine mount and shield to the engine.
3. Install the engine mount to engine bolts. Tighten Tighten the engine mount to engine bolts to 55 N.m (33 lb ft).
4. Install the engine mount frame bracket to the frame.
5. Install the engine mount frame bracket bolts. Tighten Tighten the engine mount frame bracket bolts to 45 N.m (33 lb ft).
6. Lower the engine and remove the jack.
7. Install the engine mount through-bolts and nuts. Tighten Tighten the through-bolts or the nuts to the following: Tighten the through-bolts to 74 N.m (55 lb ft). Tighten the nuts to 63 N.m (46 lb ft).
8. Install the starter, if removed. Refer to appropriate STARTER article.
9. Lower the vehicle.

Note. Broken or deteriorated mounts can cause misalignment and destruction of certain drive train components. When a single mount breaks, the remaining mounts are subjected to abnormally high stresses.

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1. Raise the vehicle.
2. Remove the underbody shields, if equipped.
3. Remove the engine mount through-bolt and nut for the side being replaced.
4. Using a jack on the square tab (left side shown) at the rear of the engine block, raise the engine. In order to access the square tab on the right side remove the starter. Refer to appropriate STARTER article.
5. Raise the engine only enough to remove the engine mount.
6. Remove the bolts for the engine mount frame bracket.
7. Remove the engine mount frame bracket.
8. Remove the bolts holding the engine mount to the engine.
9. Remove the engine mount with the shield.

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1. Sub-assemble the engine mount, shield, and one bolt.
2. Install the engine mount and shield to the engine.
3. Install the engine mount to engine bolts. Tighten Tighten the engine mount to engine bolts to 55 N.m (41 lb ft).
4. Install the engine mount frame bracket to the frame.
5. Install the engine mount frame bracket bolts. Tighten Tighten the engine mount frame bracket bolts to 45 N.m (33 lb ft).
6. Lower the engine and remove the jack.
7. Install the engine mount through-bolts and nuts. Tighten Tighten the through-bolts or the nuts to the following: Tighten the through-bolts to 74 N.m (55 lb ft). Tighten the nuts to 63 N.m (46 lb ft).
8. Install the starter, if removed. Refer to appropriate STARTER article.
9. Lower the vehicle.

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Scheme 409

1. Disconnect the positive crankcase ventilation (PCV) valve hose assembly from the intake manifold.
2. Disconnect the PCV valve hose from the valve rocker arm cover.
3. Turn and remove the PCV valve cover from the upper intake manifold.
4. Remove and discard the seal (O-ring).

Scheme 410

Scheme 411

1. Install the PCV valve cover using the following procedure: 1.1. Install a NEW seal (O-ring) on the PCV valve cover. 1.2. Lubricate the seal with clean engine oil. 1.3. Install the PCV valve cover in the upper intake manifold. 1.4. Turn and lock the PCV valve cover in position.
2. Connect the PCV valve hose assembly to the valve rocker arm cover.
3. Connect the PCV valve hose assembly to the intake manifold.

Important : The upper intake does not have to be removed to remove the lower intake manifold.

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1. Disconnect the breather tube at the air cleaner outlet duct.
2. Remove the air cleaner outlet duct retaining wingnut.
3. Disconnect the IAT sensor harness connector.
4. Remove the air cleaner outlet duct from the throttle body.
5. Disconnect the accelerator cable from the throttle body.
6. Remove the accelerator cable from the accelerator control cable bracket.
7. Disconnect the cruise control cable, if equipped from the throttle shaft and the accelerator cable bracket.
8. Disconnect the vacuum hose from the intake manifold for the vacuum tank.
9. Remove the power brake booster vacuum hose.
10. Disconnect the following electrical connectors: The A/C compressor clutch (1) The A/C compressor cutoff switch (5), if equipped The throttle position (TP) sensor (2) The idle air control (IAC) motor (3)
11. Disconnect the following electrical connectors: The fuel meter body assembly (1) The manifold absolute pressure (MAP) sensor (3) The EVAP canister purge solenoid valve (2)
12. Remove the engine wire harness clip from the accelerator cable bracket.
13. Move the engine wiring harness aside.
14. Remove the accelerator cable bracket from the throttle body and the intake manifold.
15. Remove the accelerator and cruise control cable bracket from the throttle body. Leave the accelerator and cruise control cables on the bracket.
16. Remove the PCV valve hose assembly from the intake manifold and the valve rocker arm cover.
17. Remove the bracket for the engine wiring harness from the intake manifold stud.
18. Remove the fuel lines from the fuel meter body assembly.
19. Remove the EVAP canister purge solenoid valve.
20. Remove the studs for the upper intake manifold.
21. Remove the upper intake manifold.
22. Remove the upper intake manifold gasket from the groove.
23. Discard the gasket.
24. Remove the seal from the fuel meter body assembly.
25. Discard the seal. Important : Do not immerse the assembled upper intake manifold in cleaning solvent.
26. Clean all sealing surfaces and the inside of the upper intake manifold with a shop towel and cleaning solvent.
27. Inspect the upper intake manifold for the following: Cracks or other damage to the exterior Cracking or damage to the gasket grooves Loose or damaged bolt hole thread inserts Damage to the throttle body mounting surface
28. If replacing the upper intake manifold, turn and remove the power brake booster vacuum tube fitting from the upper intake manifold.
29. Remove and discard the seal.
30. If replacing the upper intake manifold, turn and remove the PCV valve cover from the upper intake manifold.
31. Remove and discard the seal.
32. Remove the throttle body if replacing the upper intake manifold. Refer to appropriate REMOVAL, OVERHAUL & REPLACEMENT article.
33. Remove the MAP sensor if replacing the upper intake manifold. Refer to appropriate REMOVAL, OVERHAUL & REPLACEMENT article.

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1. Install the throttle body, if removed. Refer to appropriate REMOVAL, OVERHAUL & REPLACEMENT article.
2. Install the MAP sensor, if removed. Refer to appropriate REMOVAL, OVERHAUL & REPLACEMENT article.
3. Install the PCV valve cover, if removed, using the following procedure: 3.1. Install a NEW seal (O-ring) on the PCV valve cover. 3.2. Lubricate the seal with clean engine oil. 3.3. Install the PCV valve cover in the upper intake manifold. 3.4. Turn and lock the PCV valve cover in position.
4. Install the power brake booster vacuum tube fitting, if removed, using the following procedure: 4.1 Install a NEW seal (O-ring) on the power brake booster vacuum tube fitting. 4.2 Lubricate the seal with clean engine oil. 4.3 Install the power brake booster vacuum tube fitting in the upper intake manifold. 4.4 Turn and lock the power brake booster vacuum tube fitting in position.
5. Install a NEW seal on the fuel meter body assembly.
6. Lubricate the seal with clean engine oil.
7. Install a NEW upper intake manifold to lower intake manifold gasket in the groove of the upper intake manifold.
8. Install the upper intake manifold onto the lower intake manifold.
9. If reusing the fasteners, apply threadlock GM P/N 12345382 or equivalent to the threads of the upper intake manifold attaching bolts.
10. Install the upper intake manifold attaching studs. Tighten 10.1 Tighten the upper intake manifold attaching studs on the first pass to 5 N.m (44 lb in). 10.2 Tighten the upper intake manifold attaching studs on the final pass to 9 N.m (80 lb in).
11. Install the fuel lines to the fuel meter body assembly.
12. Install the EVAP canister purge solenoid valve. Refer to appropriate REMOVAL, OVERHAUL & REPLACEMENT article.
13. Install the bracket for the engine wiring harness on the lower intake manifold stud.
14. Install the engine wiring harness bracket nut. Tighten Tighten the engine wiring harness bracket nut to 12 N.m (106 lb in).
15. Install the accelerator and cruise control cable bracket to the throttle body.
16. Install the accelerator and cruise control cable bracket nuts. Tighten Tighten the accelerator and cruise control cable bracket nuts to 9 N.m (80 lb in).
17. Install the accelerator control cable bracket to the throttle body and the intake manifold. Tighten Tighten the accelerator control cable bracket studs and nuts to 12 N.m (106 lb in).
18. Connect the PCV valve hose assembly to the intake manifold and the valve rocker arm cover.
19. Position the engine wiring harness.
20. Install the wire harness clip to the accelerator cable bracket.
21. Connect the following electrical connectors: The fuel meter body assembly (1) The manifold absolute pressure (MAP) sensor (3) The EVAP canister purge solenoid valve (2)
22. Connect the following electrical connectors: The A/C compressor clutch (1) The A/C compressor cutoff switch (5), if equipped The throttle position (TP) sensor (2) The idle air control (IAC) motor (3)
23. Connect the vacuum hose from the vacuum tank to the intake manifold.
24. Install the power brake booster vacuum hose to the intake manifold.
25. Install the cruise control cable, if equipped to the throttle shaft and the bracket.
26. Install the accelerator cable onto the throttle body.
27. Wrap the cable in between the finger of the hook tab and the pulley wall. Make sure that the cable is fully seated in the pulley groove. The cable must not lie outside of the hook tab.
28. Install the accelerator cable to the accelerator cable control bracket. NOTE: Handle the MAF sensor carefully. Do not drop the MAF sensor in order to prevent damage to the MAF sensor. Do not damage the screen located on the air inlet end of the MAF. Do not touch the sensing elements. Do not allow solvents and lubricants to come in contact with the sensing elements. Use a small amount of a soap based solution in order to aid in the installation.
29. Install air cleaner outlet duct to throttle body.
30. Install air cleaner outlet duct to MAF sensor. Tighten Tighten the hose clamp to 4 N.m (32 lb in).
31. Connect the IAT sensor harness connector.
32. Install the air cleaner outlet duct retaining wingnut. Tighten Tighten the wingnut to 2 N.m (18 lb in).
33. Connect the breather tube to the air cleaner outlet duct.

Important : You do not have to remove the upper intake manifold in order to remove the lower intake manifold.

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1. Disconnect the negative battery cable.
2. Disconnect the breather tube at the air cleaner outlet duct.
3. Remove the air cleaner outlet duct retaining wingnut.
4. Disconnect the IAT sensor harness connector.
5. Remove the air cleaner outlet duct from the throttle body.
6. Disconnect the accelerator cable from the throttle body.
7. Remove the accelerator cable from the accelerator control cable bracket.
8. Disconnect the cruise control cable, if equipped, from the throttle shaft and the accelerator cable bracket.
9. Disconnect the vacuum hose from the intake manifold, if equipped with A/C.
10. Disconnect the power brake booster vacuum hose
11. Drain the cooling system.
12. Remove the radiator inlet hose at the water outlet.
13. Remove the heater hose from the intake manifold.
14. Remove the water pump inlet hose from the intake manifold.
15. Disconnect the following electrical connectors: The fuel meter body assembly (1) The EVAP canister purge solenoid valve (2) The manifold air pressure (MAP) sensor (3)
16. Disconnect the following electrical connectors: The exhaust gas recirculation (EGR) valve (3) The ignition coil (2) The ignition control module (ICM) (1) The generator (4)
17. Disconnect the following electrical connectors: The idle air control (IAC) motor (3) The throttle position (TP) sensor (2) The A/C compressor cutoff switch, if equipped (5) The A/C clutch switch, if equipped (1) The engine coolant temperature (ECT) sensor (4)
18. Remove the engine wiring harness clips from the brackets.
19. Move the engine wiring harness aside.
20. Remove the accelerator cable bracket from the throttle body and the intake manifold.
21. Remove the accelerator and the cruise control cable bracket from the throttle bracket. Leave the accelerator and cruise control cables on the bracket.
22. Disconnect the PCV hose assembly from the intake manifold and the valve rocker arm cover.
23. Remove the EVAP canister purge solenoid valve. Refer to appropriate REMOVAL, OVERHAUL & REPLACEMENT article.
24. Remove the spark plug wire harness retainer from the exhaust gas recirculation (EGR) valve inlet pipe.
25. Remove the clamp bolt for the EGR valve inlet pipe.
26. Remove the EGR valve inlet pipe from the intake and the exhaust manifolds.
27. Remove the distributor.
28. Disconnect the fuel supply and return pipes at the rear of the intake manifold. Important: Do not discharge the refrigerant.
29. Perform the following in order to remove the left front bolt for the intake manifold: 29.1. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) . 29.2. Loosen the nut for the power steering pump rear bracket at the side of the engine. 29.3. Remove the secondary air injection (AIR) reactor pipe bracket nut from the power steering pump rear bracket front stud, if equipped. 29.4. Remove the nut for the power steering pump rear bracket at the front of the engine. 29.5. Remove the bolts and the nut for the power steering pump mounting bracket. 29.6. Leave the A/C compressor, if equipped, and the power steering pump on the power steering pump mounting bracket. 29.7. Slide the power steering pump bracket forward to access the bolt at the front of the intake manifold.
30. Remove the engine coolant temperature (ECT) sensor wire connector (if equipped) from the engine wiring harness bracket.
31. Remove the lower intake manifold bolts. Important: The intake manifold may be removed as an assembly. Do not remove the specific intake manifold components unless component service is required. Do not allow dirt or debris to enter the fuel system. Ensure that the ends of the fuel system are properly sealed. Do not disassemble the Central Sequential Fuel Injection (SFI) unit, unless service is required.
32. Remove the intake manifold assembly.
33. Remove and discard the lower intake manifold gaskets. Important: Do not immerse the assembled intake manifold in cleaning solvent.
34. Clean the lower intake manifold in cleaning solvent.
35. Dry the lower intake manifold with compressed air.
36. Inspect the lower intake manifold for the following: Damage to the gasket sealing surfaces (1), (2) and (3) Restricted exhaust gas recirculation (EGR) system passages (4) Restricted cooling system passages (5) Cracks or damage Damage to the threaded bolt holes

Scheme 467

Installation Procedure

Note. Apply the proper amount of the sealant when assembling this component. Excessive use of the sealant can prohibit the component from sealing properly. A component that is not sealed properly can leak leading to extensive engine damage.

