Cylinder Head, Servicing

Check compression.

Note:
- Use only the assembly tool T10029 for connecting and disconnecting the spark plug connector.
- When installing a replacement cylinder head with installed camshafts, the contact areas between the valve lifter and the cam track must be oiled after installing the head.
- The supplied plastic open valve protectors should only be removed immediately before mounting the cylinder head.
- When replacing the cylinder head, all of the coolant must be replaced.

1. Intake manifold upper
- First, tighten at lower half of manifold, then tighten at both supports
2. Retainer
- For fuel lines
3. Throttle with control unit (J338)
- May not be opened
- With throttle acceleration (G186)
- With angle transmitter 1- for throttle acceleration (G187)
- With angle transmitter (2) for throttle acceleration (G188)
- Heated by coolant
4. 10 Nm
5. Profile gasket
6. Gasket cover
- Replace gasket if damaged
7. Cylinder head cover
- Replace if damaged or leaking
- Coat with D 454 300 A3 before placing the connections cover/cylinder head and the half moon shaped recess
8. Gasket for cylinder head cover
- Replace if damaged
- Note installation position
9. 25 Nm
10. Coolant return pump (V51)
11. Retainer
12. Cylinder head
- Check for distortion see Fig. 1
- After replacing, replace all of the coolant
13. O-Ring
- Always replace
14. Chain - tensioner, 40 Nm
- For camshaft roller chain
- Turn engine only with installed chain tensioner
15. Seal ring
- Always replace
16. Cover
- Can be removed and installed with the cylinder head installed
- Coat sealing surfaces with AMV 188 001 02
- If only the cover has been removed, prepare the cylinder head gasket for installation Fig. 2
17. Ignition coil (N152)
18. Cylinder head gasket
- Always replace
- After replacing, replace all of the coolant
- Metal gasket
19. Thermostat housing
20. Seal
- Always replace
21. Combination - valve
22. Seal upper intake manifold
- Replace if damaged
23. Intake manifold lower
24. Seal lower intake manifold
- Replace if damaged
25. Tensioner
- For V-ribbed drive belts
26. Cylinder head screw
- Always replace
- Note assembly instructions and order when loosening or tightening
27. Vacuum actuator
- For switching of intake manifold runner





Fig. 1 Checking cylinder head for distortion
Special tools, equipment, test and inspection devices; required accessories
- Feeler gauge

Max. allowable distortion: 0.1 mm





Fig. 2 Preparing cylinder head gasket for installation
Special tools, equipment, test and inspection devices; required accessories
- Sealant AMV 188 001 02
- Clean 3 mm bores in cylinder head gasket or cover and sealing flange of old sealant -arrows-.
- Fill 3 mm bore in cylinder head gasket with sealant AMV 188 001 02 and coat sealing surfaces on cover and sealing flange with sealant.

Note: With the cylinder head installed, the bores in the cylinder head gasket are only partially visible.