Valvetrain Component Overview

Valvetrain Component Overview

• Illustration depicts left cylinder head.





1 10 Nm

2 Oil seals

• Replace, refer to => [ Camshaft Seals, Replacing ] Service and Repair

3 Housing

• For camshaft adjustment solenoid valve

4 Gasket

• Replace

5 Exhaust camshaft

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

• Checking axial play, refer to => [ Camshafts, Checking Axial Clearance ] Camshafts, Checking Axial Clearance

• Check using Plastigage (valve lifter removed)

• Radial clearance wear limit 0.1 mm

• Run-out max. 0.01 mm

6 Piston rings for camshaft adjuster

• Equipped with hooks at ends, depending on version

• Hook piston ring ends into each other => [ Piston ring ends, hooking up ]

7 Intake camshaft

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

• Checking axial play, refer to => [ Camshafts, Checking Axial Clearance ] Camshafts, Checking Axial Clearance

• Check using Plastigage (valve lifter removed)

• Radial clearance wear limit 0.1 mm

• Run-out max. 0.01 mm

8 10 Nm

• Tighten in stages from inside to outside

9 Guide frame

• With integrated camshaft bearings

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

10 Cover for Camshaft Position (CMP) Sensor

• Note installation position: Notch in camshaft

11 23 Nm

12 Hydraulic valve lifter

• Checking, refer to => [ Hydraulic Valve Lifters, Checking ] Testing and Inspection

• Removing and installing, refer to => [ Valve Stem Seals, Replacing ] Service and Repair

• Do not interchange

• Place on running surface when setting down

• Before installing, check axial play of camshafts, refer to => [ Camshafts, Checking Axial Clearance ] Camshafts, Checking Axial Clearance

• Lubricate contact surface

13 Valve cotters

14 Valve spring plate

15 Valve spring

16 Valve stem seal

• Replace, refer to => [ Valve Stem Seals, Replacing ] Service and Repair

17 Intake camshaft position sensor

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

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

18 10 Nm

19 Exhaust camshaft position sensor

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

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

20 O-ring

• Replace

21 10 Nm

22 Camshaft position sensor housing

23 Gasket

• Replace

24 Cylinder head

• See note, refer to => [ Valvetrain ] Valvetrain

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

• Rework valve seats, refer to => [ Valve Seats, Reworking ] Service and Repair

25 Intake valve

• Do not rework, only lapping is permitted

• Mark installation position for re-installation

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

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

26 Exhaust valve

• Do not rework, only lapping is permitted

• Mark installation position for re-installation

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

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

Piston ring ends, hooking up





• Depending on version, piston rings at camshaft adjusters are equipped with hooks on ends.

• On this version, piston ring ends must be hooked into each other.

- If necessary, hook up ends of installed piston rings - arrows - as shown in the illustration.