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1. Apply a 4.0 mm (0.157 in) patch of adhesive GM P/N 12346141 or equivalent to the cylinder head side of the lower intake manifold gasket at each end. Important: The lower intake manifold gasket must be installed while the adhesive is still wet to the touch.
2. Install the lower intake manifold gasket onto the cylinder head. Use the gasket locator pins in order to properly seat the lower intake manifold gasket on the cylinder head. NOTE: Apply the proper amount of the sealant when assembling this component. Excessive use of the sealant can prohibit the component from sealing properly. A component that is not sealed properly can leak leading to extensive engine damage. Important: The lower intake manifold must be installed and the fasteners tightened while the adhesive is still wet to the touch.
3. Apply a 5 mm (0.197 in) bead of adhesive GM P/N 12346141 or equivalent to the front top of the engine block.
4. Extend the adhesive bead 13 mm (0.50 in) onto each lower intake manifold gasket.
5. Apply a 5 mm (0.197 in) bead of adhesive GM P/N 12346141 or equivalent to the rear top of the engine block.
6. Extend the adhesive bead 13 mm (0.50 in) onto each lower intake manifold gasket.
7. Install the lower intake manifold onto the engine block.
8. If reusing the fasteners, apply threadlock GM P/N 12345382 or equivalent to the threads of the lower intake manifold bolts.
9. Install the lower intake manifold bolts. NOTE: Proper lower intake manifold fastener tightening sequence and torque is critical. Always follow the tightening sequence, and torque the intake manifold bolts using the 3 step method Failing to do so may distort the crankshaft bearing bore alignment and cause damage to the crankshaft bearings.
10. Tighten the lower intake manifold bolts. Tighten 10.1 Tighten the bolts on the first pass in sequence to 3 N.m (27 lb in). 10.2 Tighten the bolts on the second pass in sequence to 12 N.m (106 lb in). 10.3 Tighten the bolts on the final pass in sequence to 15 N.m (11 lb ft).
11. Position the power steering pump mounting bracket.
12. Loosely install the power steering pump mounting bracket bolts and nuts.
13. Install the nut for the power steering pump rear bracket at the front of the engine. Tighten Tighten the power steering pump mounting bracket bolts and the power steering pump rear bracket nuts to 41 N.m (30 lb ft).
14. Install the AIR reactor pipe bracket nut to the power steering pump rear bracket front stud, if equipped. Tighten Tighten the AIR reactor pipe bracket nut to 41 N.m (30 lb ft).
15. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
16. Install the fuel supply and return pipes to the rear of the intake manifold. Important: In order to install the distributor for the correct engine timing, position the engine to number one cylinder top dead center.
17. Remove the spark plug for number one cylinder.
18. Rotate the crankshaft until number one cylinder is in the compression stroke.
19. Align the 2 reference marks on the crankshaft balancer (1) and (4) with the 2 alignment marks (2) and (3) on the front cover.
20. Install the spark plug.
21. Install the distributor.
22. Install the EVAP canister purge solenoid valve.
23. Install the EGR valve inlet pipe to the intake manifold and the exhaust manifold. Tighten 23.1 Tighten the EGR valve inlet pipe intake manifold nut to 25 N.m (18 lb ft). 23.2 Tighten the EGR valve inlet pipe exhaust manifold nut to 30 N.m (22 lb ft). 23.3 Tighten the EGR valve inlet pipe clamp bolt 25 N.m (18 lb ft).
24. Install the spark plug wire harness retainer on the EGR valve inlet pipe.
25. Install the PCV hose assembly to the intake manifold and the valve rocker arm cover.
26. Install the accelerator cable and cruise control cable bracket to the throttle body. Tighten Tighten the accelerator cable and cruise control bracket nuts to 9 N.m (80 lb in).
27. Install the accelerator cable bracket to the intake manifold and the throttle body. Tighten Tighten the accelerator cable bracket studs and nuts to 12 N.m (106 lb in).
28. Position the engine wiring harness.
29. Install the engine wiring harness clips in the brackets.
30. Connect the following electrical connectors: The idle air control (IAC) motor (3) The throttle position (TP) sensor (2) The A/C compressor cutoff switch, if equipped (5) The A/C clutch switch, if equipped (1) The engine coolant temperature (ECT) sensor (4)
31. Connect the following electrical connectors: The fuel meter body assembly (1) The EVAP canister purge solenoid valve (2) The manifold air pressure (MAP) sensor (3)
32. Connect the following electrical connectors: The exhaust gas recirculation (EGR) valve (3) The ignition coil (2) The ignition control module (ICM) (1) The generator (4)
33. Connect the power brake booster vacuum hose.
34. Connect the vacuum hose to the intake manifold, if equipped with A/C.
35. Install the water pump inlet hose to the intake manifold.
36. Install the heater hose to the intake manifold.
37. Install the radiator inlet hose to the thermostat housing.
38. Install the cruise control cable, if equipped to the bracket and the throttle shaft.
39. Install the accelerator cable onto the throttle body.
40. Wrap the cable in between the finger of the hook tab and the pulley wall. Make sure that the cable is fully seated in the pulley groove. The cable must not lie outside of the hook tab.
41. Install the accelerator cable to the accelerator cable control bracket. NOTE: Handle the MAF sensor carefully. Do not drop the MAF sensor in order to prevent damage to the MAF sensor. Do not damage the screen located on the air inlet end of the MAF. Do not touch the sensing elements. Do not allow solvents and lubricants to come in contact with the sensing elements. Use a small amount of a soap based solution in order to aid in the installation
42. Install air cleaner outlet duct to throttle body.
43. Install air cleaner outlet duct to MAF sensor. Tighten Tighten the hose clamp to 4 N.m (32 lb in).
44. Connect the IAT sensor harness connector.
45. Install the air cleaner outlet duct retaining wingnut. Tighten Tighten the wingnut to 2 N.m (18 lb in).
46. Connect the breather tube to the air cleaner outlet duct.
47. Fill the cooling system.
48. Connect the battery negative cable.

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1. Disconnect the breather tube at the air cleaner outlet duct.
2. Remove the air cleaner outlet duct retaining wingnut.
3. Disconnect the IAT sensor harness connector.
4. Remove the air cleaner outlet duct from the throttle body.
5. Partially drain the cooling system.
6. Remove the radiator inlet hose from the water outlet housing.
7. Remove the PCV valve hose assembly from the valve rocker arm cover.
8. Disconnect the engine coolant temperature (ECT) sensor electrical connector.
9. Remove the spark plug wire harness retainer from the exhaust gas recirculation (EGR) valve inlet pipe.
10. Remove the clamp bolt for the EGR valve inlet pipe.
11. Remove the EGR valve inlet pipe from the intake and the exhaust manifolds. Important: A/C compressor and bracket removal is not necessary.
12. Remove the valve rocker arm cover bolts.
13. Remove the valve rocker arm cover bolt grommets.
14. Discard the valve rocker arm cover bolt grommets.
15. Remove the valve rocker arm cover.
16. Remove the valve rocker arm cover gasket.
17. Discard the valve rocker arm cover gasket.
18. Clean the valve rocker arm cover in cleaning solvent.
19. Dry the valve rocker arm cover with compressed air.
20. Inspect the valve rocker arm cover for the following: Damage to the PCV valve grommet (1) Damage to the bolt holes (2) A damaged valve rocker arm cover may interfere with the valve rocker arms. Damage to the exterior of the valve rocker arm cover (3) Gouges or damage to the sealing surface (4) Damage to the oil fill tube grommet (5) Restrictions to the ventilation system passages

Important: Do not reuse the valve cover gasket or the valve rocker arm cover bolt grommets.

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1. Install the NEW valve rocker arm cover gasket into the groove of the valve rocker arm cover.
2. Install the NEW valve rocker arm cover bolt grommets into the valve rocker arm cover.
3. Install the valve rocker arm cover onto the cylinder head.
4. Install the valve rocker arm cover bolts. Tighten Tighten the valve rocker arm cover bolts to 12 N.m (106 lb in).
5. Install the EGR valve inlet pipe to the intake manifold and the exhaust manifold. Tighten 5.1. Tighten the EGR valve inlet pipe intake manifold nut to 25 N.m (18 lb ft). 5.2. Tighten the EGR valve inlet pipe exhaust manifold nut to 30 N.m (22 lb ft). 5.3. Tighten the EGR valve inlet pipe clamp bolt 25 N.m (18 lb ft).
6. Install the spark plug wire harness retainer on the EGR valve inlet pipe.
7. Install the radiator inlet hose to the water outlet housing.
8. Fill the cooling system.
9. Install the PCV valve hose assembly to the valve rocker arm cover.
10. Connect the ECT sensor electrical connector. NOTE: Handle the MAF sensor carefully. Do not drop the MAF sensor in order to prevent damage to the MAF sensor. Do not damage the screen located on the air inlet end of the MAF. Do not touch the sensing elements. Do not allow solvents and lubricants to come in contact with the sensing elements. Use a small amount of a soap based solution in order to aid in the installation.
11. Install air cleaner outlet duct to throttle body.
12. Install air cleaner outlet duct to MAF sensor. Tighten Tighten the hose clamp to 4 N.m (32 lb in).
13. Connect the IAT sensor harness connector.
14. Install the air cleaner outlet duct retaining wingnut. Tighten Tighten the wingnut to 2 N.m (18 lb in).
15. Connect the breather tube to the air cleaner outlet duct.

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1. Remove the PCV tube from the air cleaner outlet duct and the valve rocker arm cover.
2. Disconnect the spark plug wires from the spark plugs for the right side of the engine.
3. Remove the EVAP canister purge solenoid valve.
4. Unfasten the heater hose retainer above the valve rocker arm cover.
5. Move and secure the heater hoses aside.
6. Remove the bolt (3) holding the engine wiring harness bracket to the generator.
7. Disconnect the crankcase position (CKP) sensor electrical connector (2).
8. Move and secure the engine wiring harness aside.
9. Remove the valve rocker arm cover bolts.
10. Remove the valve rocker arm cover bolt grommets.
11. Discard the valve rocker arm cover bolt grommets.
12. Remove the valve rocker arm cover.
13. Remove the valve rocker arm cover gasket.
14. Discard the valve rocker arm cover gasket.
15. Clean the valve rocker arm cover in cleaning solvent.
16. Dry the valve rocker arm cover with compressed air.
17. Inspect the valve rocker arm cover for the following: Damage to the PCV valve grommet (1) Damage to the bolt holes (2) A damaged valve rocker arm cover may interfere with the valve rocker arms. Damage to the exterior of the valve rocker arm cover (3) Gouges or damage to the sealing surface (4) Damage to the oil fill tube grommet (5) Restrictions to the ventilation system passages

Important: Do not reuse the valve cover gasket or the valve rocker arm cover bolt grommets.

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Scheme 521

1. Install the NEW valve rocker arm cover gasket into the groove of the valve rocker arm cover.
2. Install the NEW valve rocker arm cover bolt grommets into the valve rocker arm cover.
3. Install the valve rocker arm cover onto the cylinder head.
4. Install the valve rocker arm cover bolts. Tighten Tighten the valve rocker arm cover bolts to 12 N.m (106 lb in).
5. Position the engine wiring harness.
6. Connect the CKP sensor electrical connector (2).
7. Install the engine wiring harness and the bolt (3) to the generator mounting bracket. Tighten Tighten the engine wiring harness bolt to 25 N.m (18 lb ft).
8. Position the heater hoses.
9. Install the heater hoses in the retainer above the valve rocker arm cover.
10. Install the EVAP canister purge solenoid valve.
11. Connect the spark plug wires to the spark plugs for the right side of the engine.
12. Install the PCV tube to the air cleaner outlet duct and the valve rocker arm cover.

