Cylinder Head Assembly: Service and Repair

REMOVAL - CYLINDER HEAD
1. Drain the cooling system. (Refer to - COOLING - STANDARD PROCEDURE)
2. Disconnect negative cable from battery.
3. Remove upper and lower intake manifolds. (Refer to - ENGINE/MANIFOLDS/INTAKE MANIFOLD - REMOVAL)

WARNING: INTAKE MANIFOLD GASKET IS MADE OF VERY THIN METAL AND MAY CAUSE PERSONAL INJURY, HANDLE WITH CARE.

4. Remove the cylinder head covers. (Refer to ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL)
5. Remove the spark plugs from cylinder head.





6. Remove the dipstick and tube (Fig. 2).
7. Remove exhaust manifold(s). (Refer to ENGINE/MANIFOLDS/EXHAUST MANIFOLD REMOVAL)
8. Remove rocker arm and shaft assemblies. (Refer to - ENGINE/CYLINDER HEAD/ROCKER ARMS - REMOVAL) Remove push rods and mark positions to ensure installation in original locations.





9. Remove the eight head bolts from each cylinder head and remove cylinder heads (Fig. 6).

CLEANING
To ensure engine gasket sealing, proper surface preparation must be performed, especially with the use of aluminum engine components and multi-layer steel cylinder head gaskets.

NOTE: Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.

Remove all gasket material from cylinder head and block (Refer to - ENGINE - STANDARD PROCEDURE). Be careful not to gouge or scratch the aluminum head sealing surface.
Clean all engine oil passages.

INSPECTION
1. Before cleaning, check for leaks, damage and cracks.
2. Clean cylinder head and oil passages.





3. Check cylinder head for flatness (Fig. 3).
4. Cylinder head must be flat within:
- Standard dimension = less than 0.05 mm (0.002 inch)
- Service Limit = 0.2 mm (0.008 inch)
- Grinding Limit = Maximum of 0.2 mm (0.008 inch) is permitted.

CAUTION: 0.20 mm (0.008 inch) MAX is a combined total dimension of the stock removal limit from cylinder head and block top surface (Deck) together.

INSTALLATION - CYLINDER HEAD
1. Clean all sealing surfaces of engine block and cylinder heads.





2. Position new gasket(s) on engine block (Fig. 4). The left bank gasket is identified with the "L" stamped in the exposed area of the gasket located at front of engine (shown in (Fig. 4)). The right bank gasket is identified with a "R" stamped in the exposed area of the gasket also, but is located at the rear of the engine.





3. The cylinder head bolts are torqued using the torque yield method, they should be examined BEFORE reuse. If the threads are necked down, the bolts must be replaced (Fig. 5).
4. Necking can be checked by holding a scale or straight edge against the threads. If all the threads do not contact the scale the bolt should be replaced.
5. Tighten the cylinder head bolts 1-8 in the sequence shown in (Fig. 6). Using the 4 step torque turn method, tighten according to the following values:
- Step 1: Bolts 1 - 8 to 61 Nm (45 ft. lbs.)
- Step 2: Bolts 1 - 8 to 88 Nm (65 ft. lbs.)
- Step 3: Bolts 1 - 8 (again) to 88 Nm (65 ft. lbs.)
- Step 4: Bolts 1 - 8 turn an additional 1/4 Turn. (Do not use a torque wrench for this step.)

NOTE: Bolt torque after 1/4 turn should be over 122 Nm (90 ft. lbs.). If not, replace the bolt.

6. Inspect push rods and replace worn or bent rods.
7. Install the push rods.
8. Install the rocker arm and shaft assemblies. (Refer to - ENGINE/CYLINDER HEAD/ROCKER ARMS - INSTALLATION)
9. Install the cylinder head covers. (Refer to ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION)
10. Install the exhaust manifolds. (Refer to ENGINE/MANIFOLDS/EXHAUST MANIFOLD INSTALLATION)
11. Install new O-ring on dipstick tube. Install dipstick tube assembly (Fig. 2).
12. Install the spark plugs.
13. Install upper and lower intake manifolds. (Refer to - ENGINE/MANIFOLDS/INTAKE MANIFOLD - INSTALLATION)
14. Fill the cooling system. (Refer to - COOLING - STANDARD PROCEDURE)
15. Connect negative cable to battery.