Installing Cylinder Head

Installing and tightening the cylinder head





Note: The cylinder head may be mounted with the engine installed.

1. Place the cylinder head gasket in the correct position.

2. Mount cylinder head

Model 87 Onward
Engine type M44.40
Tightening sequence:
1st stage 20 Nm
2nd stage 90° torque angle
3rd stage 90° torque angle

Model 89 Onward
Engine type M44.41 (3.0L)

Note: The cylinder head has been reinforced by 20 mm in the area of the bearing surfaces for the cylinder head nuts. This has altered the tightening sequence.

Tightening sequence:
1st stage 20 Nm
2nd stage 60° torque angle
3rd stage 90° torque angle

Note: Never use lubricant when fitting cylinder head nuts and washers. Apply a light film of engine oil to the stud thread only.

Installing Camshafts

1. Turn engine in direction of rotation by approx. 45° before ignition TDC (cylinder 1).

2. Lay intake shaft and exhaust camshaft in the timing chain.

3. Place both camshafts in the timing chain so that the cast lugs are aligned with the marked links of the chain. Oil the bearing journals and place in the bearings carefully together with the timing chain.





Note: The distance between the marking on the intake camshaft and the marking on the exhaust camshaft amounts to 7 outer chain links; the distance between the cast lugs measures approx. 113 mm.





4. Fasten the camshafts to the cylinder head with assembly bridges Special Tool 9248 together with the clamping bolt of Special Tool 9226.









5. Install the bearing bridges and bearing cover of the camshaft. The bearing bridges and cover are production-matched to the cylinder head and must always be installed as a set. Note the identification code and pairing number.
Tightening torque for bearing bridges and cover 20 Nm.

6. Apply Loctite 574 to the sealing surfaces of the front and rear double bearing bridges.





7. Use the assembly drift, Special Tool 9233 and pressure piece 9234 to drive the sealing ring into position at the drive end of the camshaft.Lubricate the sealing lip before assembly.

Note: The timing chain must always be replaced if the valves have been damaged by the piston as a result of a broken toothed belt. A thorough visual inspection must be made of the sprockets and chain tensioner.

8. Install Chain Tensioner.

9. Install and adjust toothed timing belt. Service and Repair

10. Reassemble rest of engine.