Engine Mechanical - 4.2L: Other GMC Envoy II

Sealers, Adhesives, and Lubricants

Sealers, Adhesives, and Lubricants

Scheme 31

Engine Block - Top View

Scheme 32

Engine Block - Bottom View

Scheme 33

Engine Block - Left Side View

Scheme 34

Engine Block - Right Side View

Scheme 35

Engine Block - Front View

Scheme 36

Engine Block - Rear View

Scheme 37

Cylinder Head - Top View

Scheme 38

Cylinder Head - End View (Front)

Scheme 39

Cylinder Head - End View (Rear)

Scheme 40

Cylinder Head - Intake Manifold Deck View

Scheme 41

Cylinder Head - Exhaust Manifold Deck View

Scheme 42

Oil Pan - Top View

Scheme 43

Oil Pan - Left Side View

Scheme 44

Oil Pan - Right Side View

Scheme 45

Oil Pan - Rear View

Scheme 46

Engine Front Cover

Scheme 47

Crankshaft Rear Oil Seal Housing

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

Scheme 53

Scheme 54

Scheme 55

Intermittent

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

Base Engine Misfire without Internal Engine Noises

Base Engine Misfire without Internal Engine Noises

Base Engine Misfire with Abnormal Internal Lower Engine Noises

Base Engine Misfire with Abnormal Internal Lower Engine Noises

Base Engine Misfire with Coolant Consumption

Base Engine Misfire with Coolant Consumption

Base Engine Misfire with Excessive Oil Consumption

Base Engine Misfire with Excessive Oil Consumption

Engine Will Not Crank - Crankshaft Will Not Rotate

Engine Will Not Crank - Crankshaft Will Not Rotate

Coolant in Combustion Chamber

Coolant in Combustion Chamber

Coolant in Engine Oil

Coolant in Engine Oil

Tools Required

J 38722 Compression Tester. See Special Tools .

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

1. Remove the air duct from the throttle control module.
2. Remove the ignition control modules.
3. Disable the fuel system.
4. Remove the spark plugs.
5. Measure the engine compression, using the following procedure: Firmly install J 38722 to the spark plug hole. See «Special Tools»(ref-200396-S26818425802005102000000) . Have an assistant crank the engine through at least four compression strokes in the testing cylinder. Check and record the readings on J 38722 at each stroke. See «Special Tools»(ref-200396-S26818425802005102000000) . Disconnect J 38722 . See «Special Tools»(ref-200396-S26818425802005102000000) . Repeat the compression test for each cylinder.
6. Record the compression readings from all of the cylinders. A normal reading should be approximately 1482 kPa (215 psi). The lowest reading should not be less than 70 percent of the highest reading.
7. The following are examples of the possible measurements: When the compression measurement is normal, the compression builds up quickly and evenly to the specified compression on each cylinder. When the compression is low on the first stroke and tends to build up on the following strokes, but does not reach the normal compression, or if the compression improves considerably with the addition of three squirts of oil, the piston rings may be the cause. When the compression is low on the first stroke and does not build up in the following strokes, or the addition of oil does not affect the compression, the valves may be the cause. When the compression is low on two adjacent cylinders, or coolant is present in the crankcase, the head gasket may be the cause.
8. Install the air duct to the throttle body.
9. Install the spark plugs.
10. Enable the fuel system.
11. Install the ignition control modules.

J 35667-A Cylinder Head Leakdown Tester. See Special Tools .

1. Disconnect the battery ground negative cable.
2. Remove the spark plugs. Refer to «Spark Plug Replacement»(ref-200372-S40778924732005102000000) in Engine Control.
3. Rotate the crankshaft to place the piston in the cylinder being tested at Top Dead Center (TDC) of the compression stroke.
4. Install J 35667-A . See «Special Tools»(ref-200396-S26818425802005102000000) .
5. Apply shop air pressure to J 35667-A and adjust according to the manufacturers instructions. See «Special Tools»(ref-200396-S26818425802005102000000) .
6. Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions: Air leakage sounds at the throttle control module or air inlet hose may indicate a worn or burnt intake valve or a broken valve spring. Air leakage sounds at the exhaust system tailpipe may indicate a worn or burnt exhaust valve or a broken valve spring. Air leakage sounds from the crankcase, oil level indicator tube, or oil fill tube may indicate worn piston rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block or a damaged cylinder head. Air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket.
7. Perform the leakage test on the remaining cylinders and record the values.

Front Engine Mount

1. Install a pole jack underneath the oil pan.
2. Insert a block of wood between the engine oil pan and the pole jack.
3. Raise the jack until the wooden block contacts the engine oil pan.
4. Raise the engine in order to place a slight tension on the rubber cushion. Observe both mounts while raising the engine.
5. Replace the mounts if any of the following conditions exist: Hard rubber surface covered with heat check cracks The rubber cushion separated from the metal plate of the mount The rubber cushion is split through the center The mount is leaking
6. If there is movement between a metal plate of the mount and its attaching points, lower the engine and tighten the bolts or nuts attaching the mount to the engine, the frame or the bracket.

J 36660-A Torque Angle Meter

J 44218 Seal Installer. See Special Tools .

J 44219 Cover Alignment Pins. See Special Tools .

J 44227 Rear Seal Installer. See Special Tools .

J 36660-A Torque Angle Meter

J 44220 Engine Lift Bracket. See Special Tools .

Tool Required

J 41240 Fan Clutch Remover and Installer. See Special Tools .

1. Install J 41240 to hold the pulley. See «Special Tools»(ref-200396-S26818425802005102000000) .
2. Remove the water pump pulley bolts.
3. Remove J 41240 . See «Special Tools»(ref-200396-S26818425802005102000000) .
4. Remove the water pump pulley
5. Remove the water pump bolts.
6. Remove the water pump.
7. Remove the water pump gasket.

J 41816-2 Crankshaft End Protector. See Special Tools .

1. Remove the crankshaft balancer bolt.
2. Install J 41816-2 into the end of the crankshaft. See «Special Tools»(ref-200396-S26818425802005102000000) .
3. Use a three jaw puller to remove the crankshaft balancer.
4. Remove J 41816-2 . See «Special Tools»(ref-200396-S26818425802005102000000) .

J 41556 Connecting Rod Guides. See Special Tools .