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1. Remove the valve rocker arm cover. Refer to the appropriate procedure: «Valve Rocker Arm Cover Replacement - Left»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) «Valve Rocker Arm Cover Replacement - Right»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) Important: Mark, sort, and organize all the components for assembly.
2. Remove the valve rocker arms.
3. Remove the valve rocker arm supports.
4. Remove the valve pushrods. Important: Parts that are to be reused must be marked, sorted, and organized for assembly.
5. Mark, sort, and organize the components for assembly.
6. Clean the components with cleaning solvent.
7. Dry the components with compressed air.
8. Inspect the valve rocker arm components for the following: Valve rocker arm valve pushrod socket contact surface (1) The contact surface must be smooth with no scoring or excessive wear. Valve rocker arm roller pivot for binding or damage (2) Valve rocker arm valve stem contact surface (3) The contact surface should be smooth with no scoring or excessive wear. Valve rocker arm bolt threads for damage (4)
9. Inspect the valve pushrods for the following: Restriction of the oil passage (1) Wear or scoring of the end contact surfaces (2) The end contact surfaces must be smooth with no scoring or excessive wear. Shaft for bends (3) Roll the valve pushrod on a flat surface to determine if the valve pushrod is bent.
10. Inspect the valve rocker support for excessive wear or damage.

Important: Be sure to keep parts in order. Parts must be reinstalled into the original location and position

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1. Install the valve pushrods. Important: Be sure that the arrow on the valve rocker arm support is in the up position
2. Install the valve rocker arm supports.
3. Apply prelube GM P/N 12345501 or equivalent to the following valve rocker arm contact surfaces: Valve pushrod socket (1) Roller pivot (2) Valve stem tip (3)
4. Install the valve rocker arm assemblies as follows: 4.1. Finger start the bolt at location (1). 4.2. Finger start the bolt at location (2). 4.3. Finger start the bolt at location (3). 4.4. Finger start the remaining valve rocker arm bolts.
5. Rotate the crankshaft balancer to position the crankshaft balancer alignment mark (1) 57-63 degrees clockwise or counterclockwise from the engine front cover alignment tab (2). Important: Once the valve rocker arm assemblies are installed and properly torqued, no additional valve lash adjustment is required.
6. Tighten the valve rocker arm bolts. Tighten Tighten valve rocker arm bolts to 30 N.m (22 lb ft).
7. Install the valve rocker arm cover. Refer to the appropriate procedure: «Valve Rocker Arm Cover Replacement - Left»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) «Valve Rocker Arm Cover Replacement - Right»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l)

Tools Required

1. J 22794 Spark Plug Port Adapter
2. J 38606 Valve Spring Compressor
3. J 5892-D Valve Spring Compressor
4. J 42073 Valve Stem Seal Installer

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1. Remove the valve rocker arm cover. Refer to «Valve Rocker Arm Cover Replacement - Left»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) . Refer to «Valve Rocker Arm Cover Replacement - Right»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the required valve rocker arms. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
3. Remove the required spark plugs.
4. Install the J 22794 into the spark plug hole.
5. Connect a shop air supply hose and apply compressed air in order to hold the valves in place.
6. Remove a bolt from a valve rocker arm.
7. Install a flat washer on the bolt.
8. Install the bolt in the valve rocker arm bolt hole for the valve spring requiring removal. CAUTION: Compressed valve springs have high tension against the valve spring compressor. Valve springs that are not properly compressed by or released from the valve spring compressor can be ejected from the valve spring compressor with intense force. Use care when compressing or releasing the valve spring with the valve spring compressor and when removing or installing the valve stem keys. Failing to use care may cause personal injury.
9. Use the J 5892-D in order to compress the valve spring. 9.1. Hook the slotted end of J 5892-D under the washer on the valve rocker arm bolt. 9.2. Apply steady pressure on the valve spring cap until the valve keys are accessible. NOTE: Completely engage the J 38606 jaws on the valve spring. The J 38606 may slip off and scratch the valve spring. Replace the valve spring if the valve spring becomes scratch.
10. Use J 38606 when J 5892-D will not fit.
11. Remove the valve keys (1).
12. Carefully release the valve spring tension
13. Remove the J 5892-D or the J 38606.
14. Remove the valve spring cap (2) and valve spring (3).
15. Remove the valve stem oil seal (4).

Important: The exhaust valve oil stem seal has the letters EX (1) molded into the top of the seal. The exhaust valve oil stem seal material is brown in color (2) with a white stripe (3) painted onto the outside diameter of the seal, or the material may be red in color (2) with no paint stripe. The intake valve oil seal is black in color.

Scheme 537

Scheme 538

Scheme 539

Scheme 540

Scheme 541

Scheme 542

1. Assemble the valve into the proper valve guide.
2. Select the proper valve stem oil seal for the specific valve guide.
3. Lubricate the valve stem oil seal and the outside diameter of the valve guide with clean engine oil.
4. Assemble the valve stem oil seal onto the valve stem.
5. Using the J 42073, install the valve stem oil seal onto the valve guide. 5.1. Tap the valve stem oil seal onto the valve guide until the J 42073 bottoms against the valve spring seat. 5.2. Inspect the valve stem oil seal. The valve stem oil seal should not be bottomed against the valve guide. There should be a 1-2 mm (0.03937-0.07874 in) gap between the bottom edge of the valve stem oil seal and the valve guide.
6. Install the valve spring (3).
7. Install the valve spring cap (2) onto the valve spring (3), over the valve stem. CAUTION: Compressed valve springs have high tension against the valve spring compressor. Valve springs that are not properly compressed by or released from the valve spring compressor can be ejected from the valve spring compressor with intense force. Use care when compressing or releasing the valve spring with the valve spring compressor and when removing or installing the valve stem keys. Failing to use care may cause personal injury.
8. Use the J 5892-D in order to compress the valve spring. Hook the slotted end of J 5892-D under the washer on the valve rocker arm bolt.
9. Apply steady pressure on the valve spring cap until the valve keys are accessible. NOTE: Completely engage the J 38606 jaws on the valve spring. The J 38606 may slip off and scratch the valve spring. Replace the valve spring if the valve spring becomes scratch.
10. Use the J 38606 if the clearance does not permit use of the J 5892-D .
11. Install the valve stem O-ring seal.
12. Install the valve stem keys. Use grease in order to hold the valve stem keys in place.
13. Carefully release the valve spring pressure, making sure the valve stem keys stay in place. NOTE: The valve stem keys must correctly seat in the valve spring cap. Engine damage may occur by not installing properly.
14. Remove the J 5892-D or the J 38606. 14.1. Look to ensure that the valve stem keys seat properly in the upper groove of the valve stem. 14.2. Tap the end of the valve stem with a plastic faced hammer in order to seat the valve stem keys, if necessary.
15. Remove the J 22794.
16. Install the spark plugs.
17. Install the valve rocker arms to the cylinder head. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
18. Install the valve rocker arm cover. Refer to «Valve Rocker Arm Cover Replacement - Left»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) . Refer to «Valve Rocker Arm Cover Replacement - Right»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

J 3049-A Valve Lifter Remover

Scheme 543

Scheme 544

Scheme 545

Scheme 546

Scheme 547

Scheme 548

1. Remove the lower intake manifold. Refer to «Intake Manifold Replacement - Lower»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the valve rocker arms and the valve pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) . Important: Place the components in a rack so that the components can be reinstalled to their original location
3. Remove the bolts and valve lifter pushrod guide. Important: Place the valve lifters in the rack in the upright position in order to maintain the oil inside the valve lifters.
4. Remove the valve lifters. Important: Some valve lifters may be stuck in the valve lifter bores because of gum or varnish deposits and may require the use of J3049-A for removal.
5. Use the J 3049-A in order to remove the stuck valve lifters.
6. Use a cleaning solvent and a shop towel to clean any varnish from the valve lifter bores.
7. Inspect the valve lifter bores for excessive wear or scoring. Replace the engine block if there is excessive wear or deep scoring.
8. Inspect the camshaft for wear or damage. If the wear is questionable remove the camshaft and inspect. Refer to «CAMSHAFT & BEARINGS CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__camshaft-bearings-cleaning-inspection) . Important: Components that are to be reused must be marked, sorted, and organized for assembly.
9. Mark, sort, and organize the components for assembly.
10. Clean the components in cleaning solvent.
11. Dry the components with compressed air.
12. Inspect the valve lifter pushrod guides for excessive wear.
13. Inspect the valve lifter pushrod guides for cracks or damage.
14. Inspect the valve lifter for the following: Broken or damaged clip (1) Worn pushrod socket (2) Scuffed or worn lifter body (3) If the valve lifter shows scuffing or wear, inspect the engine block valve lifter bores for wear. Worn roller (4) Loose or damaged pin (5) Plugged oil hole (6)

Important: It is normal for NEW lifters to make a slight ticking noise when the engine is first started. Increasing the engine RPMs slightly to raise oil pressure should stop the noise.

Scheme 549

Scheme 550

1. Apply lubricant GM P/N 12345501 or equivalent to the valve lifter rollers. Important: If reusing the valve lifters, install the valve lifters in the original positions.
2. Install the valve lifters.
3. Install the valve lifter pushrod guides. Tighten Tighten the valve lifter pushrod guide bolts to 16 N.m (12 lb ft).
4. Install the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
5. Install the lower intake manifold. Refer to «Intake Manifold Replacement - Lower»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

J 36660-A Electronic Torque Angle Meter

Scheme 551

Scheme 552

Scheme 553

Scheme 554

Scheme 555

Scheme 556

Scheme 557

Scheme 558

Scheme 559

1. Disconnect the negative battery cable.
2. Drain the cooling.
3. Remove the engine cooling fan assembly.
4. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
5. Loosen the nut holding the power steering pump rear bracket to the side of the engine.
6. Remove the nut holding the power steering pump rear bracket to the front of the engine
7. Remove the three bolts and the nut holding the power steering pump mounting bracket to the engine.
8. With the power steering pump and the A/C compressor still attached, slide the power steering pump mount bracket off of the stud and set aside.
9. Remove the power steering pump mounting bracket stud from the cylinder head.
10. Remove the lower intake manifold. Refer to «Intake Manifold Replacement - Lower»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
11. Remove the exhaust manifold. Refer to «EXHAUST MANIFOLD REMOVAL - LEFT»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__exhaust-manifold-removal-left) .
12. Remove the spark plug wire harness and the spark plug wire support.
13. Remove the valve pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
14. Remove the ground wire bolt and the ground wire from the rear of the cylinder head.
15. Secure the ground wire out of the way.
16. Remove the bolt holding the fuel pipe bracket to the rear of the cylinder head.
17. Remove the engine coolant temperature sensor (if applicable).
18. Remove the engine coolant temperature gage sensor (if applicable).
19. Remove the spark plugs.
20. Remove the cylinder head bolts. NOTE: After removal, place the cylinder head on two wood blocks to prevent damage.
21. Remove the cylinder head.
22. Remove and discard the cylinder head gasket.
23. Remove the dowel pins (cylinder head locator) (if required).
24. Clean the engine block and the cylinder head sealing surfaces. NOTE: Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.
25. Clean the cylinder head bolts and the engine block bolt holes.
26. For further service to the cylinder head refer to the following: Refer to «CYLINDER HEAD DISASSEMBLE»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__cylinder-head-disassemble) . Refer to «CYLINDER HEAD CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__cylinder-head-cleaning-inspection) . Refer to «VALVE GUIDE REAMING/VALVE & SEAT GRINDING»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__valve-guide-reamingvalve-seat-grinding) . Refer to «CYLINDER HEAD ASSEMBLE»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__cylinder-head-assemble) .

