Valve Gear, Servicing
CAUTION!
- DO NOT re-use fasteners that are worn or deformed in normal use.
- Some fasteners are designed to be used only once and are unreliable and may fail the second time. Always replace these fasteners with new parts were indicated and any other time when deemed necessary by inspection.
CAUTION! After working on valves, do not start the engine for about 30 minutes, otherwise valves will strike pistons. Turn the crankshaft two complete revolutions by hand before starting engine.
Note: Cylinder heads with cracks between valve seats or between valve seat inserts and spark plug threads can continue to be used without reduced service life, if the cracks are not wider than 0.3 mm (0.012 inch) or when no more than 4 turns of the spark plug threads are cracked.
1. Double bearing cap
- Lightly coat with sealant AMV 1 88 02, Refer to Fig. 2
2. 10 Nm (7 ft. lbs.)
3. Hydraulic valve lifter
^ Removing and installing.
^ Do not interchange.
^ Lubricate contact surface with oil.
4. Exhaust camshaft
^ Check axial play
^ Removing and installing.
^ Check radial clearance using Plastigage (lever removed):
^ Wear limit: 0.1 mm (0.0039 inch)
^ Maximum runout: 0.01 mm (0.0004 inch)
5. Intake camshaft bearing cap
^ Note installation position and numbering
^ Observe dowel pin.
6. Exhaust camshaft bearing cap
^ Observe dowel pin.
^ Note installation position and numbering
7. 10 Nm (7 ft. lbs.)
8. Double bearing cap
9. Cap
^ Always replace
^ To remove: remove bearing cap.
^ With cap installed, lightly drive in with 3202
10. Bearing cap
^ Before installing, lightly coat with sealer AMV 188 02, Refer to Fig. 2
CAUTION! Part numbers are listed for reference only. Always check with your Parts department for latest information.
11. Valve roller lever for exhaust camshaft
12. Drive chain
13. Valve roller lever for intake camshaft
14. Intake camshaft
^ Check axial play
^ Removing and installing
^ Check radial clearance using Plastigage (lever removed):
^ Wear limit: 0.1 mm (0.0039 inch)
^ Maximum run-out: 0.01 mm (0.0004 inch)
15. 10 Nm (7 ft. lbs.)
16. Mechanical camshaft adjuster
^ With valve for camshaft adjustment -N205
^ Before removing, secure with 3366 bracket tensioner
17. Rubber/metal
^ seal
^ Always replace.
18. Valve keepers
19. Valve spring plate
20. Valve spring
21. Valve stem seal
^ Replacing.
22. Seal
^ Always replace.
23. Cylinder head
^ See note.
^ Valve guides, checking.
^ Valve seats, reworking.
24. Exhaust valve
^ Do not rework, only lapping is permitted
^ Valve dimensions, Refer to Fig. 1.
^ Valve guides, checking, valve seats lapping.
25. Intake valve
^ Do not rework, only lapping is permitted
^ Valve dimensions, Fig. 3
^ Valve guides, checking, valve seats lapping.
26. Seal
^ For intake camshaft
^ Removing and installing.
27 - 28 Rotor for Camshaft Position (CMP) sensor
^ Note position
29. Washer
^ Conical 30 - 23 Nm (17 ft. lbs.)
31. Camshaft Position (CMP) sensor
32. 5 Nm (44 inch lbs.) + 90°
33. Shaft for valve roller lever, intake side
34. 9 Nm (80 inch lbs.)
35. 9 Nm (80 inch lbs.)
36. Shaft for valve roller lever, exhaust side
37. 55 Nm (41 ft. lbs.)
38. Camshaft sprocket
39. Seal
^ For exhaust camshaft
^ Removing and installing.
Fig. 1 Valve dimensions
Note: Do not reface valves. Only hand-lapping is permissible
(Part 1 Of 2):
(Part 2 Of 2:
WARNING! Sodium-filled exhaust valves must not be scrapped until they have been properly treated as follows:
- Saw valves in two between center of valve stem and valve head. Do not put water on valves at this point.
- Put valves into bucket of water (not more than 10 at a timed and step back. A sudden chemical reaction will occur during which sodium filling burns. After this treatment the valves can be scrapped normally.
Fig. 2 Bearing cap, applying sealer
- Coat grey surfaces of front and rear bearing caps for intake camshaft lightly with sealant AMV 188 02. Install bearing caps, observe dowel pins.
CAUTION! Part numbers are listed for reference only. Always check with your Parts department for the latest information.