Camshaft, Lifters and Push Rods: Service and Repair

Valve train, servicing

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.
^ Do not rework valve seats. Only lapping-in of valves is permitted.





1. 20 Nm plus an additional 1/4 turn (90°)
^ Always replace
2. Rocker shaft
^ Do not interchange
3. Cylinder head bolt
4. Washer
^ For cylinder head bolts
^ Install into cylinder head before installing bearing caps
5. Hydraulic lifters
^ Do not interchange.
^ With hydraulic valve clearance compensation.
^ Store with cam contact surface downward.
^ Before installing check camshaft axial clearance; Refer to Fig 1.
^ Oil contact surfaces.
^ Before removing, remove camshaft bearing shells
6. Keepers
7. Valve spring plate
8. Exterior valve spring
9. Interior valve spring
10. Valve stem seal
11. Valve guide
^ If wear limit is exceeded, replace cylinder head
12. Unit injector
13. Cylinder head
14. Seal
^ Do not add oil or grease oil seal sealing lip
^ Remove oil residues of camshaft pin with a clean cloth before installing.
15. Valves
^ Replace valve when scoring can be seen at shaft and contact surfaces
^ Do not rework. Only lapping-in is permitted
^ Valve dimensions
16. Bearing shell
^ Do not interchange used bearing shells (mark)
^ Make sure tabs seating correctly in bearing cap and cylinder head
17. Camshaft
^ Checking axial clearance; Refer to Fig 1
^ Check radial clearance with plastigage
Wear limit: 0.11 mm
^ Run-out: max. 0.04 mm
18. Bearing cap
^ Install seal bearing cap contact surfaces 1 and 5 with AMV 174 004 01; Refer to Fig 2
19. 8 Nm plus an additional 1/4 turn (90°)
^ Always replace





Fig. 1 Checking camshaft axial clearance
Special tools and equipment
^ VW387 Universal dial gauge bracket
^ Dial gauge
Measure with hydraulic lifters removed and with first, third and last bearing caps installed.
Wear limit: max. 015 mm





Fig. 2 Sealing bearing cap contact surfaces 1 and 5 with AMV 174 004 01
^ Apply a thin even coat of sealant AMV 17400401 onto surfaces -1-.

Note: Observe that no sealant comes into the grooves (arrows).





Fig. 3 Valve dimensions





Note: Valves must not be reworked. Only lapping-in is permitted.