Cylinder Head Assembly: Service and Repair

Exploded View Of Cylinder Block, Crankshaft & Related Components:

Exploded View Of Cylinder Head Assembly & Related Components:

1. Raise and secure hood in open position.
2. Disconnect battery ground cable.
3. Drain cooling system and disconnect heater hose at the fitting located under the intake manifold.
4. Disconnect cooling fan switch electrical connector.
5. Remove air cleaner assembly.
6. Remove PCV hose from air cleaner assembly.
7. Label, then disconnect all electrical connectors and vacuum hoses from cylinder head assembly.
8. Remove rocker arm cover.
9. Remove accessory drive belts.
10. Remove crankshaft damper.
11. Remove timing belt cover.
12. Turn crankshaft until No. 1 cylinder is at TDC of compression stroke.
13. Remove distributor cap and spark plug wires as an assembly.
14. Using torque wrench adapter T88P-6254-A or equivalent, loosen both belt tensioner attaching bolts.
15. Secure belt tensioner as far left toward front of vehicle as possible.
16. Remove timing belt.
17. Disconnect EGR tube from EGR valve.
18. Disconnect fuel supply and return lines from metal connectors, located on the right side of the engine and set rubber lines aside.
19. Disconnect accelerator cable and speed control cable, if equipped.
20. Disconnect alternator from wiring harness.
21. Remove alternator and mounting bracket.
22. Raise and support vehicle.
23. Disconnect exhaust pipe from exhaust manifold.
24. Lower vehicle.
25. Remove and discard cylinder head bolts and washers.
26. Remove cylinder head with exhaust and intake manifolds attached.
27. Remove cylinder head gasket. Do not lay cylinder head flat. Damage to the spark plugs, valves or gasket surfaces may result.

Fig. 6 Piston Squish Height (Part 1 Of 2):

Fig. 6 Piston Squish Height (Part 2 Of 2):

Fig. 7 Cylinder Head Bolt Tightening Sequence:

28. Reverse procedure to install. Before FINAL installation of the cylinder head, check piston squish height. Squish height is the clearance of the piston dome to the cylinder head dome at piston TDC, Fig. 6. No rework of the cylinder head gasket surfaces or use of replacement components (crankshaft, piston and connecting rod) causing the assembled squish height to be over or under the tolerance specification is permitted. If no other parts other than the cylinder head gasket are replaced, the piston squish height should be within specification. If parts other than the cylinder head gasket are replaced, check the squish height. If the squish height is out of specification, replace the parts again, and check the piston squish height again. Check squish height as follows:
a. Clean all gasket material from the mating surfaces on the cylinder head and engine block.
b. Place a small amount of soft lead solder of appropriate thickness on the piston spherical areas.
c. Rotate crankshaft to lower the piston in the bore and install the cylinder head gasket. A compressed (used) gasket is preferred.
d. Install the used cylinder head bolts and tighten the head bolts to 30-44 ft. lbs. in sequence.
e. Rotate the crankshaft to move the piston through its TDC position.
f. Remove the cylinder head and measure the thickness of the compressed solder to determine squish height at TDC. The solder should be .046-.060 inch for EFI & .039-.070 inch EFI HO engines. Before installing the cylinder head the crankshaft must be rotated so that the No. 1 piston is 90 degrees before top dead center (BTDC). To position the piston, turn crankshaft until the pulley keyway is at 9 o'clock position. To time the valve train to this piston position, turn the camshaft until keyway is at the 6 o'clock position. The camshaft and the crankshaft must not be turned until after the installation of the timing gears and timing belt.
31. Torque new cylinder head bolts in sequence shown in Fig. 7, to 44 ft. lbs. Loosen all attaching bolts approximately two turns, then torque attaching bolts in sequence shown to 44 ft. lbs. After tightening cylinder head bolts, turn all bolts 90 degrees, again in sequence shown. Complete bolt tightening by turning all bolts in sequence an additional 90 degrees.