Scheme 560

Scheme 561

Scheme 562

Scheme 563

Scheme 564

Scheme 565

Scheme 566

Scheme 567

Scheme 568

Scheme 569

Scheme 570

1. Clean the cylinder head gasket surfaces on the engine block.
2. Inspect the dowel pins (cylinder head locator) for proper installation
3. Clean the cylinder head gasket surfaces on the cylinder head. Important: Do not use any type sealer on the cylinder head gasket (unless specified).
4. Install the NEW cylinder head gasket in position over the dowel pins (cylinder head locator).
5. Install the cylinder head onto the engine block. Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.
6. Apply sealant GM P/N 12346004 or equivalent to the threads of the cylinder head bolts.
7. Install the cylinder head bolts finger tight.
8. Tighten the cylinder head bolts in sequence on the first pass. Tighten Tighten the bolts in sequence on the first pass to 30 N.m (22 lb ft).
9. Use the J 36660-A in order to tighten the cylinder head bolts in sequence. Tighten Rotate the long bolts (1, 4, 5, 8, and 9) an additional 75 degrees. Rotate the medium bolts (12 and 13) an additional 65 degrees. Rotate the short bolts (2, 3, 6, 7, 10, and 11) an additional 55 degrees.
10. Install the spark plugs.
11. If reusing the engine coolant temperature gauge sensor (if applicable), apply sealant GM P/N 12346004 or equivalent to the threads of the engine coolant temperature gauge sensor.
12. Install the engine coolant temperature gauge sensor (if applicable). Tighten Tighten the engine coolant temperature gauge sensor to 20 N.m (15 lb ft).
13. If reusing the engine coolant temperature sensor (if applicable), apply sealant GM P/N 12346004 or equivalent to the threads of the engine coolant temperature gauge sensor.
14. Install the engine coolant temperature sensor (if applicable). Tighten Tighten the engine coolant temperature sensor to 20 N.m (15 lb ft).
15. Install the valve pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
16. Install the lower intake manifold. Refer to «Intake Manifold Replacement - Lower»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
17. Install the exhaust manifold. Refer to «EXHAUST MANIFOLD INSTALLATION - LEFT»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) .
18. Install the spark plug wire harness and spark plug wire support. Tighten Tighten the support bolts to 12 N.m (106 lb in).
19. Install the bolt for and the fuel pipe bracket to the rear of the cylinder head. Tighten Tighten the fuel pipe bracket bolt to 30 N.m (22 lb ft).
20. Install the ground wire and the ground wire bolt to the rear of the cylinder head. Tighten Tighten the ground wire bolt to 35 N.m (26 lb ft).
21. Install the stud for the power steering pump mounting bracket to the cylinder head. Tighten Tighten the power steering pump mounting bracket stud to 20 N.m (15 lb ft).
22. Slide the power steering pump mounting bracket with the power steering pump and the A/C compressor on the stud.
23. Position the power steering pump rear bracket on the studs.
24. Install the power steering pump mounting bracket three bolts and the nut.
25. Install the nut for the power steering pump rear bracket to the front of the engine. Tighten Tighten the power steering pump mounting bracket and the power steering pump rear bracket bolts and the nuts to 41 N.m (30 lb ft).
26. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
27. Install the engine cooling fan assembly.
28. Fill the cooling system.
29. Connect the negative battery cable.

J 36660-A Electronic Torque Angle Meter

Scheme 571

Scheme 572

Scheme 573

Scheme 574

Scheme 575

Scheme 576

Scheme 577

1. Disconnect the negative battery cable.
2. Drain the cooling system.
3. Remove the engine cooling fan assembly.
4. Remove the generator mounting bracket.
5. Remove the generator mounting bracket stud from the cylinder head.
6. Remove the lower intake manifold. Refer to «Intake Manifold Replacement - Lower»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
7. Remove the exhaust manifold. Refer to «EXHAUST MANIFOLD REMOVAL - RIGHT»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__exhaust-manifold-removal-right) .
8. Remove the oil level indicator and tube. Refer to «Oil Level Indicator and Tube Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
9. Remove the spark plug wire harness and spark plug wire support.
10. Remove the bolt and the ground strap from the rear of the cylinder head.
11. Remove the bolt and the ground wires from the rear of the cylinder head.
12. Secure the ground strap and the ground wires out of the way.
13. Remove the valve pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
14. Remove the spark plugs.
15. Remove the cylinder head bolts. NOTE: After removal, place the cylinder head on two wood blocks to prevent damage.
16. Remove the cylinder head.
17. Remove and discard the cylinder head gasket.
18. Remove the dowel pins (cylinder head locator) (if required).
19. Clean the engine block and the cylinder head sealing surfaces. NOTE: Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.
20. Clean the cylinder head bolts and the engine block bolt holes.
21. For further service to the cylinder head refer to the following: Refer to «CYLINDER HEAD DISASSEMBLE»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__cylinder-head-disassemble) . Refer to «CYLINDER HEAD CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__cylinder-head-cleaning-inspection) . Refer to «VALVE GUIDE REAMING/VALVE & SEAT GRINDING»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__valve-guide-reamingvalve-seat-grinding) . Refer to «CYLINDER HEAD ASSEMBLE»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__cylinder-head-assemble) .

Scheme 578

Scheme 579

Scheme 580

Scheme 581

Scheme 582

Scheme 583

Scheme 584

1. Clean the cylinder head gasket surfaces on the engine block.
2. Inspect the dowel pins (cylinder head locator) for proper installation
3. Clean the cylinder head gasket surfaces on the cylinder head. Important: Do not use any type sealer on the cylinder head gasket (unless specified).
4. Install the NEW cylinder head gasket in position over the dowel pins (cylinder head locator).
5. Install the cylinder head onto the engine block. Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.
6. Apply sealant GM P/N 12346004 or equivalent to the threads of the cylinder head bolts.
7. Install the cylinder head bolts finger tight.
8. Tighten the cylinder head bolts in sequence on the first pass. Tighten Tighten the bolts in sequence on the first pass to 30 N.m (22 lb ft).
9. Use the J 36660-A in order to tighten the cylinder head bolts in sequence on the final pass. Tighten Rotate the long bolts (1, 4, 5, 8, and 9) an additional 75 degrees. Rotate the medium bolts (12 and 13) an additional 65 degrees. Rotate the short bolts (2, 3, 6, 7, 10, and 11) an additional 55 degrees.
10. Install the valve pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
11. Install the lower intake manifold. Refer to «Intake Manifold Replacement - Lower»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
12. Install the spark plug wire harness and the spark plug wire support and bolts. Tighten Tighten only the rear spark plug wire support bolt to 12 N.m (106 lb in).
13. Remove the front spark plug wire support bolt. The front spark plug wire support bolt is used to fasten the oil level indicator tube, and will be installed within the oil level indicator tube installation procedure.
14. Install the spark plugs.
15. Install the oil level indicator tube and indicator. Refer to «Oil Level Indicator and Tube Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
16. Install the exhaust manifold. Refer to «EXHAUST MANIFOLD INSTALLATION - RIGHT»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) .
17. Install the bolt and the ground wires to the rear of the cylinder head. Tighten Tighten the ground wire bolt to 35 N.m (26 lb ft).
18. Install the bolt and the ground strap to the rear of the cylinder head. Tighten Tighten the ground strap bolt to 35 N.m (26 lb ft).
19. Install the stud for the generator mounting bracket. Tighten Tighten the generator mounting bracket stud to 20 N.m (15 lb ft).
20. Install the generator mounting bracket.
21. Install the engine cooling fan assembly.
22. Fill the cooling system.
23. Connect the negative battery cable.

J 23523-F Balancer Remover and Installer

Scheme 585

Scheme 586

Scheme 587

Scheme 588

1. Disconnect the negative battery cable.
2. Remove the fan shroud assembly.
3. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) . NOTE: To prevent damage to the end of the crankshaft when using a crankshaft balancer removal tool install a bolt in the crankshaft. Use a shorter bolt with the same threads as the crankshaft balancer bolt. This bolt will allow a place for the tool to push against. The shorter bolt is to keep from going past the threads in the crankshaft and damaging the crankshaft threads.
4. Remove the crankshaft balancer bolt and washer.
5. Remove the bolts and the crankshaft pulley.
6. Use the J 23523-F in order to remove the crankshaft balancer. 6.1. Install the J 23523-F plate and bolts onto the crankshaft balancer. Tighten Tighten the bolts to 25 N.m (18 lb ft). 6.2. Install the J 23523-F forcing screw into the plate. 6.3. Rotate the J 23523-F forcing screw clockwise in order to remove the crankshaft balancer.
7. Remove the J 23523-F from the crankshaft balancer.
8. Note the position and length of any front groove pins (crankshaft balancer) (if applicable).
9. Clean the crankshaft balancer in cleaning solvent.
10. Dry the crankshaft balancer with compressed air.
11. Inspect the crankshaft balancer for the following: Loose or improperly installed front groove pin (1) (crankshaft balancer) A properly installed front groove pin should be installed until flush or below flush with the face of the crankshaft balancer. Important: A crankshaft front oil sealing surface with excessive scoring, grooves, rust, or other damage must be replaced. Worn, grooved, or damaged crankshaft front oil sealing surface (2) Minor imperfections on the crankshaft balancer crankshaft front oil seal surface may be removed with a polishing compound or fine grade emery cloth. Worn, chunking, or deteriorated rubber (3) between the hub and the outer ring Worn or damaged keyway (4) Worn or damaged bolt hole threads (5)

Scheme 589

Scheme 590

Scheme 591

Scheme 592

Scheme 593

1. Apply a small amount of grease to the crankshaft front cover oil seal sealing surface if reusing the seal. Look to ensure that the front groove pin (crankshaft balancer) is installed in the proper location (if applicable). The length and location of the pins must be the same as the original length and location 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.
2. Apply a small amount of adhesive GM P/N 12346141 or equivalent onto the crankshaft balancer keyway in order to seal the crankshaft balancer keyway and crankshaft joint.
3. Align the keyway of the crankshaft balancer with the crankshaft balancer key.
4. Install the crankshaft balancer onto the end of the crankshaft.
5. Use the J 23523-F in order to press the crankshaft balancer onto the crankshaft. 5.1. Install the J 23523-F plate and bolts onto the front of the crankshaft balancer. Tighten Tighten the J 23523-F plate bolts to 25 N.m (18 lb ft). 5.2. Install the J 23523-F screw into the end for the crankshaft. 5.3. Install the J 23523-F bearing, the washer, and the nut onto the screw. 5.4. Rotate the J 23523-F nut clockwise until the crankshaft balancer hub is completely seated against the crankshaft position sensor reluctor ring.
6. Remove the J 23523-F.
7. Install the crankshaft pulley and bolts. Tighten Tighten the crankshaft pulley bolts to 58 N.m (43 lb ft).
8. Ensure that the crown of the crankshaft balancer washer (2) is faced away from the engine.
9. Install the crankshaft balancer washer and the bolt. Tighten Tighten the crankshaft balancer bolt to 95 N.m (70 lb ft).
10. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
11. Install the fan shroud assembly.
12. Connect the negative battery cable.

J 35468 Cover Aligner/Seal Installer

Scheme 594

1. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Use a suitable prying tool to remove the crankshaft front oil seal.
3. Inspect engine front cover seal bore area for damage.
4. Inspect the crankshaft balancer seal area. Refer to «CRANKSHAFT BALANCER CLEANING AND INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) .

Scheme 595

1. Lubricate the exterior of the seal with clean engine oil.
2. Use the J 35468 with a hammer in order to install the crankshaft front oil seal.
3. Inspect to ensure the crankshaft front oil seal is flush and square to the engine front cover.
4. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

Scheme 596

Scheme 597

Scheme 598

1. Remove the engine oil pan Refer to «Oil Pan Replacement (2WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) or «Oil Pan Replacement (4WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Disconnect the crankshaft position (CKP) sensor electrical connector.
3. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
4. Remove the water pump. Refer to «WATER PUMP REMOVAL»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__water-pump-removal) .
5. Remove the CKP sensor.
6. Remove the crankshaft position sensor seal (O-ring).
7. Discard the crankshaft position sensor seal (O-ring).
8. Remove the engine front cover bolts. Important: After the composite engine front cover is removed do not reinstall the engine front cover. Always install a NEW engine front cover.
9. Remove the engine front cover.
10. Discard the engine front cover.
11. Clean all sealing surfaces.

Important: Once the composite engine front cover is removed DO NOT reinstall the engine front cover. Always install a NEW engine front cover.

Scheme 599

Scheme 600

Scheme 601

1. Install the NEW engine front cover.
2. Install the engine front cover bolts. Tighten Tighten the bolts to 12 N.m (106 lb in). Important: DO NOT reuse the original crankshaft position sensor seal (O-ring). When installing the crankshaft position sensor be sure the crankshaft position sensor is fully seated and held stationary in the engine front cover crankshaft position sensor bore. A crankshaft position sensor that is not completely seated will cock in the engine front cover and may result in erratic engine operation
3. Lubricate the NEW crankshaft position sensor seal (O-ring) with clean engine oil.
4. Install the NEW crankshaft position sensor seal (O-ring) onto the crankshaft position sensor.
5. Install the CKP sensor.
6. Install the engine oil pan. Refer to «Oil Pan Replacement (2WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) or «Oil Pan Replacement (4WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
7. Connect the CKP sensor electrical connector.
8. Install the water pump. Refer to «WATER PUMP INSTALLATION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__water-pump-installation) .
9. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

J 5590 Crankshaft Gear Installer

Scheme 602

1. Remove the engine front cover. Refer to «Engine Front Cover Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the crankshaft position sensor reluctor ring.

