General Motors 8.8L Engine

⚠ It may be necessary to hold the crankshaft balancer bolt to prevent crankshaft rotation

Tools: Cylinder Head Leakdown Tester

1. Disconnect the battery ground negative cable.
2. Remove the spark plugs.
3. Rotate the crankshaft to place the piston at Top Dead Center of compression stroke.
4. Install the cylinder leak down tester.
5. Apply shop air pressure and adjust according to manufacturer's instructions.
6. Record the cylinder leakage value.
7. Perform the leakage test on the remaining cylinders and record the values.

Tools: Compression gauge

1. Disconnect ignition coil harness connectors at both cylinder banks.
2. Disconnect fuel injector electrical harness connector at rear of intake manifold.
3. Remove all the spark plugs.
4. Block the throttle plate wide open.
5. Charge the battery if not fully charged.
6. Crank the engine through four compression strokes (four puffs).
7. Make the compression check the same for each cylinder; record the reading.
8. If some cylinders are low, inject approximately 15 ml of engine oil into the combustion chamber.

Tools: Breaker bar with hex-head socket

1. Install a breaker bar with hex-head socket to the drive belt tensioner bolt.
2. Rotate the drive belt tensioner clockwise in order to relieve tension on the belt.
3. Remove the belt from the pulleys and the drive belt tensioner.
4. Slowly release the tension on the drive belt tensioner.
5. Route the drive belt around all the pulleys except the idler pulley.
6. Rotate the belt tensioner clockwise and install the drive belt under the idler pulley.
7. Slowly release the tension and remove the breaker bar and socket.
8. Inspect the drive belt for proper installation and alignment.

Tools: Breaker bar

1. Remove the accessory drive belt.
2. Install a breaker bar into the A/C belt tensioner adapter opening.
3. Rotate the A/C belt tensioner clockwise in order to relieve tension on the belt.
4. Remove the A/C belt from the pulleys and slowly release the tensioner.
5. Install the A/C belt around the crankshaft balancer.
6. Relieve tension and install the A/C belt over the idler pulley and A/C compressor pulley.
7. Slowly release the tensioner and remove the breaker bar.
8. Install the accessory drive belt and inspect the A/C belt for alignment.

1. Remove the accessory drive belt.
2. Remove the drive belt tensioner bolts.
3. Remove the drive belt tensioner.
4. Install the drive belt tensioner.
5. Install the drive belt tensioner bolts.
6. Tighten the drive belt tensioner bolts to 50 Nm (37 lb ft).
7. Install the accessory drive belt.

1. Raise and suitably support the vehicle with safety stands.
2. Remove the oil pan drain plug and allow the engine oil to drain completely.
3. Clean the oil pan drain plug surface.
4. Remove the oil filter from the engine block and allow the oil to drain.
5. Install a new oil filter; tighten per the oil filter manufacturer's instructions.
6. Install the oil pan drain plug and tighten to 28 Nm (21 lb ft).
7. Lower the vehicle.
8. Fill the engine with oil.

⚠ Apply grease or clean engine oil to the inside of the balancer or crankshaft to prevent galling

Tools: J 38416-B, J 42845, J 42846, J 42847

1. Remove the air conditioning belt, the fan, and the starter motor.
2. Install J 42847 to the starter bolt holes; tighten bolts to 50 Nm (37 lb ft).
3. Remove the crankshaft balancer bolt and washer.
4. Install J 42846 onto the end of the crankshaft.
5. Install J 38416-B and remove the crankshaft balancer.
6. Install the balancer onto the crankshaft and install J 42845.
7. Tighten J 42845 until the balancer seats against the crankshaft sprocket.
8. Install the crankshaft balancer bolt and tighten to 90 ft-lbs.

⚠ Make sure the flywheel is installed correctly

1. If equipped with automatic transmission, remove the transmission.
2. If equipped with manual transmission, remove the clutch assembly.
3. Remove the engine flywheel bolts.
4. Remove the engine flywheel.
5. Clean and inspect the engine flywheel.
6. Install the engine flywheel; "Engine Side" is stamped on the flywheel.
7. Install the engine flywheel bolts and tighten in a criss cross pattern.
8. Tighten bolts first pass 40 Nm (30 lb ft), second pass 60 ft-lbs.

⚠ The engine front cover must be installed and fasteners tightened while the sealant is still wet to the touch

Tools: J 42851

1. Remove the water pump.
2. Remove the crankshaft balancer.
3. Disconnect and remove the camshaft position sensor; remove the battery cable channel.
4. Remove the engine front cover bolts and the engine front cover.
5. Remove the front cover gasket and crankshaft front oil seal.
6. Install a NEW crankshaft front oil seal using J 42851.
7. Apply sealant GM P/N 12346286 at 2 places where the cover meets the oil pan.
8. Install cover gasket and cover; tighten bolts 6 Nm then 12 Nm.

⚠ The intake manifold gaskets are not reusable

⚠ DO NOT reuse intake manifold bolts; install NEW bolts

1. Install the splash shield and ensure it snap fits between the cylinder heads.
2. Install the NEW intake manifold end seals and side gaskets.
3. Ensure gasket tabs align with hole in head gasket and slot in end seals.
4. Install the intake manifold.
5. Apply engine oil to the bolts of the intake manifold.
6. Install the NEW intake manifold bolts.
7. Tighten in sequence using four passes: 40, 80, 120, 154 in-lbs.
8. Install the fuel rail and studs; tighten studs to 12 Nm (106 lb in).

⚠ When installing the oil pump, always replace the retainer between the oil pump and the shaft

1. Remove the oil pan.
2. Remove the oil pump bolt.
3. Remove and separate the oil pump, retainer, and driveshaft.
4. Discard the driveshaft retainer.
5. Remove the crankshaft oil deflector nuts and the deflector.
6. Assemble the oil pump, driveshaft, and a NEW retainer.
7. Install the oil pump assembly onto the locating pins and install the bolt.
8. Tighten the oil pump bolt to 75 Nm (56 lb ft) and install the oil pan.

⚠ Twist the spark plug boot one-half turn to release; pull on the boot only

1. Remove the engine sight shield.
2. Remove the CPA retainer from the ignition coil electrical connector.
3. Disconnect the ignition coil harness electrical connector.
4. Remove the spark plug wires from the spark plugs and ignition coils.
5. Remove the valve rocker arm cover bolts and the cover.
6. Inspect the valve rocker arm cover gasket for cuts or damage.
7. Install cover and bolts; tighten two passes to 6 Nm then 12 Nm.
8. Install spark plug wires, coil connector, CPA retainer, and sight shield.