Cylinder Head Assembly: Service and Repair

CYLINDER HEAD

REMOVAL
1. Disconnect the battery negative cable.
2. Drain cooling system.
3. Remove the air cleaner resonator and duct work.
4. Remove the generator.
5. Remove closed crankcase ventilation system.
6. Disconnect the evaporation control system.
7. Perform the Fuel System Pressure Release procedure. Disconnect the fuel supply line.
8. Disconnect heater hoses.
9. Remove cylinder head covers and gaskets.
10. Remove intake manifold and throttle body as an assembly.
11. Remove rocker arm assemblies and push rods. Identify to ensure installation in original locations.
12. Remove the head bolts from each cylinder head and remove cylinder heads. Discard the cylinder head gasket.

CLEANING
Clean all surfaces of cylinder block and cylinder heads.
Clean cylinder block front and rear gasket surfaces using a suitable solvent.

INSPECTION
1. Inspect the cylinder head for out-of-flatness, using a straightedge and a feeler gauge. If tolerances exceed 0.0508 mm (0.002 in.) replace the cylinder head.
2. Inspect the valve seats for damage. Service the valve seats as necessary.
3. Inspect the valve guides for wear, cracks or looseness. If either condition exist, replace the cylinder head.
4. Inspect pushrods. Replace worn or bent pushrods.

INSTALLATION
1. Clean all surfaces of cylinder block and cylinder heads.
2. Clean cylinder block front and rear gasket surfaces using a suitable solvent.

CAUTION: The head gaskets are not interchangeable between left and right sides. They are marked "L" and "R" to indicate left and right sides.

3. Position new cylinder head gaskets onto the cylinder block.

CAUTION: The head gaskets are marked "TOP" to indicate which side goes up.

4. Position cylinder heads onto head gaskets and cylinder block.





5. Tighten the cylinder head bolts in three steps (Fig. 4):
- Step 1-Snug tighten M12 cylinder head bolts, in sequence, to 34 Nm (25 ft. lbs.) and M8 bolts to 20 Nm (15 ft. lbs.) torque.
- Step 2- Tighten M 12 cylinder head bolts, in sequence, to 54 Nm (40 ft. lbs.) and verify M8 bolts to 20 Nm (15 ft. lbs.) torque.
- Step 3- Turn M 12 cylinder head bolts, in sequence, 90 degrees and tighten M8 bolts to 34 Nm (25 ft. lbs.) torque. Fig. 4 CYLINDER HEAD TIGHTENING SEQUENCE
6. Install push rods and rocker arm assemblies in their original position.
7. Install the intake manifold and throttle body assembly.
8. If required, adjust spark plugs to specifications. Install the plugs.
9. Connect the heater hoses.
10. Install the fuel supply line.
11. Install the generator and drive belt.
12. Install cylinder head covers.
13. Connect the evaporation control system.
14. Install the air cleaner.
15. Fill cooling system.
16. Connect the negative cable to the battery.
17. Start engine check for leaks.