Note. Failure to properly align the crankshaft position sensor reluctor ring may result in component damage and effect OBD II system performance.

Important: The reluctor ring is shaped like a dish. The dish must face the engine front cover. Failure to do so will damage the front cover and the reluctor ring.

Scheme 603

1. Install the crankshaft position sensor reluctor ring. 1.1. Align the keyway on the crankshaft position sensor reluctor ring with the crankshaft balancer key in the crankshaft. 1.2. Use the J 5590 in order to push the crankshaft position sensor reluctor ring onto the crankshaft until completely seated against the crankshaft sprocket.
2. Install the engine front cover. Refer to «Engine Front Cover Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

1. J 5825-A Crankshaft Gear Remover
2. J 5590 Crankshaft Gear Installer

Scheme 604

Scheme 605

Scheme 606

Scheme 607

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Scheme 609

Scheme 610

Scheme 611

1. Remove the engine front cover. Refer to «Engine Front Cover Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the crankshaft position sensor reluctor ring. NOTE: In order to rotate the engine install a bolt with the same threads as the crankshaft, but do not use the crankshaft balancer bolt or a bolt longer than 1 inch, in the crankshaft. Failing to do so will cause damage to the bolt threads and the crankshaft threaded hole when removing the bolt.
3. Install a 7/16-20 x 1 inch bolt into the end of the crankshaft. NOTE: Align the timing marks before removing the timing chain. If it is necessary to turn either the camshaft or the crankshaft with the timing chain removed, loosen or remove the valve rocker arms. Turning either the crankshaft or camshaft with the timing chain removed may cause the pistons to contact the valves, resulting in damage.
4. Rotate the crankshaft until: 4.1. The timing marks on both sprockets line up. 4.2. The number four cylinder is at top dead center (TDC) of the compression stroke.
5. Remove the camshaft sprocket bolts.
6. Remove the camshaft sprocket and the camshaft timing chain.
7. Remove the crankshaft sprocket using the J 5825-A.
8. Remove the crankshaft balancer key.
9. Clean the components with cleaning solvent.
10. Dry the components with compressed air.
11. Inspect the camshaft timing chain for binding or wear.
12. Inspect the camshaft sprocket and the crankshaft sprocket for: Broken teeth (1) Damaged teeth (2) Chipped teeth (3) Worn teeth Uneven wear on the edge of the teeth Worn valleys between the sprocket teeth Crankshaft sprocket keyway for wear

Scheme 612

Scheme 613

Scheme 614

Scheme 615

Scheme 616

Scheme 617

1. Install the crankshaft balancer key into the crankshaft keyway. The crankshaft balancer key should be parallel to the crankshaft or with a slight incline.
2. Align the keyway of the crankshaft sprocket with the crankshaft balancer key.
3. Use the J 5590 in order to install the crankshaft sprocket. Important: Install the camshaft sprocket with the alignment mark at the 6 o'clock position
4. Install the camshaft sprocket and the camshaft timing chain
5. Look to ensure that the crankshaft sprocket is aligned at the 12 o'clock position and camshaft sprocket is aligned at the 6 o'clock position Important: Do not use a hammer to install the camshaft sprocket onto the camshaft. To do so may dislodge the expansion cup plug (camshaft rear bearing hole).
6. Install camshaft sprocket bolts. Tighten Tighten the camshaft sprocket bolts to 25 N.m (18 lb ft).
7. Install the crankshaft position sensor reluctor ring. 7.1. Align the keyway on the crankshaft position sensor reluctor ring with the crankshaft balancer key in the crankshaft. 7.2. Use the J 5590 in order to push the crankshaft position sensor reluctor ring onto the crankshaft until completely seated against the crankshaft sprocket. 7.3. Remove the bolt that was installed in the end of the crankshaft. 7.4. Install the engine front cover. Refer to «Engine Front Cover Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

1. J 8092 Universal Driver Handle
2. J 36660-A Electronic Torque Angle Meter
3. J 36996 Balance Shaft Installer

Scheme 618

Scheme 619

Scheme 620

Scheme 621

1. Remove the radiator.
2. Remove the A/C condenser. Refer to appropriate A/C article.
3. Remove the valve lifter pushrod guide. Refer to «Valve Lifter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
4. Remove the timing chain and camshaft sprockets. Refer to «Timing Chain and Sprockets Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
5. Remove the balance shaft drive gear. Important: The balance shaft drive and balance shaft driven gears are serviced as a set. The set includes the balance shaft driven gear bolt.
6. Remove the balance shaft driven gear bolt from the balance shaft. 6.1. Use a wrench in order to secure the balance shaft. Place the wrench onto the balance shaft near to the balance shaft front bearing. 6.2. Remove the balance shaft bolt. 6.3. Remove the wrench from the balance shaft.
7. Remove the balance shaft driven gear from the balance shaft.
8. Remove the bolts and the balance shaft retainer. Important: The balance shaft and the balance shaft front bearing are serviced only as a package. Do not remove the balance shaft front bearing from the balance shaft.
9. Use a soft-faced hammer in order to remove the balance shaft from the engine block.
10. Clean and inspect the balance shaft. Refer to «BALANCE SHAFT CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__balance-shaft-cleaning-inspection) .

Important: The balance shaft and the balance shaft front bearing are serviced only as an assembly. Do not remove the balance shaft front bearing from the balance shaft.

Scheme 622

Scheme 623

Scheme 624

Scheme 625

Scheme 626

Scheme 627

Scheme 628

1. Apply clean engine oil GM P/N 12345610 or equivalent to the balance shaft front bearing.
2. Use the J 36996 and the J 8092 in order to install the balance shaft.
3. Install the balance shaft retainer and bolts. Tighten Tighten the bolts to 12 N.m (106 lb in).
4. Install the balance shaft driven gear onto the balance shaft.
5. If reusing the fastener, apply threadlock GM P/N 12345382 or equivalent to the threads of the balance shaft driven gear bolt.
6. Install the balance shaft driven gear bolt. 6.1. Use a wrench to secure the balance shaft. Place the wrench onto the balance shaft near to the balance shaft front bearing. 6.2. Install the balance shaft driven gear bolt. Tighten Tighten the balance shaft driven gear bolt to 20 N.m (15 lb ft). Using the J 36660-A rotate the balance shaft driven gear bolt an additional 35 degrees.
7. Remove the wrench from the balance shaft.
8. Rotate the balance shaft by hand in order to ensure that there is clearance between the balance shaft and the valve lifter pushrod guide. If the balance shaft does not rotate freely, check to ensure that the retaining ring on the balance shaft front bearing is seated on the case.
9. Install the balance shaft drive gear. DO NOT install the camshaft sprocket bolts at this time.
10. Rotate the engine camshaft so that the timing mark on the balance shaft drive gear is in the 12 o'clock position
11. Remove the balance shaft drive gear.
12. Rotate the balance shaft so that the timing mark on the balance shaft driven gear is in the 6 o'clock position
13. Position the balance shaft drive gear onto the engine camshaft.
14. Look to ensure that the balance shaft drive gear and the balance shaft driven gear timing marks are aligned.
15. Install the timing chain and the camshaft sprocket. Refer to «Timing Chain and Sprockets Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
16. Install the engine front cover. Refer to «Engine Front Cover Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
17. Install the valve lifter pushrod guide. Refer to «Valve Lifter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
18. Install the A/C condenser.
19. Install the radiator.

1. J 26941 Bushing/Bearing Remover
2. J 38834 Balance Shaft Service Kit

Important: The balance shaft and the front bearing are serviced only as a package. Do not remove the bearing from the balance shaft.

1. Remove the balance shaft. Refer to «Balance Shaft Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Use the J 26941 and the J 38834 in order to remove the balance shaft rear bearing. 2.1. Install J 26941 legs behind the balance shaft rear bearing and secure. 2.2. Install the J 38834-1 with the short threaded end through the balance shaft bore in the front of the engine block. 2.3. Install the J 38834-1 into J 26941. 2.4. Slide the J 38834-2 onto the J 38834-1 and into the balance shaft bore of the engine block. 2.5. Install the J 38834 bearing, washer, and nut onto the J 38834-1. 2.6. Using a wrench secure the J 38834-1 and then rotate the J 38834 nut clockwise until the balance shaft rear bearing is removed from the engine block. 2.7. Remove the J 26941 from the balance shaft rear bearing.
3. Discard the balance shaft rear bearing.

Scheme 629

1. Use the J 38834 in order to install the balance shaft rear bearing. 1.1. Install the J 38834-3 onto the short threaded end of the J 38834-1. 1.2. Install the J 38834 nut, the washer, and the bearing on the long threaded end of the J 38834-1. 1.3. Install the J 38834-2 onto the J 38834-1 so that the smaller diameter of the J 38834-2 will be facing the front of the engine block. 1.4. Install the J 38834-2 on the inside of the balance shaft front bearing bore. 1.5. Lubricate the NEW balance shaft rear bearing with clean engine oil. 1.6. Install the balance shaft rear bearing onto the J 38834-2. 1.7. Align the balance shaft rear bearing for installation 1.8. Using a wrench secure the J 38834-1 into place. 1.9. Rotate the J 38834 nut until the balance shaft rear bearing is properly and completely pushed into the balance shaft rear bearing bore.
2. Remove the J 38834.
3. Install the balance shaft. Refer to «Balance Shaft Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

Scheme 630

Scheme 631

1. Disconnect the negative battery cable.
2. Drain the cooling system.
3. Remove the radiator.
4. Remove the A/C condenser.
5. Remove the valve lifters. Refer to «Valve Lifter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
6. Remove the timing chain and the camshaft sprocket. Refer to «Timing Chain and Sprockets Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
7. Remove the balance shaft drive gear.
8. Remove the camshaft retainer bolts and retainer. NOTE: All camshaft journals are the same diameter, so care must be used in removing or installing the camshaft to avoid damage to the camshaft bearings.
9. Remove the engine camshaft. 9.1. Install the three 5/16-18 x 4.0 inch bolts into the engine camshaft front bolt holes. 9.2. Using the bolts as a handle, carefully rotate and pull the engine camshaft out of the camshaft bearings. 9.3. Remove the bolts from the front of the engine camshaft. 9.4. Clean and inspect the camshaft and the bearings. Refer to «CAMSHAFT & BEARINGS CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__camshaft-bearings-cleaning-inspection) .

Important: Whenever a new camshaft is installed, do the following procedures

1. Change the engine oil.
2. Change the engine oil filter.
3. Add GM Engine Oil Supplement GM P/N 1052367 or the equivalent to the engine oil.

Scheme 632

1. Apply clean engine oil GM P/N 12345610 or equivalent, or engine oil supplement GM P/N 1052367 or equivalent to the following components: The engine camshaft lobes The camshaft bearing journals The camshaft bearings
2. Install three 5/16-18 x 4.0 inch bolts into the engine camshaft front bolt holes. NOTE: All camshaft journals are the same diameter, so care must be used in removing or installing the camshaft to avoid damage to the camshaft bearings.
3. Use the bolts as a handle in order to install the engine camshaft.
4. Remove the 3 bolts from the front of the engine camshaft.
5. If reusing the fasteners, apply threadlock GM P/N 12345382 or equivalent to the threads of the camshaft retainer bolts.
6. Install the camshaft retainer and bolts. Tighten Tighten the camshaft retainer bolts to 12 N.m (106 lb in).
7. Install the balance shaft drive gear. Refer to «BALANCE SHAFT INSTALLATION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__balance-shaft-installation) , for alignment of the balance shaft drive gear and the driven gear.
8. Install the timing chain and camshaft sprocket. Refer to «Timing Chain and Sprockets Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
9. Install the valve lifters. Refer to «Valve Lifter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
10. Install the A/C condenser.
11. Install the radiator.
12. Fill the cooling system.
13. Recharge the air conditioning system.
14. Connect the negative battery cable.

1. Raise and support the vehicle.
2. Position a suitable container to catch the engine oil.
3. Remove the engine oil filter.
4. Remove the engine oil cooler pipes from the remote engine oil filter adapter.
5. Remove the remote oil filter inlet and outlet hoses from the remote oil filter adapter. Refer to «Remote Oil Filter Adapter Pipe Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
6. Remove the nuts and the remote oil filter adapter from the remote oil filter mounting bracket.
7. If necessary, remove the remote oil filter adapter mounting bracket and bolts from the radiator support.