1. Mark the piston with the number of the cylinder from which the piston is being removed.
2. Mark the connecting rod and the connecting rod cap with the cylinder position. Also mark the orientation. This will ensure the caps and connecting rods are re-assembled properly.
3. Remove the connecting rod bolts.
4. Remove the connecting rod cap and bearing half.
5. Install J 41556 on the connecting rod. See «Special Tools»(ref-200396-S26818425802005102000000) .
6. Remove the connecting rod and piston assembly. Push out the assembly.
7. Remove J 41556 . See «Special Tools»(ref-200396-S26818425802005102000000) .

Cylinder Honing

1. When honing the cylinder bores, follow the manufacturer's recommendations for equipment use, cleaning, and lubrication. Use only clean sharp stones of the proper grade for the amount of material to be removed. Dull, dirty stones cut unevenly and generate excessive heat. DO NOT hone to a final grade with a coarse or medium-grade stone. Leave sufficient metal so that all the stone marks will be removed with the fine grade stones. Perform the final honing with a fine-grade stone and hone the cylinder bore in a cross hatch pattern at 45-65 degrees to obtain the proper clearance.
2. During the honing operation, thoroughly check the cylinder bore. Repeatedly check the cylinder bore fit with the selected piston. All measurements of the piston or cylinder bore should be made with the components at normal room temperature.
3. When honing to eliminate taper in the cylinder bore, use full strokes the complete length of the cylinder bore. Repeatedly check the measurement at the top, the middle, and the bottom of the cylinder bore. The finish marks should be clean but not sharp. The finish marks should be free from imbedded particles or torn or folded metal.
4. When finished, the reconditioned cylinder bores should have less than or meet the specified out-of-round and taper requirements.
5. After the final honing and before the piston is checked for fit, clean the cylinder bore with hot water and detergent. Scrub the cylinder bores with a stiff bristle brush. Rinse the cylinder bores thoroughly with clean hot water. Dry the cylinder bores with a clean rag. Do not allow any abrasive material to remain in the cylinder bores. Abrasive material may cause premature wear of the new piston rings and the cylinder bores. Abrasive material will contaminate the engine oil and may cause premature wear of the bearings.
6. Perform final measurements of the piston and the cylinder bore.
7. Permanently mark the top of the piston for the specified cylinder to which it has been fitted.
8. Apply clean engine oil to each cylinder bore in order to prevent rusting.

J 43654 Piston Pin Retainer Clip Remover/Installer. See Special Tools .

1. Remove the piston rings using a piston ring expander.
2. Remove the piston pin retaining clips.
3. Remove the piston pin.

J 8087 Cylinder Bore Gage. See Special Tools .

1. Clean and soak the following components in a carburetor cleaning solution to remove carbon, sludge, and varnish: Piston Piston pin Connecting rod
2. Install the connecting rod cap.
3. Place the connecting rod assembly on a checking fixture.
4. Inspect the connecting rod assembly for bending or twisting.
5. Replace any bent or twisted connecting rods.
6. If the connecting rod large bore contains minor scratches or abrasions, clean the bore in a circular direction with light emery paper. DO NOT scrape the connecting rod or cap.
7. Measure the piston pin to connecting rod bore using the following procedure: Using an outside micrometer, take two measurements of the piston pin in the area of the connecting rod contact. Using an inside micrometer, measure the connecting rod piston pin bore. Subtract the piston pin diameter from the piston pin bore diameter. The clearance should not be more than 0.018 mm (0.0007 in).
8. If there is excessive clearance, replace the piston pin.
9. If there is still excessive clearance, replace the connecting rod.
10. If there is evidence of pin bore or pin scoring, replace the rod and pin assembly.
11. Inspect the connecting rod bearings for the following conditions: Craters or pockets Flattened sections Excessive scoring or discoloration. Imbedded debris bright, polished sections
12. Inspect the inside of the connecting rod bearing and outside diameter of the connecting rod bearing journal for wear. This indicates high spots.
13. Inspect the connecting rod bearing bore for taper and out-of-round.
14. Inspect the connecting rod bolts for stretching (compare to new or known good bolt). (1) is a stretched bolt, (2) is a new or good bolt.
15. Clean the piston skirts and the pins with a cleaning solvent. DO NOT wire brush any part of the piston.
16. Clean the piston ring grooves. Ensure that the oil ring holes and slots are clean.
17. Inspect the pistons for the following conditions: Cracked ring lands, skirts, or pin bosses Ring grooves for nicks, burrs that may cause binding Warped or worn ring lands Eroded areas at the top of the piston Scuffed or damaged skirts Worn piston pin bores
18. Replace pistons that show any signs or damage or excessive wear.
19. Measure the piston diameter for size with a micrometer or caliper at a right angle to the pin center line, across the skirts, 38 mm (1.50 in) from the top of the piston.
20. Replace the piston if worn beyond specifications or if damaged.
21. Use J 8087 to measure the cylinder bore. See «Special Tools»(ref-200396-S26818425802005102000000) .
22. Hone to size if necessary. Use the following procedure to hone the cylinder bore to the correct size. Select a piston. Hone the cylinder bore to obtain the recommended clearance. Clean the piston and cylinder bore with soap and water. Dry the cylinder bore and piston. Lubricate the cylinder bore with clean engine oil.
23. Use the following procedure to measure the piston-to-cylinder bore clearance. Subtract the piston diameter from the cylinder bore diameter to determine the piston-to-bore clearance. Compare the piston-to-bore clearance using the specifications to determine if the clearance is in the acceptable range. If the used piston is not acceptable, a new service piston may be selected.
24. When a piston has been selected, mark the piston to identify the cylinder for which the piston was fitted.
25. Select a set of new piston rings.
26. Install each ring, one at a time, into the corresponding cylinder.
27. Install the piston for that cylinder, upside down (top of piston pushing on the ring) and push the ring to approximately 25 mm (1 in) down from the deck surface.
28. Remove the piston.
29. Measure the ring end gap with a feeler gage.
30. If the ring gap is not within the specification range, replace the rings.
31. Measure the piston ring side clearance - compression rings.
32. Use the following procedure to measure the compression ring side clearance. Roll the piston ring around the groove. Measure the side clearance with a feeler gage. If the ring is too tight, inspect the piston ring groove for nicks, burrs, or damage. Use emery cloth to remove any minor burrs. If the ring side clearance is greater than the specification, replace the piston.

