Cylinder head - dismantling and overhaul

Engine repair procedures - 1.05 and 1.3 litre post August 1985 / Cylinder head - dismantling and overhaul

Caution: If new tappets are fitted, the engine must not be started after fitting for approximately 30 minutes, or the valves will strike the pistons.

Cylinder head
1 If the valve seats are badly pitted or eroded they can be reworked but this is a specialist job best left to a VW dealer or engine overhaul specialist.

2 Similarly, if the head is warped, its surfaces can be skimmed, again by specialist engineers.

3 If it is found that there are cracks from the valve seats or valve seat inserts to the spark plug threads, the cylinder head may still be serviceable. Consult your VW dealer for advice.

Hydraulic bucket tappets 4 With the camshaft removed, lift out the tappets one by one, ensuring that they are kept in their correct order and can be returned to their original bores (see illustration).

5.4 Removing an hydraulic bucket tappet

5 Place them, cam contact surface down, on a clean sheet of paper as they are removed.

6 Inspect the tappets for wear (indicated by ridging on the clean surface), pitting and cracks.

7 Tappets cannot be repaired and if worn, must be renewed.

8 Before fitting the tappets, lubricate all parts liberally with clean engine oil and slip each tappet back into its original bore.

Valves
9 With the camshaft and tappets removed, use a valve spring compressor with a deep reach to compress the valve springs. Remove the two cotters and release the compressor and springs.

10 Lift out the upper spring seat (see illustration).

5.10 Removing valve spring upper seat

11 Remove the outer and inner valve springs (see illustrations).

5.11a Removing an outer valve spring

5.11b Removing an inner valve spring

12 Lift out the valve (see illustration).

5.12 Removing a valve

13 The valves should be inspected as described in Part A of this Chapter, Section 11.

14 Valves must be renewed if they are worn and be ground in the normal manner.

15 If possible, check the valve spring lengths against new ones. Renew the whole set if any are too short.

16 Refitting is a reversal of removal.

Valve stem oil seals
17 The valve stem oil seals should be renewed whenever the valves are removed, by prising them from the ends of the valve guides (see illustration).

5.17 A valve stem oil seal

18 With the seals removed, the lower spring seats can also be lifted out for cleaning. Press the new seals onto the ends of the valve guides.