Cylinder Head Assembly: Service and Repair

Tightening Sequence For Cylinder Head:

Intake Manifold Torque Sequence:

REMOVE OR DISCONNECT
1. Battery negative cable.
2. Drain the cooling system.
3. Intake manifold.
3. Exhaust manifolds.
4. Ground strap at rear of right cylinder head.
5. AIR pipe at the rear of the cylinder head.
6. Components as follows for right side cylinder head.
^ AIR pump bolt and spacer at the cylinder head.
^ Nut and stud attaching air conditioning compressor to cylinder head.
^ Fuel pipe, plug wire, and wiring harness brackets at the rear of the cylinder head.

7. Components as follows for left side cylinder head.
^ Nut and stud attaching main accessory bracket to the cylinder head. It may be necessary to loosen the remaining bolts and studs and move the bracket forward slightly for clearance to remove the cylinder head.
^ Coolant sensor wire.
^ Spark plug wire brackets at the rear of the cylinder head.

8. Rocker arm covers.
9. Spark plugs.
10. Pushrods.
11. Cylinder head bolts.
12. Remove cylinder head and gasket.
13. Clean the following:
^ Carbon deposits from combustion chambers.
^ All traces of old head gasket from cylinder head and block.
^ Cylinder head bolt threads and threads in the block.

14. Inspect sealing surfaces of the block and cylinder head for nicks, heavy scratches, or other damage.

CAUTION: When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. The correct torque value must be used when installing fasteners that require it. If the above conditions are not met, parts or system damage could result.

INSTALL OR CONNECT
1. Head gasket:
^ If a steel gasket is used, coat both sides of the gasket with sealer. Spread the sealer thin and even.
^ Do not use sealer on composition steel-asbestos gaskets.
^ Place the gasket over the block dowel pins with the bead up.

2. Cylinder head. Carefully guide the cylinder head into place over the dowel pins and gasket.
3. Cylinder head bolts. Coat threads of the cylinder head bolts with sealing compound (GM part number 1052080 or equivalent) and install finger-tight.
4. Tighten bolts in three steps using the sequence shown until the proper torque is reached:
a. First torque to 30 Nm (25 ft lbs).
b. Then torque to 60 Nm (45 ft lbs).
c. Final torque 92 Nm (65 ft lbs).

5. Pushrods.
6. Adjust valves, refer to Valve Clearance / Adjustments.
7. Rocker arm covers and torque bolts to 10 Nm (90 in lbs).
8. Spark plugs and torque to 20 Nm (15 lb ft).
9. Components as follows for right side cylinder head:
^ AIR pump bolt and spacer at the cylinder head.
^ Nut and stud attaching the air conditioning compressor to the cylinder head.
^ Fuel pipe, plug wire and wiring harness brackets at the rear of the cylinder head.

10. Components as follows for left side cylinder head:
^ Nut and stud attaching main accessory bracket to the cylinder head.
^ Remaining main accessory bracket bolts and nuts, as necessary.
^ Coolant sensor wire.
^ Spark plug wire brackets at the rear of the cylinder head.

11. AIR pipe.
12. Ground strap at the rear of the right cylinder head.
13. Exhaust manifolds and torque:
a. Two center bolts to 36 Nm (26 ft lbs).
b. All other bolts to 28 Nm (20 ft lbs).

14. Intake manifold and torque in sequence to 48 Nm (35 ft lbs).
15. Battery negative cable.
16. Fill the cooling system.
17. Check for leaks.