EN-45680-400 Cylinder Sleeve Removal and Installation Kit. See Special Tools .

1. If the crankshaft is still installed, rotate the crankshaft so that the counterweight is to the right side and the connecting rod journal is to the left side and not in alignment with the cylinder bore.
2. Install the cylinder bore sleeve puller EN 45680-402 (1) which is part of EN-45680-400 , through the cylinder bore. See «Special Tools»(ref-200396-S26818425802005102000000) .
3. Align the shoe (1) of the cylinder bore sleeve puller EN 45680-402 to the bottom of the cylinder bore sleeve (117).
4. Hold the threaded shaft of the cylinder bore sleeve puller EN 45680-402 upward in order to retain the shoe alignment to the bottom of the cylinder bore sleeve.
5. Install the fixture EN 456850-401 (4) onto the threaded shaft of the cylinder bore sleeve puller EN 456850-402 and the engine block.
6. Install the bearing (3) and the nut (1).
7. Tighten the nut (1) to the bearing (3).
8. Install and tighten the 4 attaching bolts (2) into the cylinder head bolt holes of the block. Tighten: Tighten the bolts to 15 N.m (11 lb ft).
9. Rotate the nut clockwise in order to remove the cylinder bore sleeve.
10. Remove fixture EN 45680-401, cylinder bore sleeve puller EN 45680-402, and the cylinder bore sleeve (117) from the engine block.
11. Loosen the nut (1) in order to remove the cylinder bore sleeve (117).
12. Inspect the cylinder bore in the cylinder block for cracks or damage. If cracked or damaged, replace the cylinder block.
13. Inspect the piston, piston rings, and connecting rod for damage. Refer to «Piston, Connecting Rod, and Bearings Cleaning and Inspection»(ref-200396-S08374110392005102000000) .

EN-45680-400 Cylinder Sleeve Removal and Installation Kit. See Special Tools .

1. Place the NEW cylinder bore sleeve (117) onto the cylinder block.
2. Install fixture EN 45680-401/cylinder bore sleeve installer EN 45680-403 assembly (1) which is part of EN-45680-400 , over the cylinder bore sleeve (117) and onto the cylinder block. See «Special Tools»(ref-200396-S26818425802005102000000) . Do not apply downward pressure to the cylinder bore sleeve (117).
3. Insert the 4 attachment bolts into the legs of the fixture EN 45680-401 (1).
4. Tighten the 4 attachment bolts. Do not apply downward pressure to the cylinder bore sleeve (117). Tighten: Tighten the 4 attachment bolts to 15 N.m (11 lb ft).
5. Align the bottom of the cylinder bore sleeve (117) with the cylinder bore of the block (100).
6. Align the installation arbor (1) onto the top of the cylinder bore sleeve (117).
7. Align the pusher block (2) of cylinder bore sleeve installer EN 45680-403 into the groove of fixture EN 45680-401 (1).
8. Using a ratchet, rotate the threaded shaft of fixture EN 45680-401/cylinder bore sleeve installer EN 45680-403 assembly (1) in order to install the cylinder bore sleeve (117) into the engine block (100).
9. Do not completely seat the cylinder bore sleeve in the block. Leave approximately 1/16 inch of the cylinder bore sleeve above the surface of the cylinder block.
10. Using a torque wrench, torque the threaded shaft of the fixture EN 45680-401/cylinder bore sleeve installer EN 45680-403 assembly to 102 N.m (75 lb ft) in order to completely seat the cylinder bore sleeve in the cylinder block. With the cylinder bore sleeve properly installed, a minimal portion of the cylinder bore sleeve flange will protrude above the block deck surface.
11. Remove the fixture EN 45680-401/cylinder bore sleeve installer EN 45680-403 assembly (1) from the cylinder block (100).

Scheme 56

1. EN 45680-865 Debris Collector (3)
2. EN 45680-411 Trim Tool Assembly (2)
3. Air Control Valve (1 - Part of EN 45680-411
4. Drill Motor with 1/2 inch chuck, 1 1/8 hp, 7 amps, triple gear reduction, and a 450-600 RPM rotational speed in a clockwise direction

Scheme 57

1. Trim Tool Preloader (1)
2. EN 45680-412 Set Gage Ring (2)
3. EN 45680-413 Metal Shavings Catch Plug (3)
4. EN 45680-866 Drive Adapter (4)
5. EN 45680-414 Bolts (5)

1. After installing the NEW cylinder bore sleeve(s) into the engine block, trim the excess material from the cylinder bore sleeve flange.
2. Place metal shaving catch plug EN 45680-413 into the cylinder bore sleeve to be trimmed. Position the top of the EN 45680-413 approximately 3.0 mm (0.12 in) below the top surface of the cylinder bore sleeve.
3. Place additional metal shaving catch plugs EN 45680-413 into all remaining cylinder bore sleeves.
4. Ensure that the metal shaving catch plug EN 45680-413 is 3.0 mm (0.12 in) below the top surface of the cylinder bore sleeve.
5. The groove side of the set gage ring EN 45680-412 (1) should be positioned upward on a flat surface.
6. Carefully position trim tool assembly EN 45680-411 onto the set gage ring EN 45680-412.
7. Loosen the shaft collar screw (2).
8. Push the shaft collar (2) downward using the trim tool preloader (1) until the shaft collar is positioned against the top of the flange bearing (3).
9. Apply downward pressure on the collar and inner drive shaft using the trim tool preloader (1), then tighten the shaft collar screw. Tighten: Tighten the shaft collar screw to 19 N.m (14 lb ft).
10. Place trim tool assembly EN 45680-411 onto the cylinder to be trimmed with the directional arrow (1) pointing in line with the crankshaft centerline and the front of the block.
11. Install the 4 bolts EN 45680-414 (2) into the cylinder head bolt holes in the block. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
12. Fasten drive adapter EN 45680-866 (1) into the drill chuck.
13. Connect a compressed air supply (75-125 psi) to the male quick connect (3) located on trim tool assembly EN 45680-411. Turn the compressed air valve (2) to the open position. This starts the venturi vacuum system that will catch the metal shavings.
14. Place drive adapter EN 45680-866 and drill assembly (1) vertically onto the drive adapter end of trim tool assembly EN 45680-411. Do not apply downward force on the drill until full rotational speed has been reached. After reaching full rotational speed, gradually apply downward force until the cutting action is complete in approximately 5 seconds.
15. Remove drive adapter EN 45680-866 (1) and drill assembly from the trim tool assembly EN 45680-411.
16. Turn off the compressed air valve (2).
17. Remove trim tool assembly EN 45680-411 from the engine block.
18. Remove any material shavings that may be found on the metal shaving catch plug EN 45680-413.
19. Wipe the cylinder bore sleeve and surrounding areas free of any powder residue and then remove the metal shaving catch plug EN 45680-413.
20. Install a straight edge on the cylinder block perpendicular to the crankshaft center line.
21. Using a light, illuminate the backside of the straight edge.
22. Looking at the front of the straight edge, check to see if light is protruding through the bottom of the straight edge and the top of the cylinder bore sleeve flange. If light is present of either side or both sides of the cylinder bore sleeve, the cylinder bore sleeve is cut incorrectly and a new cylinder bore sleeve needs to be installed.
23. Looking at the front of the straight edge, check to see if light is protruding through the bottom of the straight edge and the top of the cylinder block deck surface. If light is present on both sides of the cylinder block, the cylinder bore sleeve is cut correctly.
24. Proceed to the next bore sleeve to be trimmed repeating steps 10-23 if necessary.