1. Install the remote oil filter adapter mounting bracket and bolts to the radiator support, if removed. Tighten Tighten the remote oil filter adapter mounting bracket bolts to 30 N.m (22 lb ft).
2. Install the remote oil filter adapter and nuts to the mounting bracket. Tighten Tighten the remote oil filter adapter nuts to 25 N.m (18 lb ft).
3. Install the remote oil filter inlet and outlet hoses to the remote oil filter adapter. Refer to «Remote Oil Filter Adapter Pipe Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
4. Install the engine oil cooler pipes to the remote engine oil filter adapter.
5. Install the engine oil filter. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
6. Lower the vehicle.
7. Operate the engine and check for leaks.
8. Inspect the engine oil level and fill to the proper level.

Scheme 633

Scheme 634

Scheme 635

1. Raise and support the vehicle.
2. Remove the steering linkage shield, if equipped.
3. Position a suitable drain pan for the engine oil to drain into when the hoses are removed.
4. Remove the remote oil filter inlet and outlet hose clip bolt from the oil pan
5. Remove the bolt attaching the remote oil filter inlet and outlet hoses to the remote oil filter adapter.
6. Remove the remote oil filter inlet and outlet hoses and the seals from the remote oil filter adapter.
7. Discard the remote oil filter inlet and outlet hose seals.
8. Remove the bolt attaching the remote oil filter inlet and outlet hoses to the oil filter pipe adapter.
9. Remove the remote oil filter inlet and outlet hoses.
10. Remove and discard the remote oil filter inlet and outlet hose seals.
11. Clean and inspect the remote engine oil filter inlet and outlet hoses and fittings.

Scheme 636

Scheme 637

Scheme 638

Scheme 639

1. Install NEW seals on both ends of the remote oil filter inlet and outlet hoses.
2. Install the remote oil filter inlet and outlet hoses and the bolt to the oil filter pipe adapter. Tighten Tighten the remote oil filter inlet and outlet hose to remote oil filter pipe adapter bolt to 35 N.m (26 lb ft).
3. Install the remote oil filter inlet and outlet hoses to the remote oil filter adapter. Tighten Tighten the remote oil filter inlet and outlet hose to the remote oil filter adapter bolt to 35 N.m (26 lb ft).
4. Install the remote oil filter inlet and outlet clip and bolt to the oil pan Tighten Tighten the remote oil filter inlet and outlet hose clip bolt to 10 N.m (89 lb in).
5. Install the steering linkage shield, if equipped.
6. Lower the vehicle.
7. Operate the engine and check for leaks.
8. Inspect the engine oil level and fill to the proper level.

Scheme 640

Scheme 641

Scheme 642

Scheme 643

1. Raise and support the vehicle.
2. Position a suitable container to catch the engine oil.
3. Remove the engine oil cooler pipe bolt from the oil filter adapter.
4. Remove the engine oil cooler adapter pipes and seals from the oil filter adapter.
5. Remove the engine oil filter (except Four Wheel Drive vehicle).
6. Remove oil filter adapter bolts.
7. Remove the oil filter adapter and the oil filter adapter gasket.
8. Discard the oil filter adapter gasket.
9. Remove the oil filter adapter seal (O-ring).
10. Discard the oil filter adapter seal (O-ring).

Scheme 644

Scheme 645

Scheme 646

Scheme 647

1. Install the new oil filter adapter seal (O-ring) into the groove on the oil filter adapter.
2. Install the oil filter adapter and a new oil filter adapter gasket.
3. Install the oil filter adapter bolts. Tighten Tighten the oil filter adapter bolts to 21 N.m (15 lb ft).
4. Install the oil filter adapter pipe seals and pipes to the oil filter adapter.
5. Install the oil filter adapter pipe bolt. Tighten Tighten the oil filter adapter pipe bolt to 35 N.m (26 lb ft).
6. Install the engine oil filter (except Four Wheel Drive vehicles). Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
7. Lower the vehicle.
8. Operate the engine and check for leaks.
9. Inspect the engine oil level and fill to the proper level.

Scheme 648

1. Raise and support the vehicle.
2. Position a suitable container to catch the engine oil.
3. Remove the oil filter (2WD vehicle).
4. Remove the oil filter adapter. Refer to «Oil Filter Adapter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
5. Using a suitable prying tool remove the oil filter bypass valve.
6. Clean and inspect valve bore for damage.

Scheme 649

1. Install a NEW oil filter bypass valve using the following procedure: 1.1. Use a brass drift that is the same diameter as the outside diameter of the oil filter bypass valve. 1.2. Install the oil filter bypass valve into the oil gallery bore until slightly below flush with the surface of the engine block. 1.3. Using a pointed punch, stake the engine block area around the oil filter bypass valve. Stake in 3 locations 120 degrees apart.
2. Install the oil filter adapter (RWD vehicle) or the remote oil filter pipe adapter (4WD vehicle). Refer to «Oil Filter Adapter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
3. Install the oil filter (RWD vehicle). Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
4. Lower the vehicle.

Scheme 650

Scheme 651

Scheme 652

Scheme 653

1. Remove the engine. Refer to «Engine Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the oil pan drain plug and drain the engine oil into a suitable container. Important: The low oil level sensor is not reusable. Use a NEW low oil sensor.
3. Remove and discard the engine oil level sensor (if applicable).
4. Remove the oil pan bolts and nuts.
5. Remove the oil pan
6. Remove the oil pan gasket.
7. Discard the oil pan gasket.
8. Clean all sealing surfaces on the engine and the oil pan Refer to «OIL PAN CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) .

Note. Any time the transmission and the engine oil pan are off of the engine at the same time, install the transmission before the oil pan. This is to allow for the proper oil pan alignment. Failure to achieve the correct oil pan alignment can result in transmission failure.

Scheme 654

Scheme 655

Scheme 656

Scheme 657

Scheme 658

Scheme 659

Scheme 660

Scheme 661

1. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive GM P/N 12346141 or equivalent to both the right and left sides of the engine front cover to engine block junction at the oil pan sealing surfaces.
2. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive GM P/N 12346141 or equivalent to both the right and left sides of the crankshaft rear oil seal housing to engine block junction at the oil pan sealing surfaces. Important: Always install a NEW oil pan gasket. The oil pan gasket and oil pan must be installed and the fasteners tightened while the adhesive is still wet to the touch.
3. Install the NEW oil pan gasket into the groove in the oil pan Important: The oil pan alignment must always be flush or forward no more than 0.3 mm (0.011 in) from the rear face of the engine block.
4. Install the oil pan onto the engine block. Press the oil pan gasket into the grooves of the engine front cover and crankshaft rear oil seal housing.
5. Slide the oil pan back against a suitable straight edge.
6. Install the oil pan bolts and nuts, but do not tighten.
7. Measure the pan-to-transmission housing clearance using a feeler gage and a straight edge. Use a feeler gage to check the clearance between the oil pan-to-transmission housing measurement points. If the clearance exceeds 0.3 mm (0.011 in) at any of the 3 oil pan-to-transmission housing measurement points (1), then repeat the step until the oil pan-to-transmission housing clearance is within the specification. The oil pan must always be forward of the rear face of the engine block.
8. Tighten the oil pan bolts and nuts in sequence. Tighten Tighten the oil pan bolts to 25 N.m (18 lb ft).
9. Measure the clearance between the 3 oil pan-to-transmission housing measurement points in order to ensure proper alignment.
10. Install a NEW oil pan drain plug seal (O-ring) onto the oil pan drain plug.
11. Install the oil pan drain plug into the oil pan. Tighten Tighten the oil pan drain plug to 25 N.m (18 lb ft). Important: The low oil level sensor is not reusable. Use a NEW low oil sensor.
12. Install the NEW engine oil level sensor (if applicable). Tighten Tighten the engine oil level sensor to 13 N.m (115 lb in).
13. Install the engine. Refer to «Engine Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
14. Fill the engine with oil. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

Scheme 662

Scheme 663

Scheme 664

Scheme 665

Scheme 666

Scheme 667

Scheme 668

Scheme 669

Scheme 670

1. Disconnect the negative battery cable.
2. Remove the oil level indicator.
3. Remove the front differential assembly. Refer to appropriate DIFFERENTIAL article.
4. Remove the starter. Refer to appropriate STARTER article.
5. Remove the transmission cover.
6. Remove the oil pan drain plug and drain the engine oil into a suitable container.
7. Remove the remote oil filter pipe adapter. Refer to «Oil Filter Adapter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
8. Remove the bolt holding the remote oil filter inlet and outlet hose clip to the oil pan
9. Remove the stud holding the bracket for the starter wire harness and if equipped, the transmission oil cooler pipes.
10. Remove the access plugs for the oil pan rear nuts.
11. Remove the transmission to oil pan bolts (automatic transmission shown). Important: The low oil level sensor is not reusable. Use a NEW low oil sensor.
12. Remove and discard the engine oil level sensor (if applicable).
13. Remove the oil pan bolts and nuts.
14. Remove the oil pan
15. Remove the oil pan gasket.
16. Discard the oil pan gasket.
17. Clean all sealing surfaces on the engine and the oil pan Refer to «OIL PAN CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) .

Note. Any time the transmission and the engine oil pan are off of the engine at the same time, install the transmission before the oil pan This is to allow for the proper oil pan alignment. Failure to achieve the correct oil pan alignment can result in transmission failure.

Scheme 671

Scheme 672

Scheme 673

Scheme 674

Scheme 675

Scheme 676

Scheme 677

Scheme 678

Scheme 679

Scheme 680

Scheme 681

Scheme 682

1. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive GM P/N 12346141 or equivalent to both the right and left sides of the engine front cover to engine block junction at the oil pan sealing surfaces.
2. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive GM P/N 12346141 or equivalent to both the right and left sides of the crankshaft rear oil seal housing to engine block junction at the oil pan sealing surfaces. Important: Always install a NEW oil pan gasket. The oil pan gasket and oil pan must be installed and the fasteners tightened while the adhesive is still wet to the touch.
3. Install the NEW oil pan gasket into the groove in the oil pan Important: The oil pan alignment must always be flush or forward no more than 0.3 mm (0.011 in) from the rear face of the engine block.
4. Install the oil pan onto the engine block. Press the oil pan gasket into the grooves of the engine front cover and crankshaft rear oil seal housing.
5. Slide the oil pan back against a suitable straight edge.
6. Install the oil pan bolts and nuts, but do not tighten
7. Measure the pan-to-transmission housing clearance using a feeler gage and a straight edge. Use a feeler gage to check the clearance between the oil pan-to-transmission housing measurement points. If the clearance exceeds 0.3 mm (0.011 in) at any of the 3 oil pan-to-transmission housing measurement points (1), then repeat the step until the oil pan-to-transmission housing clearance is within the specification The oil pan must always be forward of the rear face of the engine block.
8. Tighten the oil pan bolts and nuts in sequence. Tighten Tighten the oil pan bolts to 25 N.m (18 lb ft).
9. Measure the clearance between the 3 oil pan-to-transmission housing measurement points in order to ensure proper alignment.
10. Install a NEW oil pan drain plug seal (O-ring) onto the oil pan drain plug.
11. Install the oil pan drain plug into the oil pan. Tighten Tighten the oil pan drain plug to 25 N.m (18 lb ft). Important: The low oil level sensor is not reusable. Use a NEW low oil sensor.
12. Install the NEW engine oil level sensor (if applicable). Tighten Tighten the engine oil level sensor to 13 N.m (115 lb in). NOTE: Any time the transmission and the engine oil pan are off of the engine at the same time, install the transmission before the oil pan This is to allow for the proper oil pan alignment. Failure to achieve the correct oil pan alignment can result in transmission failure.
13. Install the transmission to oil pan bolts. Tighten Tighten the transmission to the oil pan bolts to 47 N.m (35 lb ft).
14. Install the access plugs for the oil pan rear nuts.
15. Install the stud holding the bracket for the starter wire harness and if equipped, the transmission oil cooler pipes. Tighten Tighten the bracket stud to 9 N.m (80 lb in).
16. Install the remote oil filter pipe adapter. Refer to «Oil Filter Adapter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
17. Install the bolt holding the oil filter inlet and outlet hose clip to the oil pan. Tighten Tighten the hose clip bolt to 10 N.m (88 lb in).
18. Install the transmission cover and bolts. Tighten Tighten the transmission cover bolts to 12 N.m (106 lb in).
19. Install the starter motor. Refer to appropriate STARTER article.
20. Install the front differential assembly.
21. Install the oil level indicator.
22. Fill the engine with engine oil. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
23. Connect the negative battery cable.

J 41712 Oil Pressure Switch Socket

Important: Clean the area around the sensor and Distributor before removal. Do not allow debris to enter the engine.

Scheme 683

Scheme 684

1. Remove the distributor.
2. Disconnect the engine oil pressure sensor electrical connector.
3. Remove the engine oil pressure sensor using the J 41712. Important: Note the alignment of the engine oil pressure sensor fitting prior to removal.
4. Remove the engine oil pressure sensor fitting, if necessary.

