Installing Cylinder Head

WM 157023 Installing cylinder head





Information

Component overview





Component overview

1 - Cap
2 - Cylinder head
3 - Straight pin
4 - Pan-head screw M12 x 1.5 x 140
5 - Cap
6 - Spark plug
7 - Cap
8 - Cylinder-head gasket
9 - Vent connection

Installing cylinder head

Installing cylinder head

Caution:
Leaks due to components being at too low a temperature or at different temperatures!
If components that are cold or at different temperatures are sealed together by the application of sealant, adhesion problems and leaks can arise due to the build-up of condensation water or component distortion.

- Components must have reached at least 17°C throughout.

- Components must not be too hot (distortion).

- Spare parts that are stored in the cold or heat (strong sunlight), must be brought to room temperature or the same temperature as other parts before installation.





Mechanical angle disc for torque angle screws

Information:
All sealing surfaces must be clean and free of grease!
It is essential to work carefully!
Tightening sequences and tightening torques must be observed!
If more extensive work, such as complete replacement of the cylinder head, is necessary, the exhaust manifolds must be modified as well.

1. Place cylinder head gasket correctly, i.e. according to the specifications, onto the straight pins of the engine crank housing. This must be done in such a way that the "Top" marking can be read -figure-.





Cylinder bank 1 - 4





Cylinder bank 5 - 8

2. Fit cylinder head. Insert M12 x 1.5 x 140 cylinder head screws (screws can be used again).
3. The tightening sequence 1-10 must be observed for every tightening step.

Setting torque

- Tightening torque: 22 ftlb.

- Tightening torque: 37 ftlb.

Undo all cheese-head bolts.

Final tightening torque:

- Tightening torque: 22 ftlb.

- Tightening torque: 22 ftlb.

- torque angle: 90°





Tightening sequence for cylinder head fastening screws

Information:
In the case of the turbocharged engine (M48/50), screw down the upper fastening screws of the turbocharger.





Turbocharger fastening screws

4. Fasten primary catalytic converter to the exhaust manifold. To do this, fasten three fastening nuts. - Tightening torque: 17 ftlb.





Fastening nuts for exhaust manifold

5. Secure cable of starter catalyst oxygen sensor in the cable guide.
6. Place vent line on the cylinder head flange. To do this, press the ribbed surfaces of the buttons and pull off the plugs.





Vent line on connection piece of cylinder head

7. Mount oil separator vent line onto cylinder head with new sealing ring -2-. To do this, position and tighten the fastening screws -3 and upper 4-. - Tightening torque: 7.5 ftlb.





Oil separator vent line

8. Fasten guide rail of timing chain -3-. To do this, tighten the fastening screws -4-. - Initial tightening: 11 ftlb. - Final tightening: 90°





Timing chain guide rail

1 - Camshaft timing gear
2 - M12 x 140 cheese-head bolt
3 - Guide rails
4 - Guide rail fastening screw
5 - Timing chain; use same running direction when reusing

Subsequent work

Subsequent work

1. Install camshaft housing.
2. Install chain case lid.
3. Install intake-air distributor.
4. Install cover for camshaft housing.
5. Install engine.