Cylinder Head Overview

Cylinder Head Overview






1 Bolt

• 10 Nm

2 Cylinder Head Cover

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

• Tightening sequence, refer to => [ Cylinder Head Cover Bolt Tightening Sequence ].

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

3 Cylinder Head Cover Gasket

• Replace if damaged or leaking.

4 Crankcase Ventilation Hose

• To the intake manifold.

5 Cap

6 Gasket

• Replace if damaged or leaking.

7 Bolt

• 10 Nm

8 Wire Bracket

9 Seal

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

10 Wire Bracket

11 Timing Chain Cover

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

12 Bolt

• 2 Nm

13 Camshaft Adjustment Valve 1 (N205)

• Check using the vehicle diagnostic tester.

14 O-ring

• Replace if damaged.

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 any coolant deposits with a brass wire brush or with a fine sandpaper (minimum 100 grit).

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

21 Cap

• Only on engines with Secondary Air Injection (AIR).

• AIR system overview. Refer to => [ Secondary Air Injection System Overview ] Service and Repair.

22 Gasket

• Always replace.

23 Bolt

• 40 Nm + an additional 180° (1/2) additional turn.

• Always replace.

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

24 Wire Bracket

• For the heated oxygen sensor (G39).

Cylinder Head Cover Bolt Tightening Sequence





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.