Scheme 685

Scheme 686

1. Apply sealant GM P/N 12346004 or equivalent to the threads of the fitting and/or the engine oil pressure sensor.
2. Install the engine oil pressure sensor fitting, if removed. Tighten Tighten the engine oil pressure sensor fitting to 15 N.m (11 lb ft).
3. Install the engine oil pressure sensor. Tighten Using the J 41712, tighten the engine oil pressure sensor to 30 N.m (22 lb ft).
4. Connect the engine oil pressure sensor electrical connector.
5. Install the distributor.
6. Check and adjust engine oil level.

Scheme 687

Scheme 688

1. Remove the oil level indicator.
2. Remove the right exhaust manifold. Refer to «EXHAUST MANIFOLD REMOVAL - RIGHT»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair__exhaust-manifold-removal-right) .
3. Remove the oil level indicator tube bolt.
4. Remove the oil level indicator tube from the engine using a twisting motion
5. Clean the old sealer from the oil level indicator tube and the engine block.

Scheme 689

Scheme 690

1. Apply sealant GM P/N 12346004 or equivalent around the oil level indicator tube 13 mm (0.5 in) below the tube bead.
2. Install the oil level indicator tube into the engine block. Rotate the oil level indicator tube into position
3. Install the oil level indicator tube bolt. Tighten Tighten the oil level indicator tube bolt to 12 N.m (106 lb in).
4. Install the right exhaust manifold. Refer to «EXHAUST MANIFOLD INSTALLATION - RIGHT»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) .
5. Install the oil level indicator.

Scheme 691

Scheme 692

Scheme 693

1. Remove the oil pan Refer to «Oil Pan Replacement (2WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) or «Oil Pan Replacement (4WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the oil pump bolt.
3. Remove the oil pump.
4. Inspect the pins (oil pump locator) for damage, and replace the pins if required.
5. Clean and inspect all parts. Refer to «OIL PUMP CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) .

Scheme 694

Scheme 695

Scheme 696

1. Inspect for properly installed pins (oil pump locator). Important : Do not reuse the oil pump driveshaft retainer. During assembly, install a NEW oil pump driveshaft retainer.
2. Install the oil pump.
3. Position the oil pump onto the pins.
4. Install the oil pump bolt attaching the oil pump to the rear crankshaft bearing cap. Tighten Tighten the oil pump bolt to 90 N.m (66 lb ft).
5. Install the oil pan Refer to «Oil Pan Replacement (2WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) or «Oil Pan Replacement (4WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

J 35621-B Rear Main Seal Installer

1. Remove the transmission assembly. Refer to TRANSMISSION for Automatic Transmission - 4L60-E. Refer to TRANSMISSION REPLACEMENT for Manual Transmission - NV 3500.
2. Remove the engine flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
3. Remove the crankshaft rear oil seal from the crankshaft rear oil seal housing. Insert a suitable tool into the access notches and then carefully pry the crankshaft rear oil seal from the crankshaft rear oil seal housing.
4. Discard the crankshaft rear oil seal.
5. Clean off any dirt or rust in the area.

Scheme 697

1. Apply a small amount (2 to 3 drops) of clean engine oil to the bore of the crankshaft rear oil seal housing.
2. Apply a small amount (2 to 3 drops) of clean engine oil to the outside diameter of the engine flywheel pilot flange.
3. Apply a small amount (1 drop) of clean engine oil to the outside diameter of the flywheel locator pin
4. Apply a small amount (2 to 3 drops) of clean engine oil to the crankshaft seal surface.
5. Inspect the J 35621-B flange for imperfections that may damage the crankshaft rear oil seal. Minor imperfections may be removed with a fine grade emery cloth. Important: DO NOT allow oil or any other lubricants to contact the seal lip surface of the crankshaft rear oil seal.
6. Remove the sleeve from the crankshaft rear oil seal.
7. Apply a small amount (2 to 3 drops) of clean engine oil to the outside diameter of the crankshaft rear oil seal.
8. Install the crankshaft rear oil seal onto the J 35621-B.
9. Install the J 35621-B onto the rear of the crankshaft and hand tighten the tool bolts until snug. NOTE: Proper alignment of the crankshaft rear oil seal is critical. Install the crankshaft rear oil seal near to flush and square to the crankshaft rear oil seal housing. Failing to do so may cause the crankshaft rear oil seal or the crankshaft rear oil seal installation tool to fail.
10. Install the crankshaft rear oil seal onto the crankshaft and into the crankshaft rear oil seal housing. 10.1. Turn the J 35621-B wing nut clockwise until the crankshaft rear oil seal is installed near to flush and square to the crankshaft rear oil seal housing. Increased resistance will be felt when the crankshaft rear oil seal has reached the bottom of the crankshaft rear oil seal housing bore. 10.2. Turn the J 35621-B wing nut counterclockwise to release the J 35621-B from the crankshaft rear oil seal.
11. Remove the J 35621-B from the crankshaft.
12. Wipe off any excess engine oil with a clean rag.
13. Install the engine flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
14. Install the transmission assembly.

Important : Do not remove the crankshaft rear oil seal housing if only replacing the crankshaft rear oil seal.

Scheme 698

1. Remove the oil pan Refer to «Oil Pan Replacement (2WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) or «Oil Pan Replacement (4WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
2. Remove the transmission assembly. Refer to TRANSMISSION for Automatic Transmission - 4L60-E. Refer to TRANSMISSION REPLACEMENT for Manual Transmission - NV 3500.
3. Remove the engine flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
4. Remove the bolts and the nut holding the crankshaft rear oil seal housing to the engine.
5. Remove the crankshaft rear oil seal housing.
6. Remove and discard the crankshaft rear oil seal housing gasket.
7. Clean all the sealing surfaces.
8. Inspect and replace the crankshaft rear oil seal housing for warping, cracks, wear, or damage.

Important: When installing a NEW crankshaft rear oil seal housing the crankshaft rear oil seal will come with the housing. If reusing the housing and then installing a NEW seal follow the instructions for installing the housing and than Refer to Crankshaft Rear Oil Seal Replacement to install the seal.

Scheme 699

1. Install a NEW crankshaft rear oil seal housing gasket.
2. Install the NEW crankshaft rear oil seal housing with the oil seal to the engine block using the following procedure. Important: Do not oil or grease the seal lip or the crankshaft seal area. 2.1. Leave the sleeve in the crankshaft rear oil seal and use the sleeve as a guide to ease the seal lip over the end of the crankshaft. 2.2. Push the crankshaft rear oil seal housing fully onto the crankshaft until the crankshaft rear oil seal housing is against the crankshaft rear oil seal gasket and the engine. 2.3. Remove the sleeve.
3. Install the bolts and the nut to the crankshaft rear oil seal housing. Tighten Tighten the crankshaft rear oil seal housing bolts and nut to 12 N.m (106 lb in).
4. Install the engine flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
5. Install the transmission assembly.
6. Install the oil pan Refer to «Oil Pan Replacement (2WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) or «Oil Pan Replacement (4WD)»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .

Scheme 700

Scheme 701

1. Remove the transmission Refer to TRANSMISSION for Automatic Transmission - 4L60-E. Refer to TRANSMISSION REPLACEMENT for Manual Transmission - NV 3500.
2. Remove the clutch assembly, if equipped. Refer to appropriate CLUTCH ASSEMBLY & PILOT BEARING article.
3. Remove the engine flywheel bolts.
4. Remove the engine flywheel (automatic transmission) (1), if applicable.
5. Remove the engine flywheel (manual transmission) (2), if applicable. Important: If replacing the engine flywheel (manual transmission), then NEW flywheel weights must be installed into the NEW engine flywheel in the same location as the old flywheel weights in the old engine flywheel.
6. Note the position of any flywheel weights for assembly (if applicable).
7. Clean and inspect all parts. Refer to «ENGINE FLYWHEEL CLEANING & INSPECTION»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l-unit-repair) .

Important: If replacing the engine flywheel (manual transmission), note the position and length of the original flywheel weights (if applicable). Flywheel weights of the same length must be installed into the new engine flywheel in the same location as the old flywheel weights were in the old engine flywheel.

Scheme 702

Scheme 703

1. Note the position of the flywheel weights and install the NEW flywheel weights as required. A properly installed flywheel weight will be flush or slightly below flush with the face of the engine flywheel.
2. Install the engine flywheel (1 or 2) to the crankshaft. Align the engine flywheel locator hole to the flywheel locator pin
3. Install the engine flywheel bolts. Tighten Tighten the engine flywheel bolts in sequence to 100 N.m (74 lb ft).
4. Install the clutch assembly, if equipped.
5. Install the transmission

J 41427 Engine Lift Bracket

Note. If the engine is damaged internally and a new engine assembly is installed in the vehicle, ensure that all foreign material is flushed out of the cooling system. You must also flush out the oil cooler system. Failure to rid the oil cooler system of debris can result in engine damage.

Scheme 704

Scheme 705

Scheme 706

Scheme 707

Scheme 708

Scheme 709

Scheme 710

Scheme 711

Scheme 712

Scheme 713

Scheme 714

Scheme 715

Scheme 716

Scheme 717

Scheme 718

Scheme 719

Scheme 720

Scheme 721

Scheme 722

Scheme 723

1. Disconnect the negative battery cable.
2. Drain the cooling system.
3. Drain the engine oil. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
4. Remove the hood.
5. Raise and support the vehicle.
6. Remove the underbody shields, if equipped.
7. Remove the exhaust pipe from the exhaust manifolds.
8. Remove the engine oil cooler pipes.
9. Remove the stud holding the starter wire harness and if equipped, transmission oil cooler lines.
10. Remove the starter. Refer to appropriate STARTER article.
11. Remove the transmission cover.
12. Remove the transmission. Refer to TRANSMISSION for Automatic Transmission - 4L60-E. Refer to TRANSMISSION REPLACEMENT for Manual Transmission - NV 3500.
13. Remove the front engine mount through bolts.
14. Lower the vehicle.
15. Remove the PCV tube from the right valve rocker arm cover and the air cleaner outlet duct.
16. Disconnect the breather tube at the air cleaner outlet duct.
17. Remove the air cleaner outlet duct retaining wing nut.
18. Disconnect the intake air temperature (IAT) sensor harness connector.
19. Remove the air cleaner outlet duct from the throttle body. CAUTION: In order to avoid possible injury or vehicle damage, always replace the accelerator control cable with a NEW cable whenever you remove the engine from the vehicle. In order to avoid cruise control cable damage, position the cable out of the way while you remove or install the engine. Do not pry or lean against the cruise control cable and do not kink the cable. You must replace a damaged cable.
20. Disconnect the accelerator cable from the throttle body.
21. Remove the accelerator cable from the accelerator control cable bracket.
22. Remove the cruise control cable, if equipped from the throttle shaft and the accelerator cable bracket.
23. Remove the radiator.
24. Remove the inlet and outlet radiator hoses from the engine.
25. Disconnect the heater hoses from the engine.
26. Disconnect the power brake booster vacuum hose from the intake manifold.
27. Disconnect the vacuum hose for the A/C system, if equipped from the intake manifold.
28. Disconnect the following electrical connectors: The A/C compressor clutch (1), if equipped The A/C compressor cutoff switch (5), if equipped The TP sensor (2) The IAC valve motor (3) The ECT sensor (4)
29. Disconnect the following electrical connectors: The fuel meter body (1) The EVAP canister purge solenoid (2) The MAP sensor (3)
30. Disconnect the following electrical connectors: The ICM (1) The ignition coil (2) The EGR solenoid (3) The generator (4)
31. Disconnect the following electrical connectors: The distributor (1) The engine oil pressure sensor (2) The knock sensor (3)
32. Disconnect the CKP sensor (2) electrical connector.
33. Remove the bolt and the battery negative cable (1).
34. Remove the engine wiring harness bracket bolt (3).
35. Remove the engine wiring harness clips from the front of the engine.
36. Remove the engine wiring harness clips from the brackets.
37. Move the engine wiring harness aside.
38. Remove the generator.
39. Remove the bolt holding the ground wires to the left cylinder head.
40. Remove the bolt holding the fuel pipe bracket to the rear of left cylinder head.
41. Remove the bolts holding the ground wires to the right cylinder head.
42. Remove the bolt holding the ground strap to the right cylinder head.
43. Remove the accelerator control cable bracket from the throttle body.
44. Remove the water pump pulley.
45. Remove the A/C compressor, if equipped.
46. Remove the nut holding the AIR reactor pipe bracket to the front of the engine, if equipped.
47. Remove the nuts holding the power steering pump rear bracket to the engine.
48. Remove the power steering pump mounting bracket. The power steering pump can remain on the mounting bracket. The hoses do not require removal. Remove the three bolts and the nut. Slide the mounting bracket off of the stud. Secure the mounting bracket out of the way.
49. Remove both of the secondary air injection (AIR) reactor pipes from the engine.
50. Remove the AIR shut-off valve and hoses.
51. Remove the distributor cap.
52. Disconnect the fuel pipes at the rear of the intake manifold.
53. Disconnect the EVAP canister purge solenoid valve pipe.
54. Remove the water outlet.
55. Remove the spark plug wire harness retainer from the exhaust gas recirculation (EGR) valve inlet pipe.
56. Remove the clamp bolt for the EGR valve inlet pipe.
57. Remove the EGR valve inlet pipe from the intake and the exhaust manifolds.
58. Attach the J 41427 to the left front and the right rear intake manifold mounting bolts, using the following procedure: 52.1. Remove the right rear lower intake manifold bolts. 52.2. Install the J 41427 marked RIGHT REAR. 52.3. Install the retaining bolts. 52.4. Remove the left front lower intake manifold bolts. 52.5. Install the J 41427 marked LEFT FRONT with the arrow pointing to the front of the engine. 52.6. Install the retaining bolts. Tighten Tighten the retaining bolts to 15 N.m (11 lb ft).
59. Install a engine lifting device to the engine lift brackets.
60. Remove the engine.

