Valvetrain Assembly Overview

Valvetrain Assembly Overview

Note:
^ The cylinder head and the cylinder head cover must be replaced together.
^ After installing the camshafts, the engine may not be started for approximately 30 minutes. The hydraulic adjusting elements must seat themselves (otherwise the valves will seat themselves on the pistons).
^ After working on the valvetrain and lifters, carefully rotate the crankshaft by hand at least 2 full revolutions before starting to be sure that valves do not strike the pistons.
^ Always replace gaskets and seals.





1. Exhaust Valve
^ Do not rework, only lapping is permitted
2. Cylinder Head
3. Valve Guide
4. Valve Stem Seal
5. Valve Spring
6. Valve Spring Plate
7. Valve Keepers
8. Hydraulic Valve Play Balancing Element
^ Do not interchange
^ Lubricate contact surface
9. Exhaust Camshaft
^ Check radial clearance using Plastigage (roller rocker lever removed)
^ Radial clearance at bearing-dia. 24 mm: 0.024 to 0.066 mm
^ Radial clearance at bearing-dia. 32 mm: 0.030 to 0.051 mm
^ Run-out: max. 0.04 mm
10. Cylinder Head Cover
^ With integrated camshaft bearings
^ Clean sealing surface, reworking is not permitted.
^ Remove old sealant residue.
11. Bolt
^ Replace
12. O-Ring
^ Replace
^ Coat with engine oil
13. Sealing Plugs
14. Intake Camshaft
^ Check radial clearance using Plastigage (roller rocker lever removed)
^ Radial clearance at bearing-dia. 24 mm: 0.024 to 0.066 mm
^ Run-out: max. 0.04 mm
15. Sealing Cap
^ Replace
^ Removing: With the cylinder head cover installed, pierce through one side of the cover with an awl and pry it out
^ Installing: Without sealant, press in 1 to 2 mm using the thrust piece 3334
16. Intake Valve
^ Do not rework, only lapping is permitted





Cylinder Head Cover Tightening Sequence
- Replace bolts
- Hand-tighten bolts in several stages in - 1 to 6 - sequence.
- Tighten bolts in a - 1 to 6 - sequence to 8 Nm using a torque wrench.
- Tighten bolts an additional 90 degree using a rigid wrench in the sequence - 1 to 6 -.

Note:
^ Ensure guide frame is not tilted.