J 43654 Piston Pin Retainer Remover/Installer. See Special Tools .

1. Lubricate the piston pin with clean engine oil.
2. Install one of the piston pin retainers into the retainer groove.
3. Install the connecting rod and piston pin. Push the piston pin in until it bottoms against the installed piston pin retainer.
4. Install the second piston pin retainer.
5. Install the following components of the bottom ring assembly (oil control ring). The expander The lower oil control ring The upper oil control ring
6. Install the middle ring (compression ring) with the napier groove facing down.
7. Install the top ring.

J 7872 Magnetic Base Dial Indicator Set

1. Clean the camshafts with cleaning solvent.
2. Inspect the camshafts for the following conditions: Scored camshaft journals Damaged camshaft lobes Damaged camshaft sprocket locator pin slots Damaged threads
3. Measure the camshaft lobes using a micrometer. The intake camshaft lobes should be a minimum of 41.5 mm (1.635 in). The exhaust camshaft lobes should be a minimum of 41 mm (1.615 in).
4. Use J 7872 to measure the camshaft runout. Set the camshaft in V-blocks between the centers. Measure the intermediate camshaft journal.
5. Use J 7872 to measure the camshaft lobe lift. Lubricate the camshaft to V-block contact areas with engine oil. Set the camshaft on V-blocks. Measure the camshaft lobe lift.
6. If the runout or camshaft lobe lift is not within specifications, replace the camshaft.

J 9666 Valve Spring Tester

1. Inspect the cylinder head gasket and the mating surface. Inspect for leaks, corrosion, and blowby.
2. If the gasket failed, determine the cause. The following conditions may cause gasket failure: Improper installation Warped cylinder head Missing or not fully seated dowel pins Low torque on the cylinder head bolts Incorrect length cylinder head bolts A warped engine block surface Scratched surfaces Foreign material Cracked engine block threaded holes
3. Clean the following components: The gasket surfaces Do not use a motorized brush on the head gasket sealing surface. Valve stems and valve heads The bolt hole threads Remove all dirt, debris, or threadlocking material from the bolt holes.
4. Inspect the cylinder head mating surfaces for flatness. Use a feeler gauge and a straight edge.
5. Replace the cylinder head if warped more than 0.08 mm (0.003 in).
6. Inspect the cylinder head for cracks.
7. Inspect the cylinder head deck for corrosion.
8. Inspect the valve springs for squareness.
9. Use J 9666 to measure the valve spring tension. Replace the valve spring if the tension is not within specification.
10. Inspect the valve guides for wear. The valve guides may be reamed oversized 0.075 mm (0.003 in) and oversized stemmed valves may be installed. The same size valve seal should be used.
11. Inspect the valve seats for excessive wear, damage, or hot spots.
12. Use the following procedure to measure the valve seat concentricity: Lift the valve off the valve seat. Apply a dab of blue dye to the valve face. Seat and rotate the valve. The blue dye traces transferred to the valve seat are an indication of concentricity of the valve seat.
13. Use the following procedure to measure the valve runout: Clean off the blue dye. Apply blue dye to the valve seat. Seat and rotate the valve. The traces of blue dye transferred to the valve indicates valve runout.
14. Replace the head if the valve seats are damaged.
15. Inspect the valves for the following damage: Grooving (1, 2) Bent valve stem (3). Replace any bent valve. Burrs or scratches (4). Minor burrs or scratches may be removed with a fine oil stone. Chipped or worn key grooves (5). Replace if damaged. Valve tip wear (6). Replace if worn.

Thread Repair

Tools Required

1. J 42385-400 Thread Repair Kit. See «Special Tools»(ref-200396-S26818425802005102000000) .
2. J 43965 Extension Kit. See «Special Tools»(ref-200396-S26818425802005102000000) .

The thread repair process involves a solid, thin walled, self-locking, carbon steel, bushing type insert. During the insert installation process, the installation driver tool cold-rolls the bottom internal threads and expands the bottom external threads of the insert into the base material. This action mechanically locks the insert into place.

Scheme 58

The tool kit J 42385-400 is designed for use with either a suitable tap wrench or drill motor. See Special Tools . Limited access and larger hole repair may process better using a tap wrench. An extension J 43965 may also be necessary to drive the thread repair tooling dependent on access to the hole being repaired. See Special Tools .

Scheme 59

It is critical that the drilling, counterboring and tapping of the hole to be repaired follows the same centerline as the original hole.

Scheme 60

During the drilling and tapping of the hole being repaired ensure the tooling is consistently machining perpendicular to the surface of the base material.

Scheme 61

If the threaded hole being repaired has a base surface perpendicular to the hole centerline, tapping guides are available to aid in tapping the hole.

Thread Repair

Scheme 62

When installed to the proper depth, the flange (1) of the insert will be seated against the counterbore of the drilled/tapped hole and just below the surface (2) of the base material.

