Timing Chain Tensioner

Valve gear, servicing

Note:
- Cylinder heads which have cracks between the valve seats or between valve seat inserts and the spark plug thread can be used further without reducing service life, the cracks do not exceed a maximum of 0.3 mm in width, or when no more than the first 4 turns of the spark plug threads are cracked.
- After installing new lifters the engine must not be started for about 30 minutes (otherwise valves will strike pistons). Turn crankshaft two complete revolutions before starting.
- Carefully apply a small amount of sealant D 454 300 A2 at the four end points of the sealing surfaces on the cylinder head, using a small screwdriver, Refer to Fig. 1.





1. Double bearing cap
- Lightly coat with sealant 454 300 A2 before installing.
2. Exhaust camshaft bearing cap
- With connection for oil feed pipe
- Watch position of dowel sleeve
- Note installation position and numbering
- Lightly coat last bearing cap (after the chain) with sealant D 454 300 A2 before installing
3. 10 Nm
4. Exhaust camshaft
- Checking axial clearance, Camshaft Axial Clearance, Checking
- Removing and installing, Service and Repair
- Check radial clearance with Plastigage (lifters removed) Wear limit: 0.1 mm Run-out: 0.01 mm (maximum)
5. Cap
- Always replace
6. Inlet camshaft bearing cap
- With connection for oil feed pipe
- Note installation position and numbering Service and Repair
7. Inlet camshaft
- Checking axial clearance, Camshaft Axial Clearance, Checking
- Removing and installing, Service and Repair
- Check radial clearance with Plastigage (lifters removed) Wear limit: 0.1 mm Run-out: 0.01 mm (maximum)
8. Drive chain
- Installing, Service and Repair
9. 10 Nm
10. Mechanical - camshaft adjuster
- With camshaft adjustment valve -N205
- Secure with special tool 3366 before removing, Service and Repair
11. Hydraulic bucket lifter
- Removing and installing with cylinder head installed, Service and Repair
12. Valve cotters
13. Valve spring plate
14. Valve spring
15. Valve stem seal
- Replacing with cylinder head installed, Service and Repair
16. Rubber/metal - gasket
- Always replace
17. Seal
- Always replace
18. Cylinder head
- Checking for distortion, Testing and Inspection
- Reworking, Cylinder Head, Reworking
19. Exhaust valve
20. Inlet valve
21. Oil seal (Hall sender end)
- Always replace, Service and Repair
22. Rotor for Hall sender
- Note position (notch on camshaft)
23. Washer
- Conical
24. 25 Nm
25. Hall sender
26. 10 Nm
27. 30 Nm +180 (1/2 turn)
28. Camshaft sprocket
29. Oil seal (toothed belt end)
- Replacing, Service and Repair




Fig. 1 Sealing end points of joints between bearing caps and cylinder head
- Carefully apply small quantity of sealant D 454 300 A2 at four end points of sealing surfaces on cylinder head -arrows-, using a small screwdriver.