Cylinder Head Assembly: Service and Repair

Fig. 15 Suspending camshaft sprocket:

Removal and installation of cylinder head requires separation of camshaft sprocket from camshaft. In order to maintain camshaft, intermediate shaft and crankshaft timing, timing belt is left indexed on camshaft sprocket while assembly is suspended under light tension.

When removing camshaft sprocket from camshaft, adequate tension on sprocket and belt assembly must be maintained to prevent timing belt from disengaging from intermediate or crankshaft timing sprockets. Failure to maintain adequate tension on timing belt may result in incorrect engine timing.

REMOVAL

1. On models equipped with fuel injection, relieve fuel system pressure. Refer to MAINTENANCE PROCEDURES.
2. On all models, disconnect battery ground cable, then drain cooling system.
3. Remove air cleaner and disconnect all vacuum lines, electrical wiring and fuel lines from throttle body.
4. Disconnect throttle linkage.
5. Remove upper radiator hose.
6. Disconnect power brake vacuum hose from intake manifold.
7. Raise and support vehicle, then disconnect exhaust pipe from exhaust manifold.
8. Disconnect dipstick tube from thermostat housing, then rotate bracket from stud. Do not bend bracket. Disconnect coil wiring connector and coil wire.

Fig. 18 Alternator & A/C compressor mounting bracket removal:

9. Remove upper two air conditioner bracket mounting bolts (numbers 6 & 7).

Fig. 12 Timing belt cover removal:

10. Remove upper timing belt cover.
11. Rotate engine to number 1 TDC, then remove cam gear retaining bolt.
12. Mark position between cam gear and timing belt and secure timing belt to gear with tie-wraps.
13. Carefully slide cam gear from camshaft and suspend cam gear and timing belt.
14. Remove cylinder head cover attaching bolts, then the cover.

Fig. 19 Cylinder head bolt removal sequence:

15. Remove cylinder head bolts in sequence shown, then cylinder head assembly.

INSPECTION

1. Ensure cylinder head is flat within .004 inch (0.1 mm).
2. Inspect camshaft journals for scoring.

INSTALLATION

Head bolt diameter is 11 mm. These bolts are identified with 11 on the head of the bolt. 10 mm bolts will thread into the 11 mm hole, but will strip the cylinder block bolt hole.

Fig. 20 Checking cylinder head bolts:

Inspect bolts as shown. Replace bolts if any sign of stretching is evident.

Fig. 21 Cylinder head bolt tightening sequence:

1. Position cylinder head on block.
2. Tighten cylinder head bolts in sequence using 4 steps as follows:
a. Torque all bolts 45 ft. lbs.
b. Torque all bolts to 65 ft. lbs.
c. Torque all bolts again to 65 ft. lbs.
d. Tighten each bolt an additional 1/4 turn (90°), noting bolt torque. If bolt torque is not over 90 ft. lbs. after tightening an additional 1/4 turn, bolt should be replaced.
3. Reverse remaining removal procedure to complete installation. Tighten to specifications.