1. Drill out the threads of the damaged hole. M6 inserts require a minimum drill depth of 15 mm (0.59 in). M8 inserts require a minimum drill depth of 20 mm (0.79 in). M10 inserts require a minimum drill depth of 23.5 mm (0.93 in).
2. Using compressed air, clean out any chips.
3. Counterbore the drilled hole to the full depth permitted by the tool (1).
4. Using compressed air, clean out any chips.
5. Using a suitable tapping wrench, tap the threads of the drilled hole. M6 inserts require a minimum tap depth of 15 mm (0.59 in). M8 inserts require a minimum tap depth of 20 mm (0.79 in). M10 inserts require a minimum tap depth of 23.5 mm (0.93 in).
6. Using compressed air, clean out any chips.
7. Spray cleaner GM P/N United States 12377981, GM P/N Canada 10953463 or equivalent into the tapped hole.
8. Using compressed air, clean out any chips.
9. Lubricate the threads of the driver installation tool (2) with the driver oil (1) J 42385-110.
10. Install the insert (2) onto the driver installation tool (1).
11. Apply threadlock sealant GM P/N United States 12345493, GM P/N Canada 10953488, J 42385-109, LOCTITE 277® or equivalent (1) to the insert OD threads (2).
12. Install the insert (2) into the tapped hole.
13. Install the insert until the flange (2) of the insert contacts the counterbored surface.
14. Continue to rotate the driver installation tool (1) through the insert (2).
15. Inspect the insert for proper installation into the tapped hole. A properly installed insert (1) will be either flush or slightly below flush with the surface of the base material (2).
16. Any installed insert that restricts or blocks an oil or engine coolant passage (3) will need to have the oil or engine coolant passage drilled out (4) to the original size of the oil or engine coolant passage. After drilling the restriction or blockage, clean out any chips and thread the installation driver tool through the insert again to remove any burrs caused by the drilling of the oil or engine coolant passage.

Scheme 63

When installed to the proper depth, the flange of the insert (1) will be seated against the counterbore (2) of the drilled/tapped hole.

1. Install a stop collar (2) on the counterbore drill (1), if required.
2. Drill out the threads of the damaged hole.
3. Using compressed air, clean out any chips.
4. Using a suitable tapping wrench, tap the threads of the drilled hole.
5. Using compressed air, clean out any chips.
6. Spray cleaner GM P/N United States 12377981, GM P/N Canada 10953463 or equivalent into the tapped hole.
7. Using compressed air, clean out any chips.
8. Lubricate the threads of the driver installation tool (2) with the driver oil (1) J 42385-110.
9. Install the insert (2) onto the driver installation tool (1).
10. Apply threadlock sealant GM P/N United States 12345493, GM P/N Canada 10953488, J 42385-109, LOCTITE 277® or equivalent (1) to the insert OD threads (2).
11. Install the insert (2) into the tapped hole.
12. Install the insert until the flange (2) of the insert contacts the counterbored surface.
13. Continue to rotate the driver installation tool (1) through the insert (2).
14. Inspect the insert (1) for proper installation (2) into the tapped hole.
15. Any installed insert that restricts or blocks an oil or engine coolant passage (3) will need to have the oil or engine coolant passage drilled out (4) to the original size of the oil or engine coolant passage. After drilling the restriction or blockage, clean out any chips and thread the installation driver tool through the insert again to remove any burrs caused by the drilling of the oil or engine coolant passage.

Tapered Pipe Thread Repair

The thread repair insert for tapered pipe threads is coated with a clear silver zinc coating.

Scheme 64

When installed to the proper depth, the flange (1) of the insert will be seated against surface (2) of the base material of the drilled/tapped hole.

1. Drill out the threads of the damaged hole.
2. Using compressed air, clean out any chips.
3. Using a suitable tapping wrench, tap the threads of the drilled hole.
4. Tap the drilled hole until the threads at the top of the tap (2) are down to the surface of the base material.
5. Using compressed air, clean out any chips.
6. Spray cleaner GM P/N United States 12377981, GM P/N Canada 10953463 or equivalent into the tapped hole.
7. Using compressed air, clean out any chips.
8. Lubricate the threads of the driver installation tool (2) with the driver oil (1) J 42385-110.
9. Install the insert (2) onto the driver installation tool (1).
10. Apply threadlock sealant GM P/N United States 12345493, GM P/N Canada 10953488, J 42385-109, LOCTITE 277® or equivalent (1) to the insert OD threads (2).
11. Install the insert (2) into the tapped hole.
12. Install the insert until the flange (2) of the insert contacts the surface of the base material.
13. Continue to rotate the driver installation tool (1) until the top of the threaded section (2) is level with the top of the insert (3).
14. Inspect the insert (1) for proper installation (2) into the tapped hole.
15. Any installed insert that restricts or blocks an oil or engine coolant passage (3) will need to have the oil or engine coolant passage drilled out (4) to the original size of the oil or engine coolant passage. After drilling the restriction or blockage, clean out any chips and thread the installation driver tool through the insert again to remove any burrs caused by the drilling of the oil or engine coolant passage.

Scheme 65

The cylinder head bolt hole required tools consist of the following

1. Drill (1) J 42385-402
2. Tap (2) J 42385-403
3. Installation driver (3) J 42385-404
4. Alignment pin (4) J 42385-303
5. Bushing (5) J 42385-302
6. Bolts (6) J 42385-421
7. Fixture plate (7) J 42385-401

When installed to the proper depth, the flange of the insert will be seated against the counterbore of the drilled/tapped hole.

