Cylinder Head and Cover Overview

Cylinder Head and Cover Overview

• If a replacement cylinder head is installed, several contact surfaces between the support elements, roller rockers and cam lubricating surfaces of the camshaft must be lubricated before installing the cylinder head cover.

• The plastic protectors installed to protect the open valves must only be removed immediately before installing the cylinder head.

• Replace the cylinder head bolts.

• When replacing the cylinder head or cylinder head gasket, the coolant must be completely replaced.






1 Bolt

• 10 Nm

2 Cylinder Head Cover

• With the pressure regulator valve for the crankshaft housing ventilation.

• Tightening sequence, refer to => [ Tightening Sequence for the Cylinder
Head Cover Bolts ].

• Removing and installing, refer to => [ Cylinder Head Cover ] Cylinder Head Cover.

3 Cylinder Head Cover Gasket

• Replace if damaged or leaking.

4 Crankcase Ventilation Hose

• To the intake manifold.

5 Oil Filler Cap

6 Gasket

• Replace if damaged or leaking.

7 Bolt

• 10 Nm

8 Wire Bracket

9 Seal

• Removing and installing, refer to => [ Chain Compartment Cover Seal ] Service and Repair.

10 Wire Bracket

11 Chain Compartment Cover

• Removing and installing, refer to => [ Chain Compartment Cover ] Chain Compartment Cover.

12 Bolt

• 2 Nm

13 Camshaft Adjustment Valve 1 (N205)

• Check using the vehicle diagnosis, testing and information system VAS 5051.

14 O-ring

• Replace if damaged.

• For the camshaft position sensor => [ (Item 16) ] no replacement part.

15 Bolt

• 10 Nm

16 Camshaft Position Sensor (G40)

17 Transport Strap

18 Bolt

• 25 Nm

19 Cylinder Head Gasket

• Always replace.

• After replacing, replace the entire amount of coolant.

20 Cylinder Head

• Removing and installing, refer to => [ Cylinder Head ] Cylinder Head.

• Checking the cylinder head for warpage, refer to => [ Checking the Cylinder Head for Distortion ].

• It is not permitted to rework the sealing surface.

• With the coolant pipe connection pressed in.

- If necessary, remove coolant deposits using a copper wire brush or fine sandpaper (minimum 100 grit).

- If the pipe connection is worn, replace it using liquid locking fluid (D 000 600 A2).

21 Cap

• On engines without a Secondary Air Injection (AIR) system only.

• Engines with a AIR system, refer to => [ Secondary Air Injection System Overview ] Service and Repair.

22 Gasket

• Always replace.

23 Bolt

• 40 Nm + 180° (1/2) additional turn.

• Always replace.

• Follow the loosening/tightening sequence. Refer to => [ Cylinder Head ] Cylinder Head.

24 Wire Bracket

• For the heated oxygen sensor (G39).

Tightening Sequence for the Cylinder Head Cover Bolts





Checking the Cylinder Head for Distortion





- Check the cylinder head at multiple points for distortion, using a straight edge and feeler gauges.

• Maximum permissible distortion: 0.05 mm

If this value is exceeded, the cylinder head must be replaced. It is not permissible to rework the sealing surface.