Cylinder Head Assembly: Service and Repair
Camshaft Sprocket Suspended Position:
Replacement of the cylinder head requires separation of the camshaft sprocket from the camshaft. In order to maintain camshaft, intermediate shaft and crankshaft timing, the timing belt should remain indexed on the camshaft sprocket while the assembly is suspended under light tension.
When removing the camshaft sprocket from the camshaft, adequate tension on the sprocket and belt assembly must be maintained to prevent the timing belt from disengaging from the intermediate or crankshaft timing sprockets. Failure to maintain adequate tension on timing belt may result in incorrect engine timing. Refer to "Timing Belt, Replace" for camshaft sprocket removal.
REMOVAL
1. Relieve fuel system pressure as outlined under "Precautions".
2. Disconnect battery ground cable, then drain coolant into a suitable container.
3. Remove air cleaner and disconnect all vacuum lines, electrical wiring and fuel lines from throttle body.
4. Disconnect throttle linkage.
5. On models equipped with power steering, loosen power steering pump, then remove belt.
6. On all models, disconnect power brake vacuum hose from intake manifold.
7. Disconnect water hoses from water crossover.
8. Raise and support vehicle, then disconnect exhaust pipe from exhaust manifold.
9. Lower vehicle, then remove power steering pump assembly and position aside.
10. Disconnect dipstick tube from thermostat housing, then rotate bracket from stud. Do not bend bracket.
Accessory & Solid Mount Compressor Bracket:
11. Remove solid mount compressor bracket.
12. Remove cylinder head cover attaching bolts, then the cover.
Cylinder Head Bolt Removal Sequence:
13. Remove cylinder head bolts in sequence shown, then the cylinder head assembly.
SERVICE
Valve Spring Replacement:
1. If cylinder head is removed, use valve spring compressor tool No. 4682, or equivalent, to compress valve spring enough to remove and install valve bead locks.
2. If cylinder head is installed, proceed as follows:
a. Rotate crankshaft until piston is at TDC on compression stroke.
b. Apply 90-100 psi of compressed air into spark plug hole of valve being removed.
c. Using valve spring compressor tool No. 4683, or equivalent, compress valve spring enough to remove valve stem locks.
d. Remove valve spring and spring seat.
e. Remove valve seal.
3. Reverse procedure to install.
INSTALL
Cylinder Head Bolt Inspection:
Head gaskets are not interchangeable across model years or engine sizes. Ensure correct gasket is installed. Ensure 11 mm diameter "Torque To Yield" (TTY) bolts are used when installing the cylinder head. Bolt size can be determined by the stamping on the bolt head. A 10 mm bolt will thread into an 11 mm hole, but will strip the bore. Inspect bolts using a straightedge to determine if they are stretched. If all bolt threads are not on a straight line, replace the bolt.
1. Position cylinder head on block.
Cylinder Head Bolt Tightening Sequence:
2. Refer to tightening sequence, and tighten cylinder head bolts in four steps as follows:
a. Torque all bolts to 45 ft-lbs.
b. Torque all bolts to 65 ft-lbs.
c. Torque all bolts again to 65 ft-lbs.
d. Without using a torque wrench, tighten each bolt an additional 1/4 turn (90°), then check 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 steps to complete installation.