1. Position the fixture plate (3) with the bushing (1) installed over the cylinder head bolt hole to be repaired (4).
2. Loosely install the fixture plate bolts (2) into the remaining cylinder head bolt holes.
3. Position the alignment pin (1) through the bushing and into the cylinder head bolt hole.
4. With the alignment pin in the desired cylinder head bolt hole, tighten the fixture retaining bolts (2).
5. Remove the alignment pin (1) from the cylinder head bolt hole.
6. Drill out the threads of the damaged hole.
7. Using compressed air, clean out any chips.
8. Using a suitable tapping wrench, tap the threads of the drilled hole.
9. In order to tap the new threads for the insert to the proper depth, rotate the tap into the cylinder head bolt hole until the first mark (1) on the tap aligns with the top of the drill bushing (3).
10. Remove the fixture plate bolts (2).
11. Remove the fixture plate (3) and bushing (1).
12. Using compressed air, clean out any chips.
13. Spray cleaner GM P/N United States 12377981, GM P/N Canada 10953463 or equivalent into the tapped hole.
14. Using compressed air, clean out any chips.
15. Lubricate the threads of the driver installation tool (2) with the driver oil (1) J 42385-110.
16. Install the insert (2) onto the driver installation tool (1).
17. Apply threadlock sealant GM P/N United States 12345493, GM P/N Canada 10953488, J 42385-109, LOCTITE 277®, or equivalent (1) to the insert OD threads (2).
18. Install the insert and installation driver (1) into the tapped hole.
19. Start the insert into the threaded hole.
20. Install the insert until the flange of the insert contacts the counterbored surface.
21. Continue to rotate the driver installation tool through the insert.
22. Inspect the insert for proper installation into the tapped hole.

Scheme 66

The crankshaft main bearing bolt hole required tools consist of the following

1. Drill (1) J 42385-417
2. Tap (2) J 42385-418
3. Installation driver (3) J 42385-419
4. Fixture plate (4) J 42385-401
5. Bushing (5) J 42385-307
6. Alignment pin (6) J 42385-308
7. Bolts (7) J 42385-510

When installed to the proper depth, the flange of the insert will be seated against the counterbore of the drilled/tapped hole.

1. Position the fixture plate (3) with the bushing (2), installed over the crankshaft main cap bolt hole to be repaired.
2. Loosely install the fixture plate bolts (1) into the remaining crankshaft main cap bolt holes.
3. Position the alignment pin (1) through the bushing and into the crankshaft main cap bolt hole.
4. With the alignment pin in the desired crankshaft main cap bolt hole, tighten the fixture retaining bolts (2).
5. Remove the alignment pin (1) from the crankshaft main cap bolt hole.
6. Drill out the threads of the damaged hole.
7. Using compressed air, clean out any chips.
8. Using a suitable tapping wrench, tap the threads of the drilled hole.
9. In order to tap the new threads for the insert to the proper depth, rotate the tap into the crankshaft main cap bolt hole until the mark (3) on the tap aligns with the top of the drill bushing (2).
10. Using compressed air, clean out any chips.
11. Spray cleaner GM P/N United States 12377981, GM P/N Canada 10953463 or equivalent into the tapped hole.
12. Using compressed air, clean out any chips.
13. Lubricate the threads of the driver installation tool (2) with the driver oil (1) J 42385-110.
14. Install the insert (2) onto the driver installation tool (1).
15. Apply threadlock sealant GM P/N United States 12345493, GM P/N Canada 10953488, J 42385-109, LOCTITE 277® or equivalent (1) to the insert OD threads (2).
16. Install the insert and installation driver (1) into the tapped hole.
17. Start the insert into the threaded hole.
18. Install the insert until the flange of the insert contacts the counterbored surface.
19. Continue to rotate the driver installation tool through the insert.
20. Rotate the driver installation tool until the mark (3) on the driver installation tool aligns with the top of the drill bushing (2).
21. Inspect the insert for proper installation into the tapped hole.
22. Remove the fixture plate bolts (1).
23. Remove the fixture plate (3) and bushing (2).

J 45059 Angle Meter. See Special Tools .

1. Install the upper crankshaft main bearings into the block.
2. Lubricate the upper crankshaft main bearing surface with clean engine oil.
3. Install the crankshaft.
4. Install the lower crankshaft main bearings into the main bearing caps.
5. Lubricate the lower crankshaft main bearing surface with clean engine oil.
6. Install the crankshaft main bearing caps.
7. Install the crankshaft main bearing cap stiffener.
8. Install new crankshaft main bearing bolts. Start the crankshaft main bearing cap bolts by hand. Ensure the bottom of the crankshaft main bearing cap is parallel to the block surface.
9. Tighten the crankshaft main bearing cap bolts in equal increments. Tighten: Tighten the crankshaft main bearing cap bolts to 25 N.m (18 lb ft) in sequence. Use J 45059 to tighten the crankshaft main bearing cap bolts an additional 180 degrees. See «Special Tools»(ref-200396-S26818425802005102000000) .
10. Measure the crankshaft end play. Thrust the crankshaft forward or rearward. Insert a feeler gage between the thrust crankshaft bearing and the bearing surface of the crankshaft and measure the bearing clearance. Refer to «Engine Mechanical Specifications»(ref-200396-S04002696082005102000000) for the proper clearance. If the bearing clearance is not within specifications, inspect the thrust surfaces for nicks, gouges or raised metal. Minor imperfections may be removed with a fine stone.

J 45059 Angle Meter. See Special Tools .

1. Install the dowel pins (cylinder head locator) (if necessary).
2. Install a new cylinder head gasket.
3. Install the cylinder head.
4. Install new cylinder head bolts.
5. Tighten the new cylinder head bolts in the following sequence: Tighten: Tighten the (14) long cylinder head bolts in sequence to 30 N.m (22 lb ft). Use J 45059 to tighten the cylinder head bolts in sequence an additional 155 degrees. See «Special Tools»(ref-200396-S26818425802005102000000) . Tighten the (2 Short) end bolts to 7 N.m (62 lb in). Use J 45059 to tighten the short cylinder head end bolts an additional 60 degrees. See «Special Tools»(ref-200396-S26818425802005102000000) . Tighten the (1 Long) end bolt to 7 N.m (62 lb in). Use J 45059 to tighten the long cylinder head end bolt an additional 120 degrees. See «Special Tools»(ref-200396-S26818425802005102000000) .

J 44221 Camshaft Holding Tool. See Special Tools .

1. Coat the camshaft journals, camshaft journal thrust face, and camshaft lobes with clean engine oil.
2. Install the exhaust camshaft.
3. Install the intake camshaft.
4. Install J 44221 with the camshaft flats up and the number 1 cylinder at top dead center. See «Special Tools»(ref-200396-S26818425802005102000000) .
5. Install the exhaust camshaft caps.
6. Install the intake camshaft caps.
7. Install the camshaft cap bolts. Tighten: Tighten the camshaft cap bolts to 12 N.m (106 lb in).
8. Remove J 44221 . See «Special Tools»(ref-200396-S26818425802005102000000) .

