Camshaft, Lifters and Push Rods: Service and Repair

Valvetrain Assembly Overview

• 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 the valves do not strike the pistons.

• Always replace gaskets and seals.





1 Exhaust Valve

• Do not rework, only lapping is permitted

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

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

2 Cylinder Head

3 Valve Guide

• Checking, refer to --> [ Valve Guides, Checking ] Testing and Inspection.

4 Valve Stem Seal

• Replacing, refer to --> [ Valve Stem Seals, Cylinder Head Installed ] Service and Repair.

5 Valve Spring

6 Valve Spring Plate

7 Valve Retainers

8 Hydraulic Adjusting Element

• Do not interchange.

• Lubricate the contact surface

9 Exhaust Camshaft

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

• Checking axial play, refer to --> [ Camshafts, Axial Clearance Checking ] Testing and Inspection.

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

• Radial clearance at 24 mm diameter bearing: 0.024 to 0.066 mm.

• Radial clearance at 32 mm diameter bearing: 0.030 to 0.051 mm.

• Run out: Max. 0.04 mm.

10 Cylinder Head Cover

• With integrated camshaft bearings.

• Clean the sealing surface, reworking is not permitted.

• Remove the old sealant residue.

11 Bolt

• Always replace.

12 O-ring

• Always replace.

• Lubricate with engine oil.

13 Sealing Plug

14 Intake Camshaft

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

• Checking axial play, refer to --> [ Camshafts, Axial Clearance Checking ] Testing and Inspection.

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

• Radial clearance at 24 mm diameter bearing: 0.024 to 0.066 mm.

• Run out: Max. 0.04 mm.

15 Cap

• Always 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 (T10174).

16 Intake Valve

• Do not rework, only lapping is permitted.

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

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

Cylinder Head Cover Bolt Tightening Sequence and Specification





Special tools, testers and auxiliary items required

• Torque wrench 5-50 Nm (VAG 1331)

- Tighten the new cylinder head cover bolts in 3 passes in sequence - 1 through 6 - as follows:

- Tighten the bolts by hand.

- Tighten the bolts to 8 Nm.

- Tighten the bolts an additional 90° (1/ 4 turn).

• Ensure the cylinder head cover is not tilted.