Valvetrain, Component Overview

Valvetrain, Component Overview





1 - Exhaust valve

^ Different versions
^ Do not rework, only lapping is permitted
^ Mark installed position for re-installation
^ Valve dimensions
^ Check valve guides

2 - Sealing plug

^ Install with sealant

3 - Cylinder Head

^ Check valve guides

4 - Hydraulic adjusting element

^ Checking
^ Do not interchange
^ Lubricate contact surface

5 - Securing clip

^ Check for secure seat

6 - Intake camshaft

^ Checking axial play
^ 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. 36 mm: 0.032 to 0.078 mm
^ Run-out: max. 0.04 mm

7 - Bearing bracket

^ With integrated camshaft bearings

8 - 8 Nm plus an additional 90 degree (1/4 turn)

^ Replace

9 - Exhaust camshaft

^ Checking axial play
^ 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. 36 mm: 0.032 to 0.078 mm
^ Run-out: max. 0.04 mm

10 - Roller rocker lever

^ Do not interchange
^ Check roller for easy movement
^ Lubricate contact surface
^ To assemble, clip onto hydraulic adjusting element -4- using a circlip -5-

11 - Valve keys

12 - Valve spring plate

13 - Valve spring

^ Installation position: The tight spring coils face toward cylinder head

14 - Valve stem seal

^ Replacing, Cylinder Head Installed
^ Replacing, Cylinder Head Removed

15 - Intake valve

^ Do not rework, only lapping is permitted
^ Mark installed position for re-installation
^ Valve dimensions
^ Check valve guides