J 44218 Seal Installer. See Special Tools .

1. Apply engine oil to the outside diameter of the crankshaft front oil seal.
2. Use J 44218 to install the crankshaft front oil seal. See «Special Tools»(ref-200396-S26818425802005102000000) .
3. Remove J 44218 . See «Special Tools»(ref-200396-S26818425802005102000000) .

J 44219 Engine Cover Alignment Pins. See Special Tools .

1. Install the engine front cover spacer bolt. Tighten: Tighten the engine front cover spacer bolt to 10 N.m (89 lb in).
2. Install the crankshaft balancer friction washer GM P/N 12573950 over the crankshaft snout, up against the crankshaft gear.
3. Install J 44219 . See «Special Tools»(ref-200396-S26818425802005102000000) .
4. Apply a 3 mm (0.12 in) bead of sealer GM P/N United States 12378521, GM P/N Canada 88901148 to the back side of the engine front cover (1).
5. Align the oil pump to the crankshaft sprocket splines.
6. Install the engine front cover.
7. Remove J 44219 . See «Special Tools»(ref-200396-S26818425802005102000000) .
8. Install the engine front cover bolts. Tighten: Tighten the engine front cover bolts to 10 N.m (89 lb in). Tighten the small center bolt (1) last to 10 N.m (89 lb in).

J 41240 Fan Clutch Remover and Installer. See Special Tools .

1. Install the water pump gasket.
2. Install the water pump.
3. Install the water pump bolts. Tighten: Tighten the water pump bolts to 10 N.m (89 lb in).
4. Install the water pump pulley.
5. Install the water pump pulley bolts.
6. Install J 41240 to hold pulley. See «Special Tools»(ref-200396-S26818425802005102000000) .
7. Tighten the water pump pulley bolts. Tighten: Tighten the water pump pulley bolts to 25 N.m (18 lb ft).
8. Remove J 41240 . See «Special Tools»(ref-200396-S26818425802005102000000) .

J 44219 Housing Alignment Pins. See Special Tools .

1. Apply a 3 mm (0.12 in) bead of GM P/N United States 12378521, GM P/N Canada 88901148 to the rear oil seal housing (1).
2. Install J 44219 into the block. See «Special Tools»(ref-200396-S26818425802005102000000) .
3. Slide the crankshaft rear oil seal housing over the alignment pins ( J 44219 ) and crankshaft. See «Special Tools»(ref-200396-S26818425802005102000000) .
4. Install the crankshaft rear oil seal housing bolts (except the two in place of the guide pins).
5. Remove J 44219 . See «Special Tools»(ref-200396-S26818425802005102000000) .
6. Install the remaining two crankshaft rear oil seal housing bolts. Tighten: Tighten the crankshaft rear oil seal housing bolts to 10 N.m (89 lb in).
7. Wipe off any excess material from the bottom of the oil pan sealing area (1).

J 44227 Rear Seal Installer. See Special Tools .

1. Use the plastic installation sleeve supplied with the new seal when installing a new seal. Use J 44227 to install the crankshaft rear oil seal. See «Special Tools»(ref-200396-S26818425802005102000000) .
2. Remove J 44227 . See «Special Tools»(ref-200396-S26818425802005102000000) .

J 45059 Angle Meter. See Special Tools .

1. Install the flywheel.
2. Install new flywheel bolts. Tighten: Tighten the new flywheel bolts to 25 N.m (18 lb ft). Use J 45059 to tighten the flywheel bolts an additional 50 degrees. See «Special Tools»(ref-200396-S26818425802005102000000) .

J 45299 Engine Preluber. See Special Tools .

1. Remove the engine oil filter, fill with clean engine oil, and reinstall. Tighten: Tighten the oil filter to 30 N.m (22 lb ft).
2. Remove the engine block oil gallery plug (1).
3. Install the M16 x 1.5 adapter P/N 509375.
4. Install the flexible hose to the adapter and open the valve.
5. Pump the handle on J 45299 to flow a minimum of 1-2 quarts of engine oil. See «Special Tools»(ref-200396-S26818425802005102000000) . Observe the flow of engine oil through the flexible hose and into the engine assembly.
6. Close the valve and remove the flexible hose and adapter from the engine.
7. Install the engine block oil gallery plug (1). Tighten: Tighten the oil pressure sensor to 35 N.m (26 lb ft).
8. Top-off the engine oil to the proper level.

Engine Block

The lost foam all aluminum engine block utilizes a deep skirt design for increased rigidity. The cylinders are positioned in a straight in-line 6 cylinder orientation. The crankshaft bearing caps have a bearing beam or "ladder" for enhanced structural rigidity and vibration reduction.

Oil Pan

A single piece cast aluminum oil pan contributes to crankshaft and block rigidity while reducing overall weight. The oil pan bolts to the bell housing as well as the block. This eliminates points of vibration and makes the complete powertrain act as a single casting. Jack screws are used to remove the oil pan.

Crankshaft

The crankshaft is a nodular iron design with seven main bearings.

Connecting Rods

The connecting rods are forged powdered metal. The connecting rods and caps are of a fractured split design to improve durability and reduce internal friction. Care must be taken to ensure the mating surfaces are not damaged during service procedures.

Pistons

The pistons are a full-floating design. The piston pins are a slip fit in the bronze bushed connecting rod and are retained in the piston by round wire retainers. There are two compression rings and one oil control ring.

Cylinder Head

The cylinder head is also made of the lost foam aluminum for lighter weight and rapid heat dissipation. There are 4 valves per cylinder and the ports are of a high swirl design for improved combustion. The cylinder head gasket consist of a steel laminated construction.

Valve Train

The engine utilizes dual overhead camshafts and roller followers for reduced friction, which results in improved gas mileage.

Fuel System

A new electronic throttle control system is used on the engine. A throttle actuator control or TAC system eliminates cable linkage from the pedal to the throttle control module. All throttle movements are controlled by the PCM.

Oil Pump

The oil pump is gear driven directly from the crankshaft. The oil pump drive gear is a slip fit to the crankshaft.

