Camshaft, Lifters and Push Rods: Service and Repair

Valvetrain Assembly Overview





1 Bolt, 50 Nm + 180° (1/2) additional turn

• Use the retainer (3036) to loosen and tighten.

• Always replace.

2 Camshaft Gear

• Use the retainer (3036) to loosen and tighten.

3 Seal

• Replacing, refer to => [ Exhaust Camshaft Seal ] Service and Repair.

4 Cylinder Head

• Do not regrind the valve seats, only lapping with a grinding compound is permitted.

5 Valve Guide

• Checking, Refer to => [ Valve Guides, Checking ] Testing and Inspection.

6 Valve Stem Seal

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

7 Valve Spring

8 Top Valve Spring Retainer

9 Valve Retainers

10 Hydraulic Valve Play Balancing Element

• Do not interchange.

• Lubricate the contact surface.

11 Fitted Key

• Check for secure seating.

12 Exhaust camshaft

• Check radial clearance using Plastigage (roller rocker lever removed).

• Wear limit: 0.1 mm.

• Runout: Max. 0.035 mm.

13 Guide Frame

• With integrated camshaft bearings.

• Clean sealing surface, reworking is not permitted.

• Remove old sealant residue.

14 Bolt, 8 Nm + 90° (1/4) additional turn

• Always replace.

15 Camshaft Adjuster

• Removing and installing, refer to => [ Camshaft Adjuster ] Camshaft Adjuster.

16 Bolt, 20 Nm + 45° (1/8) additional turn

• Use the retainer (3036) to loosen and tighten.

17 Intake Camshaft

• Check radial clearance with Plastigage.

• Wear limit: 0.1 mm.

• Runout: Max. 0.035 mm.

18 Chain Tensioner

• Secure using the locking pin (T10115) before removing.

19 Drive Chain

• Removing and installing, refer to => [ Camshaft Adjuster ] Camshaft Adjuster.

• Check for wear.

20 Bolt, 10 Nm

21 Bolt, 10 Nm

22 Camshaft Position (CMP) Sensor (G40)

23 Exhaust Valve

• Do not grind, only lapping is permitted.

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

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

24 Intake Valve

• Do not grind, only lapping is permitted.

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

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

25 Cap

• Always replace.

• Removing: Insert a screwdriver into the center of the cap and pry out.

• Installing: Do not use sealant, press in 1 to 2 mm using thrust piece (3334).