Volkswagen Golf/Jetta 2 manual

Cylinder head - dismantling and overhaul
Engine repair procedures - 1.6 and 1.8 litre 8 valve / Cylinder head - dismantling and overhaul


1 Using a wire brush, scraper and steel wool, clean all carbon from the combustion chambers, valve faces and exhaust ports.

Remove the spark plugs for cleaning.

2 The valves are not easy to get out unless a suitable valve spring compressor is available.

Because the collets and spring caps are set so far down in the head, a long claw is necessary on the compressor and it must be split sufficiently to enable the collets to be removed and inserted. If such a tool is not to hand then find a piece of steel tube of about 25 mm inside diameter which will fit over the valve stem and press down the spring cover (see illustration). The length will depend on the size of the compressor so fit the compressor over the head fully extended, measure the distance between the claw and the valve spring seat and cut the tube to a suitable length.

12.2 Improvised tool used to remove and refit collets to valve stems
12.2 Improvised tool used to remove and refit collets to valve stems

3 The next step is to cut two windows of suitable size (approx. 25 mm long and 16 mm wide) in opposite sides of the tube. The tube may then be used with the compressor to extract the collets from each valve stem in turn. Place the valve, springs, collets and seats with the tappet in the appropriate receptacle, keeping them strictly together for refitting in the valve guide from which they were taken (see illustration).

12.3 Valve springs, cap and collets
12.3 Valve springs, cap and collets

4 The valve springs must be renewed if they are damaged, distorted, or known to have covered a high mileage. If in doubt as to their condition, have your VW dealer check them for compression efficiency using a calibrated valve spring compressor.

5 The valves should be cleaned and checked for signs of wear or burring. Where this has occurred, the inlet valve may be reground on a machine at a dealer. Exhaust valves must not be reground on the machine but ground in by hand. On engines fitted with hydraulic tappets, valves should not be re-cut as this will adversely affect the operation of the tappets.

6 Wear in the valve guides may be detected by fitting a new valve in the guide and checking the amount that the rim of the valve will move sideways when the top of the valve stem is flush with the top of the valve guide.

The valve rock limits are given in the Specifications. New valve guides must be fitted and reamed by your VW dealer.

7 Do not spend too long grinding in the valves. If the valve seat and valve are not satisfactory after 15 minutes then you will probably do more harm than good by going on. Make sure both surfaces are clean, smear grinding paste onto the valve evenly and using a suction cup, work the valve with an oscillating motion lifting the valve away from the seat occasionally to stop ridging. Clean the seat and valve frequently and carry on until there is an even grey band on both seat and valve then wipe off all the paste.

8 The surface of the head must be checked with a straight-edge and feeler blade. Place the straight-edge along the centre of the machined face of the head. Make sure there are no ridges at the extreme ends and measure the clearance with feelers between each combustion chamber head. This is the area where the narrowest part of the cylinder head gasket comes and where the gasket is most likely to fail. If the straight-edge is firmly in place and feelers in excess of 0.1 mm can be put between the head and the straight-edge, then the head should be taken to a dealer for servicing or replacement.

9 If the cylinder head shows signs of cracking, have it inspected by your VW dealer to assess its condition for reuse.

10 VW recommend that the valve stem oil seals should always be renewed to prevent possible high oil consumption. Pulling off the old seal is simple with pliers. With a packet of new oil seals is a small plastic sleeve. This is fitted over the valve stem and lubricated. The seal should then be pushed over the plastic sleeve until it seats on the guide. This should be done with VW tool 10 204 which fits snugly round the outside of the seal and pushes it on squarely. If the seal is assembled without the plastic sleeve, it will be damaged and oil consumption will become excessive.

11 Before reassembling the cylinder head, check the condition of the camshaft.

12 When all components have been examined, then assembly of the head may commence. Insert the valve in the correct guide, fit the inner seat, valve springs and outer cap, assemble the valve spring compressor and possibly the small tube and compress the valve spring until the collets may be assembled to the valve stem (see illustrations).

12.12a Inserting a valve into the cylinder head
12.12a Inserting a valve into the cylinder head

12.12b Locating valve springs and cap . . .
12.12b Locating valve springs and cap . . .

12.12c . . . and valve collets
12.12c . . . and valve collets

13 Assemble the second collet and holding them carefully together in place, ease off the compressor until the spring seats the collets home. Remove the compressor, put a rag over the valve stem and tap the stem with a hammer. This is to ensure that the collets are seated correctly. If they are they will not come out. Repeat until all eight valves are in position in the cylinder head.

14 Refit the tappets in the bores from which they came, lubricating them liberally with clean engine oil (see illustration). Lubricate the camshaft bearing surfaces with oil and fit the camshaft, positioned so that No 1 cylinder cams point upwards.

12.14 Fit the tappet buckets
12.14 Fit the tappet buckets

15 Fit a new oil seal at the sprocket end, lubricate the bearings, set the shaft in position and install bearing caps Nos 2 and 4, tightening the nuts in a diagonal pattern until the shaft is in place (see illustration). Now install the other bearing caps, making sure they are the right way round (marks towards the drive pulley) and tighten the caps down using a diagonal pattern to the specified torque. Install a new rubber seal at the opposite end to the sprocket.

12.15 Fit the bearing caps
12.15 Fit the bearing caps

16 On engines equipped with shim bucket tappets, adjust the valve clearances.


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