Engine Covers

There is a front engine cover and a rear engine cover, both are made of aluminum. The front engine cover and rear engine cover have "T" sealing joints and need to be removed after the oil pan. The front and rear covers need to be installed before the oil pan. Jack screws are used to remove the covers. Guide pins are used to aid in the installation of both covers.

New Product Information

The purpose of New Product Information is to highlight or indicate important new features for the service community.

Changes may include one or more of the following items

1. Torque values and/or fastener tightening strategies
2. Engine specifications
3. New sealants and/or adhesives
4. Disassembly and assembly procedure revisions
5. Engine mechanical diagnostic procedure revisions
6. Special tools required

New Sealants and/or Adhesives

1. U.S. and Canadian SPO part numbers
2. 3-Bond sealant P/N 12378521

New Features on the LL8 Engine

1. Pan-axle design oil pan
2. Exhaust camshaft position actuator
3. Exhaust camshaft position actuator valve
4. Jack bolts on the front cover, rear cover, and oil pan

Engine Features

1. Powder metal connecting rods
2. Full floating piston pins
3. Lost foam casted aluminum block and head
4. Composite plastic camshaft cover
5. Electronic Throttle Control - ETC
6. Composite intake manifold
7. Bridge/bearing beam - stiffener ladder
8. Stainless steel fuel rail
9. Coil-on-plug ignition system
10. Inlet side thermostat
11. No EGR
12. No AIR

Cleanliness and Care

An automobile engine is a combination of many of the following surfaces

1. Machined
2. Honed
3. Polished
4. Lapped

The tolerances of these surfaces are measured in the ten-thousandths of an inch. When you service any internal engine part, cleanliness and care are important. Apply a liberal coating of engine oil to the friction areas during assembly in order to protect and lubricate the surfaces on initial operation. Throughout this section, practice proper cleaning and protection procedures to the machined surfaces and to the friction areas.

Note. Engine damage may result if an abrasive paper, pad, or motorized wire brush is used to clean any engine gasket surfaces.

Whenever you remove the valve train components, keep the components in order. Follow this procedure in order to install the components in the same locations and with the same mating surfaces as when removed.

Disconnect the negative battery cables before you perform any major work on the engine. For more information on the disconnection of the battery, refer to Engine Electrical.

Separating Parts

The components of an internal combustion engine develop wear patterns with their mating components. During disassembly of the engine, parts should be separated and kept in order so they may be reinstalled in the same location from which they were removed.

Replacing Engine Gaskets

1. Do not reuse any gasket unless otherwise specified. Reusable gaskets will be identified in the service procedure. Do not apply sealant to any gasket or sealing surface unless called out in the service procedure.
2. Use jack screws to separate components.
3. Remove all of the gasket and the sealing material from the component using a plastic or a wood scraper. Do not gouge or scrape the sealing surfaces.
4. When assembling components, use only the sealant specified in the service procedure. Ensure that the sealing surfaces are clean and free of debris or oil. When applying sealant to a component, apply a bead size as specified in the service procedure.
5. Tighten the bolts to the specifications.

Sealant Types

The following 2 major types of sealant are commonly used in engines

1. Aerobic sealant (Room Temperature Vulcanizing (RTV))
2. Anaerobic sealant, which include the following: Gasket eliminator Pipe Threadlock

Aerobic Type Room Temperature Vulcanizing (RTV) Sealant

Aerobic type Room Temperature Vulcanizing (RTV) sealant cures when exposed to air. This type of sealant is used where 2 components (such as the intake manifold and the engine block) are assembled together.

Use the following information when using RTV sealant

1. Do not use RTV sealant in areas where extreme temperatures are expected. These areas include: The exhaust manifold The head gasket Any other surfaces where a different type of sealant is specified in the service procedure
2. Always follow all the safety recommendations and the directions that are on the RTV sealant container.
3. Use a plastic or wood scraper in order to remove all the RTV sealant from the components.
4. The surfaces to be sealed must be clean and dry.
5. Use a RTV sealant bead size as specified in the service procedure.
6. Apply the RTV sealant bead to the inside of any bolt holes areas.
7. Assemble the components while the RTV sealant is still wet to the touch. Do not wait for the RTV sealant to skin over.
8. Tighten the fasteners in sequence (if specified) and to the proper torque specifications. DO NOT overtighten the fasteners.

Anaerobic Type Threadlock Sealant

Anaerobic type threadlock sealant cures in the absence of air. This type of sealant is used for threadlocking and sealing of bolts, fittings, nuts, and studs. This type of sealant cures only when confined between 2 close fitting metal surfaces.

Use the following information when using threadlock sealant

1. Always follow all safety recommendations and directions that are on the threadlock sealant container.
2. The threaded surfaces to be sealed must be clean and dry.
3. Apply the threadlock sealant as specified on the threadlock sealant container.
4. Tighten the fasteners in sequence (if specified) and to the proper torque specifications. DO NOT overtighten the fasteners.

Anaerobic Type Pipe Sealant

Anaerobic type pipe sealant cures in the absence of air and remains pliable when cured. This type of sealant is used where 2 parts are assembled together and require a leak proof joint.

Use the following information when using pipe sealant

1. Do not use pipe sealant in areas where extreme temperatures are expected. These areas include: The exhaust manifold The head gasket Surfaces where a different sealant is specified
2. Always follow all the safety recommendations and the directions that are on the pipe sealant container.
3. The surfaces to be sealed must be clean and dry.
4. Use a pipe sealant bead of the size or quantity as specified in the service procedure.
5. Apply the pipe sealant bead to the inside of any bolt hole areas.
6. Apply a continuous bead of pipe sealant to 1 sealing surface.
7. Tighten the fasteners in sequence (if specified) and to the proper torque specifications. DO NOT overtighten the fasteners.

Tools and Equipment

Work in a clean and well-lit area. Have the following components available before you begin to work

1. A suitable parts cleaning tank
2. A compressed air supply
3. Trays, in order to keep the parts and the fasteners organized
4. An adequate set of hand tools

An approved engine repair stand will prevent personal injury or damage to the engine components. The special tools are designed in order to quickly and safely accomplish the operations for which the tools are intended. Using the tools will minimize possible damage to the engine components. Precision measuring tools are required for the inspection of certain critical components. Torque wrenches are needed for the correct assembly of various parts.