Note. If the engine is damaged internally and a new engine assembly is installed in the vehicle, ensure that all foreign material is flushed out of the cooling system. You must also flush out the oil cooler system. Failure to rid the oil cooler system of debris can result in engine damage.

Scheme 724

Scheme 725

Scheme 726

Scheme 727

Scheme 728

Scheme 729

Scheme 730

Scheme 731

Scheme 732

Scheme 733

Scheme 734

Scheme 735

Scheme 736

Scheme 737

Scheme 738

Scheme 739

Scheme 740

Scheme 741

Scheme 742

1. Attach the J 41427 to the left front and the right rear intake manifold mounting bolts, using the following procedure: 1.1. Remove the right rear lower intake manifold bolts. 1.2. Install the J 41427 marked RIGHT REAR. 1.3. Install the retaining bolts. 1.4. Remove the left front lower intake manifold bolts. 1.5. Install the J 41427 marked LEFT FRONT with the arrow pointing to the front of the engine. 1.6. Install the retaining bolts. Tighten Tighten the retaining bolts to 15 N.m (11 lb ft).
2. Install a engine lifting device to the engine lift brackets.
3. Install the engine into the vehicle.
4. Install the engine mount through-bolts and nuts. Tighten Tighten the engine mount through-bolts or the nuts to the following: Tighten the through-bolts to 74 N.m (55 lb ft) Tighten the nuts to 63 N.m (46 lb ft)
5. Remove the J 41427 and the engine lifting device.
6. Apply thread lock GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the threads of the lower intake manifold bolts.
7. Install the intake manifold bolts. Tighten 7.1. Tighten the bolts the first pass to 3 N.m (27 lb in). 7.2. Tighten the bolts the second pass to 12 N.m (106 lb in). 7.3. Tighten the bolts the third pass to 15 N.m (11 lb ft).
8. Install the EGR valve inlet pipe to the intake manifold and the exhaust manifold. 8.1. Tighten the EGR valve inlet pipe intake manifold nut to 25 N.m (18 lb. ft.). 8.2. Tighten the EGR valve inlet pipe exhaust manifold nut to 30 N.m (22 lb. ft.). 8.3. Tighten the EGR valve inlet pipe clamp bolt 25 N.m (18 lb. ft.).
9. Install the spark plug wire harness retainer on the EGR valve inlet pipe.
10. Install the water outlet.
11. Connect the fuel pipes at the rear of the engine.
12. Install the distributor cap.
13. Connect the EVAP canister purge solenoid valve pipe.
14. Install both of the AIR reactor pipes to the engine.
15. Install the AIR shut-off valve and hoses.
16. Install the power steering pump mounting bracket. Slide the power steering pump mounting bracket on the stud. Position the power steering pump rear bracket on the studs. Install the power steering pump mounting bracket three bolts and the nut. Install the nut for the power steering pump rear bracket to the front of the engine. Tighten Tighten the power steering pump mounting bracket and the power steering pump rear bracket bolts and the nuts to 41 N.m (30 lb. ft.).
17. Install the nut holding the AIR reactor pipe bracket, if equipped to the stud on the front of the engine. Tighten Tighten the bolt to 41 N.m (30 lb. ft.).
18. Install the A/C compressor, if equipped.
19. Install the water pump pulley.
20. Install the accelerator control cable bracket to the throttle body. Tighten Tighten the bolt to 9 N.m (80 lb in).
21. Install the bolt holding the ground wires to the left cylinder head. Tighten Tighten the ground wire bolt to 35 N.m (26 lb ft).
22. Install the bolt holding the fuel pipe bracket to the rear of the left cylinder head. Tighten Tighten the fuel pipe bracket bolt to 30 N.m (22 lb ft).
23. Install the stud holding the ground wires to the right cylinder head. Tighten Tighten the ground wire stud to 35 N.m (26 lb ft).
24. Install the bolt and the ground strap to the rear of the right cylinder head. Tighten Tighten the ground strap bolt to 35 N.m (26 lb ft).
25. Position the engine wiring harness.
26. Install the engine wiring harness clips to the brackets.
27. Install the engine wiring harness clips to the front of the engine.
28. Connect the CKP sensor electrical connector (2).
29. Install the bolt and the battery negative cable (1). Tighten Tighten the bolt to 17 N.m (13 lb ft).
30. Install the engine wiring harness bracket bolt (3) to the generator mounting bracket. Tighten Tighten the stud to 25 N.m (18 lb ft).
31. Install the generator.
32. Connect the following electrical connectors: The distributor (1) The engine oil pressure sensor (2) The knock sensor (3)
33. Connect the following electrical connectors: The A/C compressor clutch (1), if equipped The A/C compressor cutoff switch (5), if equipped The TP sensor (2) The IAC valve motor (3) The ECT sensor (4)
34. Connect the following electrical connectors: The fuel meter body (1) The EVAP canister purge solenoid (2) The MAP sensor (3)
35. Connect the following electrical connectors: The ICM (1) The ignition coil (2) The EGR solenoid (3) The generator (4)
36. Connect the power brake booster vacuum hose to the intake manifold.
37. Connect the vacuum hose for the A/C system, if equipped.
38. Install the cruise control cable, if equipped to the throttle shaft and the accelerator cable bracket. CAUTION: In order to avoid possible injury or vehicle damage, always replace the accelerator control cable with a NEW cable whenever you remove the engine from the vehicle. In order to avoid cruise control cable damage, position the cable out of the way while you remove or install the engine. Do not pry or lean against the cruise control cable and do not kink the cable. You must replace a damaged cable.
39. Install the NEW accelerator cable onto the throttle body.
40. Wrap the cable in between the finger of the hook tab and the pulley wall. Make sure that the cable is fully seated in the pulley groove. The cable must not lie outside of the hook tab.
41. Install the accelerator cable to the accelerator cable control bracket.
42. Install the radiator.
43. Install the inlet and outlet radiator hoses to the engine.
44. Connect the heater hoses to the engine.
45. Raise the vehicle.
46. Install the transmission. Refer to TRANSMISSION for Automatic Transmission - 4L60-E. Refer to TRANSMISSION REPLACEMENT for Manual Transmission - NV 3500.
47. Install the transmission cover. Tighten Tighten the nut to 12 N.m (106 lb in).
48. Install the starter. Refer to appropriate STARTER article.
49. Install the stud holding the bracket for the starter wiring harness and if equipped, the transmission oil cooler lines. Tighten Tighten the bracket stud to 9 N.m (80 lb in).
50. Install the engine oil cooler pipes.
51. Install the exhaust pipe to the exhaust manifolds.
52. Install a NEW oil filter. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
53. Add engine oil supplement GM P/N 1052367 (Canadian P/N 992869) or equivalent to the engine oil.
54. Install the underbody shields, if equipped.
55. Lower the vehicle.
56. Fill the engine with oil. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/blazer/s15-1998-2005/remont/mechanical/#engine-mechanical-43l) .
57. Fill the cooling system.
58. Connect the negative battery cable. NOTE: Handle the MAF sensor carefully. Do not drop the MAF sensor in order to prevent damage to the MAF sensor. Do not damage the screen located on the air inlet end of the MAF. Do not touch the sensing elements. Do not allow solvents and lubricants to come in contact with the sensing elements. Use a small amount of a soap based solution in order to aid in the installation.
59. Install air cleaner outlet duct to throttle body.
60. Install air cleaner outlet duct to MAF sensor. Tighten Tighten the hose clamp to 4 N.m (32 lb in).
61. Connect the intake air temperature (IAT) sensor harness connector.
62. Install the air cleaner outlet duct retaining wing nut. Tighten Tighten the wingnut to 2 N.m (18 lb in).
63. Install the breather tube to the air cleaner outlet duct.
64. Install the PCV tube to the right valve rocker arm cover and the air cleaner outlet duct.
65. Recharge the air conditioning system, if equipped.
66. Install the hood.
67. With the ignition OFF or disconnected, crank the engine several times. Listen for any unusual noises or evidence that any of the parts are binding.
68. Start the engine and listen for unusual noises.
69. Check the vehicle oil pressure gauge or light and confirm that the engine has acceptable oil pressure. If necessary, install an oil pressure gauge and measure the engine oil pressure.
70. Operate the engine at about 1,000 RPM until the engine has reached normal operating temperature.
71. Listen for improperly adjusted or sticking valves, sticking valve lifters, or other unusual noises.
72. Inspect for oil and/or coolant leaks while the engine is operating.
73. Verify that the distributor is properly positioned.
74. Perform a final inspection for the proper engine oil and coolant levels.

Scheme 743

Scheme 744

Scheme 745

1. Raise and support the vehicle.
2. Remove the oil pan drain plug and drain the engine oil into a suitable container.
3. For 2WD vehicles, remove the oil filter from the oil filter adapter.
4. For Four-Wheel Drive vehicles, open the access panel in the steering linkage shield.
5. Remove the oil filter from the remote oil filter adapter.
6. Inspect to ensure the engine oil filter gasket is removed.

Scheme 746

Scheme 747

Scheme 748

1. Lubricate the oil filter gasket with clean engine oil.
2. For a RWD vehicle, install the oil filter to the oil filter adapter.
3. For Four-Wheel Drive vehicles, install the oil filter to the remote oil filter adapter.
4. Tighten the oil filter following the instructions on the filter.
5. Install the oil pan drain plug into the oil pan Tighten Tighten the oil pan drain plug to 25 N.m (18 lb ft).
6. Lower the vehicle.
7. Fill the crankcase with the proper capacity and quality of engine oil.
8. Operate the engine and check for leaks and oil pressure.
9. For a Four-Wheel Drive vehicles, close the access panel in the steering linkage shield.

Scheme 749

A crankcase ventilation system is used in order to provide a more complete scavenging of crankcase vapors. The air cleaner supplies fresh air through a filter to the crankcase. The crankcase mixes the fresh air with blow-by gases. This mixture then passes through a crankcase ventilation valve into the intake manifold.

The primary control is through the crankcase ventilation valve (1), which meters the flow at a rate depending on the manifold vacuum.

In order to maintain an idle quality, the crankcase ventilation valve restricts the flow when the intake manifold vacuum is high. If abnormal operating conditions arise, the system is designed in order to allow the excessive amounts of blow-by gases to back flow through the crankcase vent tube into the air cleaner in order 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.

Tools and Equipment

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

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

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

Scheme 750

Scheme 751

Scheme 752

Scheme 753

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

Scheme 754

Scheme 755

Scheme 756

Scheme 757

See also:
• DISASSEMBLED VIEWS
• NEW PRODUCT INFORMATION
• CAMSHAFT & BEARINGS CLEANING & INSPECTION
• EXHAUST MANIFOLD REMOVAL - LEFT
• CYLINDER HEAD DISASSEMBLE
• CYLINDER HEAD CLEANING & INSPECTION
• VALVE GUIDE REAMING/VALVE & SEAT GRINDING
• CYLINDER HEAD ASSEMBLE
• EXHAUST MANIFOLD REMOVAL - RIGHT
• WATER PUMP REMOVAL
• WATER PUMP INSTALLATION
• BALANCE SHAFT CLEANING & INSPECTION
• BALANCE SHAFT INSTALLATION
• Drive Belt System Description
• Symptoms - Engine Mechanical
• Engine Compression Test
• Oil Consumption Diagnosis
• Oil Pressure Diagnosis and Testing
• Engine Mechanical Specifications