Opel Corsa B 1993–2000 Service and Repair Manual: Cylinder head - removal and refitting

Note: The procedure described here is the removal of the cylinder head leaving the inlet manifold and fuel injection equipment in place. If preferred, the manifold can be removed with the head after making the appropriate disconnections.

Removal

1. Remove the camshaft toothed belt.

2. Disconnect the multi-plug from the air mass meter. Undo the four or five Allen screws, release the idle speed adjuster hose and remove the volume chamber and air mass meter together.

3. Drain the cooling system by disconnecting the radiator bottom hose.

4. Disconnect the accelerator cable.

5. Remove the nine nuts which secure the inlet manifold. They have deformed threads so they are stiff. A socket with a universal joint or 'wobble drive' will be needed to reach some of the nuts.

6. Cut the cable-tie which secures the injector wiring harness to the cylinder head.

7. Disconnect the two small breather hoses from the camshaft cover (see illustration).

Disconnecting the small breather hoses from the camshaft cover

8. Unbolt the support bracket from the base of the inlet manifold (see illustration). Slide the manifold off the cylinder head studs. Be careful not to strain the fuel hoses or the wiring.

Unbolting the inlet manifold support bracket (seen from below)

9. Remove the exhaust manifold.

10. Remove the radiator top hose.

11. Disconnect the heater hose from below the distributor (see illustration).

Disconnecting the heater hose from the cylinder head

12. Remove the spark plug lead cover secured by two Allen screws. Disconnect the HT leads from the plugs and move them aside.

13. Remove the distributor.

14. Remove the thermostat housing.

15. Disconnect the large breather hose from the camshaft cover (see illustration). Unbolt the hose bracket from the cylinder head.

Disconnecting the large breather hose

16. Remove the 20 Allen screws which secure the camshaft cover (see illustration). Remove the cover.

Removing a camshaft cover screw

17. Remove the camshaft sprockets.

18. Remove the two Torx screws which secure the top of the belt backplate to the cylinder head. Also remove the rubber bush and unscrew the belt cover mounting stud (see illustrations).

Remove the rubber bush . . .

. . . and the belt cover mounting stud

19. Using a size E12 Torx socket, slacken the cylinder head bolts a quarter-turn each in the sequence shown. In the same sequence slacken the bolts a further half-turn, then undo them completely and remove them (see illustrations). Recover the washers. New bolts must be used when refitting.

Cylinder head bolt slackening sequence

Removing a cylinder head bolt and washer

20. Lift off the cylinder head, pulling the inlet manifold back towards the bulkhead slightly if necessary (see illustration). Be careful not to bend the belt backplate. Put the head down on two blocks of wood so that it does not rest on the protruding valves.

Lifting off the cylinder head

21. Recover the gasket from the cylinder block and clean the mating surface, being careful not to get any debris into the cylinder bores. Cover the open bores, or stuff oily rags into them, to protect them if the head is going to be off for more than a few hours.

Refitting

22. Commence refitting by placing a new head gasket onto the block, making sure that it fits over the locating dowels and that it is the right way up (see illustration). It is marked 'OBEN/TOP'.

New head gasket in position

23. Lower the head onto the block and fit it onto the dowels. Fit the washers to the new bolts, fit the bolts and tighten them finger tight.

24. Following the sequence shown, tighten the bolts through the first four stages given in the Specifications (see illustrations).

Cylinder head bolt tightening sequence

Removing a tappet. Note the oil ring (arrowed)

25. The remainder of refitting is a reversal of the removal procedure, noting the following points:

1. Use new gaskets on the thermostat housing, the manifolds and the camshaft cover (see illustration).
2. Use a new camshaft toothed belt and tension.
3. Tighten all fastenings to the specified torque.
4. Run the engine until the cooling fan cuts in. If the hydraulic tappets have been disturbed, they may be noisy for a few minutes until they settle down. Switch the engine off, remove the camshaft cover again and tighten the cylinder head bolts through the final specified stage.

Fitting a new gasket to the camshaft cover