Valvetrain Component Overview

Valvetrain Assembly Overview

• Cylinder head for cylinder bank 2 (left) is shown in illustration.





1 Sealing plug

2 Valve stem seal

• Replacing with the cylinder head installed, refer to => [ Valve Stem Seals, Cylinder Head Installed ] Valve Stem Seals, Cylinder Head Installed

• Replacing with the cylinder head removed, refer to => [ Valve Stem Seals with Cylinder Head Removed ] Valve Stem Seals With Cylinder Head Removed

3 Valve spring

• Installed location, refer to => [ Installed Position of Valve Spring ]

4 Hydraulic adjusting element

• Clipped into roller rocker lever - item 8 -

• Checking, refer to => [ Hydraulic Adjusting Elements, Checking ] Testing and Inspection

• Do not interchange

• Lubricate contact surface

5 Valve spring plate

6 Valve keepers

7 Securing clip

• Check for secure seat

8 Roller rocker lever

• Do not interchange

• Check roller for easy movement

• Lubricate contact surface

• To assemble, clip onto the hydraulic adjusting element - item 4 - using a circlip - item 7 -

9 Intake camshaft

• Removing and installing, refer to => [ Camshafts ] Service and Repair

• Measuring axial play, refer to => [ Camshaft, Measuring Axial Play ] Camshaft, Measuring Axial Play

• Radial clearance, measuring, refer to => [ Camshaft, Measuring Radial Play ] Camshaft, Measuring Radial Play

• Run-out: max. 0.04 mm

10 Gasket

• Replace

11 Bearing bracket

• With integrated camshaft bearings

• Removing and installing, refer to => [ Camshafts ] Service and Repair

12 8 Nm

• Observe tightening sequence, refer to => [ Camshafts ] Service and Repair

13 Camshaft position sensor, intake camshaft

• Cylinder bank 1 (right) Camshaft Position (CMP) Sensor (G40)

• Cylinder bank 2 (left) Camshaft Position (CMP) Sensor 2 (G163)

14 9 Nm

15 O-ring

• Replace

16 9 Nm

17 Camshaft position sensor, exhaust camshaft

• Cylinder bank 1 (right) Camshaft Position (CMP) Sensor 3 (G300)

• Cylinder bank 2 (left) Camshaft Position (CMP) Sensor 4 (G301)

18 O-ring

• Replace

19 Compression ring

• For camshaft adjuster

20 Exhaust camshaft

• Removing and installing, refer to => [ Camshafts ] Service and Repair

• Measuring axial play, refer to => [ Camshaft, Measuring Axial Play ] Camshaft, Measuring Axial Play

• Radial clearance, measuring, refer to => [ Camshaft, Measuring Radial Play ] Camshaft, Measuring Radial Play

• Run-out: max. 0.04 mm

21 Cylinder Head

• Check valve guides, refer to => [ Valve Guides, Checking ] Testing and Inspection

22 Intake valve

• Do not rework, only lapping is permitted

• Mark installed position for re-installation

• Valve dimensions, refer to => [ Valve Dimensions ] [1][2]Specifications

• Check valve guides, refer to => [ Valve Guides, Checking ] Testing and Inspection

23 Exhaust valve

• Do not rework, only lapping is permitted

• Mark installed position for re-installation

• Valve dimensions, refer to => [ Valve Dimensions ] [1][2]Specifications

• Check valve guides, refer to => [ Valve Guides, Checking ] Testing and Inspection

Installed Position of Valve Spring





• The tight spring coils - arrow - face toward cylinder head.