Cylinder Head Assembly: Service and Repair

Cylinder Head Replacement

Removal Procedure

1. Open the hood.

Caution: Before servicing any electrical component, the ignition and start switch must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.

2. Disconnect the battery negative cable from the battery.
3. Drain the cooling system. Refer to Cooling System Draining and Filling Service and Repair.
4. Remove the engine electrical wiring harness and lay to the side.
5. Disconnect the engine ground straps.
6. Remove the air conditioning compressor from the mounting bracket. Refer to Refrigerant Recovery and Recharging Service and Repair.
7. Remove the air conditioning mounting bracket from the engine block head.
8. Remove the generator from the mounting bracket. Refer to Generator Replacement Service and Repair.
9. Remove the generator mounting bracket from the engine block.
10. Remove the upper intake manifold from the lower intake manifold. Refer to Intake Manifold Replacement Service and Repair.
11. Remove the lower intake manifold from the engine block.
12. Remove the valve rocker arm covers from the cylinder head. Refer to Valve Rocker Arm Cover Replacement Service and Repair.
13. Remove the valve rocker arm from the cylinder head. Refer to Valve Rocker Arm and Push Rod Replacement Service and Repair.
14. Remove the pushrod from the engine block.
15. Remove the spark plugs from the cylinder heads. Refer to Spark Plug Replacement Spark Plug Replacement.
16. Remove the exhaust manifolds from the cylinder head. Refer to Exhaust Manifold Replacement Service and Repair.






17. Remove cylinder head bolts from the engine block.
18. Remove the cylinder heads and gasket from the engine block.
19. Clean and inspect the sealing surfaces on the cylinder heads. Refer to Cylinder Head Clean and Inspect Cylinder Head Clean and Inspect.

Installation Procedure

Important: Do not use sealer on the composition gaskets, and make sure that the punch code (7.4L) on the cylinder head gasket is facing up.






1. Install the cylinder head gasket to the engine block.
2. Install the cylinder head to the engine block.

Important: Make sure that the threads on the cylinder head bolts are clean as well as the threaded holes in the engine block.

3. Coat the threads of the cylinder head bolts with sealing compound GM P/N 12346004.






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.

4. Install the cylinder head bolts to the cylinder head and tighten finger tight.

Tighten
- Tighten the first sequence to 40 Nm (30 lb ft).
- Tighten the second sequence to 80 Nm (59 lb ft).
- Tighten the final sequence to 125 Nm (92 lb ft).

5. Install the push rod into the engine block. Refer to Valve Rocker Arm and Push Rod Replacement Service and Repair.
6. Install the valve rocker arm to the cylinder head.
7. Install the valve rocker arm covers to the cylinder head. Refer to Valve Rocker Arm Cover Replacement Service and Repair.
8. Install the exhaust manifolds to the cylinder heads. Refer to Exhaust Manifold Replacement Service and Repair.
9. Install the spark plugs to the cylinder head. Refer to Spark Plug Replacement Spark Plug Replacement.
10. Install the lower intake manifold to the cylinder head. Refer to Intake Manifold Replacement Service and Repair.
11. Install the upper intake manifold to the lower intake manifold.
12. Install the engine ground straps to the engine block.
13. Install the generator mounting bracket to the engine block.
14. Install the generator to the mounting bracket. Refer to Generator Replacement Service and Repair.
15. Install the air conditioning mounting bracket to the cylinder head.
16. Install the air conditioning compressor to the mounting bracket. Refer to Refrigerant Recovery and Recharging Service and Repair.
17. Install the engine electrical wiring harness.
18. Fill the cooling system. Refer to Cooling System Draining and Filling Draining and Filling Cooling System.
19. Connect the battery negative cable to the battery.
20. Close the hood.