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

Removal

1. Remove the camshaft toothed belt as described in Section 7.

2. Remove the spark plug cover, which is retained by two Allen screws. Disconnect the breather hoses from the camshaft cover, remove the 20 Allen screws and the camshaft cover itself.

3. Hold a camshaft using an open-ended spanner on the flats provided towards the sprocket end. Without allowing the camshaft to move (risk of piston-to-valve contact) slacken the sprocket bolt. Remove the bolt, washer and sprocket (see illustrations).

Removing a camshaft sprocket bolt and washer

Removing a camshaft sprocket

4. Repeat the operation on the other camshaft. Although both sprockets appear to be identical, it is good practice not to get them mixed up. The exhaust sprocket on the engine shown here is marked 'L'; the inlet sprocket is unmarked (see illustration).

Exhaust camshaft sprocket is marked 'L'

5. Remove the distributor.

6. Check that the camshaft bearing caps carry identification numbers, and note which way round they are fitted. The inlet camshaft caps are numbered 1 to 5, the exhaust camshaft caps 6 to 10. Corresponding numbers are cast in the cylinder head (see illustration).

Matching numbers on bearing cap and cylinder head

7. Progressively slacken the bearing cap nuts, half a turn at a time until the valve spring pressure has been released. Do not overlook the two extra nuts on the cap which forms part of the distributor housing (see illustration). Remove the nuts and washers and lift off the caps. Be careful that a camshaft does not spring up suddenly when removing the caps.

Distributor housing bearing cap has two extra nuts

8. Remove the camshafts with their oil seals.

Be careful when handling them, as the edges of the lobes are sharp. Remove the oil seals.

Refitting

9. Commence refitting by generously oiling the camshaft bearing surfaces and lobes. If fitting new camshafts, apply the special assembly lubricant provided.

10. Apply sealant to the mating faces of the bearing caps which house the oil seals (Nos 1 and 6) and to the one which houses the distributor drive (No 11).

11. Place the camshafts in position with the sprocket locating pins uppermost. Fit the bearing caps, in their correct positions and the right way round, and the nuts and washers (see illustration).

Fitting a camshaft bearing cap

12. Tighten the bearing cap nuts half a turn at a time in progressive sequence so the camshafts are pulled down evenly. Finally tighten them to the specified torque (see illustration).

Tightening a camshaft bearing cap

13. Fit new oil seals.

14. Refit the sprockets to their respective camshafts. Fit the sprocket bolts and tighten them to the specified torque, holding the camshafts with a spanner on the flats to prevent rotation (see illustration).

Tightening a camshaft sprocket bolt

15. Using a strap wrench on the sprocket or a spanner on the sprocket bolt, carefully move each camshaft a little way to verify that it is free to turn. If the cylinder head is installed on the engine, be careful that piston-to-valve contact does not occur. If a camshaft will not turn, it may be that the bearing caps have been fitted the wrong way round.

16. Refit the distributor and the camshaft cover.

17. Fit a new camshaft toothed belt.

18. If new camshafts have been fitted, it is suggested that the running-in schedule specified, be observed.