Cylinder Head Assembly: Service and Repair
1. Relieve fuel system pressure.2. Disconnect battery ground cable, then drain cooling system.
3. Remove air cleaner assembly, intake duct and heat tube.
4. Remove drive belt, then if removing left cylinder head, proceed as follows:
a. Remove power steering pump and position aside, then remove oil fill cap.
b. Remove A/C compressor mounting bracket and position aside, if equipped.
c. Remove alternator and bracket.
5. If removing right cylinder head, proceed as follows:
a. Disconnect thermactor air control valve, if equipped.
b. Disconnect thermactor tube support bracket from rear of cylinder head, if equipped.
c. Remove accessory drive idler.
d. Remove thermactor pump pulley and thermactor pump, if equipped.
e. Remove PCV valve.
6. Remove intake manifold.
7. Remove exhaust manifolds.
8. Remove rocker arm cover attaching bolts and the cover.
9. Loosen rocker arm fulcrum attaching bolts enough to rotate rocker arm so pushrod can be removed.
NOTE: Keep pushrods in order so they can be installed in original position.
10. Remove and discard cylinder head attaching bolts.
11. Remove cylinder head.
CAUTION: This engine uses "Torque To Yield Bolts". Always use new cylinder head bolts to ensure leak-tight assembly. Torque retention with used bolts can vary, which may result in coolant or compression leakage at the cylinder head mating surface.
12. Reverse procedure to install, noting the following:
a. Lightly oil all bolts except short ones.
b. Apply suitable sealer to short cylinder head bolts.
FWD 3.8L:
13. Reassemble and tighten the new head bolts to the following specifications:
Tighten all bolts in numerical sequence, as shown, in three steps as follows:
- 20 Nm (15 lb.ft.)
- 40 Nm (30 lb.ft.)
- 50 Nm (37 lb.ft.)
Caution: Do not loosen all of the bolts at the same time. Work on one bolt at a time in the sequence shown. Failure to loosen bolts in proper sequence could cause cylinder head to warp.
14. In numerical sequence, retighten the bolts per the following steps:
Long Bolts:
a. Loosen the long bolt and back out 2 - 3 turns.
b. Retighten the long bolt to 40-50 Nm (30 - 37 lb.ft.).
c. Rotate the long bolt an additional 175°-185° (approximately 1/2 turn).
d. Go to the next bolt in sequence.
Short Bolts:
a. Loosen the short bolt and back out 2 - 3 turns.
b. Retighten the short bolt to 20 - 30 Nm (15 - 22 lb.ft.).
c. Rotate the short bolt an additional 175° - 185° (approximately 1/2 turn).
15. For each valve, rotate the crankshaft until the tappet rests on the base of the camshaft lobe, install the pushrods and torque rocker arm fulcrum attaching bolts to 5 Nm (43 in. lb.).
16. Once all of the rockers are in place and temporarily torqued, torque all fulcrum arm bolts to 25 - 35 Nm (19 - 25 ft lbs). For this step the camshaft may be in any position.
17. Torque rocker arm cover bolts to 9 - 12 Nm (80 - 106 in. lb.).