Valve: Service and Repair

Note:
^ Cylinder heads with cracks between the valve seats may be used without reducing engine life, provided the cracks are small and not more than 0.5 mm wide.
^ After installation of new hydraulic lifters do not start the engine for 30 minutes. Turn the crankshaft over twice by hand. Otherwise valves will touch pistons.





1. Bearing cap
^ Installation positron
^ Installation sequence
^ Coat bearing cap 1 lightly with sealant AMV 1 74 004 01.
2. 20 Nm (15 ft. lbs.)
3. Camshaft
^ Axial clearance, checking see Fig. 1
^ Removing and installing
^ Check radial clearance with plastigage
^ Wear limit: 0.11 mm
^ Runout: max. 0.01 mm
^ Identification and valve timing see Fig. 4
4. Hydraulic lifter
^ Do not interchange
^ Checking
^ Store with cam contact surface facing downward
^ Lubricate contact faces with oil
^ Before installing, check camshaft axial clearance see Fig. 1
5. Keepers
6. Upper valve spring plate
7. Valve spring
^ Removing: with cylinder head removed, use 2037
^ Replacing valve stem seals
8. Valve stem seal
^ Replacing
9. Valve guide
^ Checking
^ Replacing
^ Service version with collar
10. Oil seal
^ To remove and install, remove bearing cap
^ Toothed belt, removing and installing
11. Cylinder head
^ Valve seats, reworking
12. Valves
^ Do not machine valves, only lapping is permissible.
^ Valve dimensions see Fig. 3





Fig. 1 Camshaft axial clearance, checking
Special tools
^ VW 387 Universal dial gauge bracket
^ Dial gauge

Note: Check with hydraulic lifters removed and with first and last bearing caps installed.

^ Wear limit: max. 0.15 mm





Fig. 2 Camshaft bearing caps, installed position
Note offset. Before installing camshaft, trial install bearing caps and determine correct position.





Fig. 3 Valve dimensions





Note: Valves must not be machined. Only lapping is permitted.





Fig. 4 Camshaft identification, valve timing
Identification
^ Cam base diameter: a = 38 mm





^ Camshaft is identified by stamped numbers and letters between intake and exhaust cams:








^ Valve timing at 1 mm valve lift