Valve Gear, Servicing

Overview

Note:

- Cylinder heads with cracks between the valve seats or between a valve seat and the spark plug thread can continue to be used without reducing service life, as long as the cracks have a width of max. 0.5 mm.






1. Nut: Tighten to 5 Nm + 1/8 turn (45 °) additional
2. Exhaust camshaft bearing cap
3. Seal
- If leaking, replace as complete unit
- Lightly oil sealing rings when installing control housing
- Do not spread sealing rings excessively when inserting
4. Exhaust camshaft
- Check radial play using Plastigage
- Wear limit: 0.1 mm
- Max. runout: max. 0.01 mm
5. Control housing
- Lightly oil contact surface of sealing ring before installing
6. Crankshaft roller chain
- Mark direction of travel (installation position) before removing.
7. Exhaust camshaft adjuster
- Identification: 32A
- Only rotate engine with crankshaft adjuster installed
8. Bolt, Tighten to 60 Nm + 1/4 turn (90 °)
- Always replace camshaft adjuster bolts.
- Contact surface of chain sprocket at bolt head must be dry when installing.
- To remove and install, counterhold at crankshaft using an open-end spanner (32 mm). Service and Repair
9. Intake Camshaft adjuster
- Identification: 24E
- Only rotate engine with crankshaft adjuster installed
10. Cylinder head height
- Minimum height: a = 139.9 mm
11. Valves
- Do not reface. Only handlapping is permitted.
12. Cylinder head
- Check for warpage.
- After replacing, completely replace coolant
13. Support element
- Do not interchange
- With hydraulic play adjuster
14. Valve stem oil seal
15. Locking clamp
- Check for Secure fitting
16. Roller cam follower
- Do not interchange
- Check for ease of movement
- Oil contact surface
- To install, clip onto support element with locking clamp
17. Valve spring
- Note installed position
18. Valve spring retainer
19. Valve keepers
20. Intake camshaft bearing cap
- Check radial play using Plastigage Wear limit: 0.1 mm
- Max. runout: max. 0.01 mm
21. Intake camshaft
- Check radial play using Plastigage Wear limit: 0.1 mm
- Max. runout: max. 0.01 mm