Cylinder Head Assembly: Service and Repair

CAUTION: Never stand the cylinder head on its flanges as open valves will protrude. Stand the cylinder head on wooden blocks.





NOTE: For work on the cylinder head, use the Cylinder Head Bracket - 78 60 794 (available as a special tool) for mounting the cylinder head on the engine stand.





Removal, Engine In Car:
1. Remove the bonnet.
2. Remove the battery.
3. Drain the coolant from the radiator and block.
4. Remove the exhaust manifold and turbo unit.
5. Remove the tensioning pulley and drive belt for the AC compressor.
6. Slacken the securing bolts for the steering servo pump bracket, remove the drive belt and push the pump out of the way.
7. Release the wiring loom from the clips on the cylinder head. If the cylinder is to be mounted on the floor stand, remove the clips.





8. Remove the two bolts in the timing cover, which are screwed into the cylinder head from underneath.
9. Remove the RH engine mounting bolts screwed into the cylinder head, together with the spacer sleeves.
10. Disconnect the coolant hose from the thermostat housing.
11. Remove the fuel pressure regulator.
12. Disconnect the earth connections for the LH fuel injection system.
13. Remove the auxiliary air valve (N/A to cars with catalytic converter).
14. Unbolt the A/C bracket from the cylinder head.
15. Remove the inlet manifold complete with injection valves and fuel injection manifold.
16. Disconnect the lead from the temperature sensor.
17. Remove the inspection plate on the valve cover, and the HT leads complete with distributor cap.
18. Remove the valve cover. Disconnect the crankcase ventilation hose and remove the split rubber plugs from the cylinder head.
19. Line up the timing marks on the crankshaft and camshafts.
20. Remove the chain tensioner.

CAUTION: Do not alter the setting of the camshaft or crankshaft after the sprockets have been removed, as rotation of one of the shafts can result in damage to the valves.

Camshaft Sprocket Bolts:

21. Remove the camshaft sprockets.
22. Block up the engine to lift the cylinder head off the engine steady bar. Remove the cylinder head bolts and siphon off the oil from the cylinder head.









23. Install a guide pin in one of the bolt holes and lift off the cylinder head, taking care to ensure that the pivoting and fixed guides for the timing chain are not damaged. Refit the drain plug in the block and close the drain valve on the radiator.

Fig. 4 Cylinder Head Bolt Tightening Sequence:

24. Reverse procedure to install, noting the following:
a. On cylinder heads with 17 mm bolts, torque cylinder head bolts in sequence shown in Fig. 4, first to 44 ft. lbs., then to 70 ft. lbs. Warm engine to operating temperature, then allow engine to cool for 30 minutes and loosen all cylinder head bolts, then retorque bolts in sequence shown in Fig. 4, to 70 ft. lbs., then an additional 90°.
b. On cylinder heads with 15 mm or Torx bolts, Torque cylinder head bolts in sequence shown in Fig. 4, first to 44 ft. lbs., then to 59 ft. lbs., then an additional 90°.
c. Install two bolts on underside of head and torque to 14.5 ft lbs.
d. Install camshaft sprocket for exhaust valve camshaft first. Ensure chain between camshaft and crankshaft sprockets is tight, then install camshaft sprocket for inlet valve camshaft.
e. Adjust chain tension with camshaft sprocket center bolts not fully tightened. Tighten tensioner bolt, then release tensioner by pressing pivoting guide firmly against it. Depress pivoting guide to verify proper tensioner operation, then rotate engine two complete turns. Ensure crankshaft and camshafts are still properly aligned, then tighten sprocket bolts to specifications.