Cylinder Head Assembly: Service and Repair

(Figure 1) Cylinder head bolt tightening sequence.:

REMOVE OR DISCONNECT
1. Negative battery cable
2. Serpentine belt

Rear Cylinder Head
^ Generator
^ Power Steering Pump
^ Mounting Bracket
^ Rear Exhaust Manifold

Front Cylinder Head
^ Oil dipstick
^ Front Exhaust Manifold

3. Spark plug wires
4. Multi-pin connector from C31 unit and remove C31 unit.

NOTES:
^ Clean head and adjacent areas with air hose and cloths, to avoid getting DIRT into the engine.
^ During disassembly of the engine, all parts must be marked as to their proper location.

5. Intake manifold
6. Valve cover
7. Rocker arms
8. Push rods
9. Cylinder head bolts
10. Cylinder head

INSTALL OR CONNECT
1. Clean threads in cylinder block using appropriate tap.
2. Cylinder head gasket on block.
3. Cylinder head.
4. Apply thread sealer GM P/N 1052080 or equivalent on bolt threads.
5. Cylinder head bolts.

CAUTION: This engine uses special torque to yield head bolts. This design bolt requires a special tightening procedure. Failure to follow the given procedure will cause head gasket failure and possible engine damage.

6. Torque cylinder head bolts to 34 Nm (25 lb ft) as per sequence shown in Figure 1.

NOTE: Should you reach 81 Nm (60 lbs ft) at any time in Steps 7 and 8, you should stop at this point. Do NOT complete the balance of the 90° turn.

7. Tighten each bolt 1/4 turn (90°) in sequence.
8. Tighten each bolt an additional 1/4 turn (90°) in sequence.
9. Push rods
10. Rocker arms
11. Intake manifold
12. Valve cover
13. C3I unit & multi-pin connector
14. Spark plug wires

Rear Cylinder Head
^ Mounting Bracket
^ Power steering pump
^ Generator
^ Rear exhaust manifold

Front Cylinder Head
^ Front exhaust manifold
^ Oil dipstick

15. Serpentine belt.
16. Negative battery cable

Inspect
^ For proper completion of repair
^ For external fluid leaks