For 1990-2009 cars

### Removal Procedure

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

1. Disconnect the negative battery cable.
2. Raise and properly support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Place a drain pan or suitable container underneath the engine oil pan.
4. Remove the engine oil drain plug and gasket. Allow the engine oil to drain.
5. Remove the front pipe/catalytic converter assembly. Refer to Front Pipe Replacement in Engine Exhaust.
6. Remove the two bolts and the flywheel inspection cover.
7. Remove the following components from the vehicle:

• | Sixteen bolts

• | Crankshaft Sensor (6)

• | Two nuts

• | The engine oil pan (1)

• | Oil Pump Strainer (2)

8. Remove the following components from the vehicle:

• | Ten main bearing bolts

• | Five main bearing caps with lower inserts

9. Remove the five upper inserts from the cylinder block (1).

### Installation Procedure

1. Install the upper inserts to the cylinder block (1).

Important: The upper insert has an engine oil groove. Install with the engine oil groove to the cylinder.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Important: Gradual and uniform tightening is important for main bearing bolts. After tightening the main bearing cap bolts, inspect in order to check that the crankshaft rolls smoothly when turned by hand.

2. Install the five main bearing caps (2) with the lower inserts and secure with the ten main bearing cap bolts in order 1, 2, 3, 4 and 5.

Each main bearing cap is embossed with an arrow mark and a number. When installing each bearing cap to the cylinder block, point the arrow mark toward the crankshaft timing pulley side.

Tighten
Tighten the main bearing cap bolts to 54 N·m (40 lb ft).

3. Install the air condition belt (if equipped) and tighten.
4. Adjust the air conditioning belt tension. Refer to HVAC.
5. Install the right-side splash shield and secure it with six clips.
6. Install the generator/cooling pump belt.
7. Adjust the generator/cooling pump belt tension.
8. Install the oil pump strainer and the oil pump strainer seal to the cylinder block and secure with the oil pump strainer bolt first and then the oil pump strainer bracket bolt.

Tighten
Tighten the oil pump strainer bolt first and then the oil pump strainer bracket bolt to 11 N·m (97 lb in).

9. Apply a continuous bead of GM P/N 12346240 or equivalent, to the engine oil pan mating surface.
10. Install the engine oil pan to the cylinder block and secure the engine oil pan with 16 bolts and two nuts starting at the center and working outward.

Tighten
Tighten the engine oil pan bolts and nuts to 11 N·m (97 lb in).

11. Install the gasket and the engine oil pan drain plug.

Tighten
Tighten the engine oil drain plug to 35 N·m (26 lb ft).

12. Install a new assembly seal to the front pipe/catalytic converter.
13. Install the new front pipe/catalytic converter with new seal to the exhaust manifold and secure the front pipe/catalytic converter with two bolts. Do not tighten fully.
14. Install the new resonator/center pipe gasket to assembly.
15. Install the new resonator/center pipe to the front pipe/catalytic converter assembly and secure with two nuts.

Tighten

• | Tighten the exhaust manifold-to-front pipe/catalytic converter assembly bolts to 60 N·m (43 lb ft).

• | Tighten the resonator/muffler/tail pipe-to-front pipe/catalytic converter nuts to 35 N·m (26 lb ft).

16. Install the front pipe/catalytic converter assembly to the vehicle and support the catalytic converter with a hanger.
17. Lower the vehicle.
18. Fill the engine oil to specifications. Refer to Approximate Fluid Capacities in Maintenance and Lubrication.
19. Connect the negative battery cable.
20. Inspect coolant system for leaks.
21. Start the engine. Inspect the exhaust system for exhaust leaks.
22. Run the engine in order to inspect the engine oil pressure. Refer to Oil Pressure Diagnosis and Testing .