11 31 025 Removing and installing/replacing intake camshaft (N52)
Special tools required:
No steel screws/bolts may be used due to the threat of electrochemical corrosion.
A magnesium crankcase requires aluminum screws/bolts exclusively.
Aluminum screws/bolts must be replaced each time they are released .
Aluminum screws/bolts are permitted with and without color coding (blue).
For reliable identification:
Aluminum screws/bolts are not magnetic .
Joining torque and angle of rotation must be observed without fail (risk of damage) .
Necessary preliminary tasks:
- Remove CYLINDER HEAD COVER .
- Check TIMING .
- Remove INTAKE CAMSHAFT ADJUSTER .
- Remove INTERMEDIATE LEVERS .
Bearing cap (1) is a thrust bearing.
Release bearing cap (1).
Release screws on bearing caps (2) 1 to 6.
Tightening torque 11 31 9AZ .
Set all bearing caps down in special tool 11 4 481 in a neat and orderly fashion.
Remove intake camshaft (2) towards top.
Installation note:
Clean all bearing positions and lubricate with oil.
Check plain rectangular compression rings (1) for damage and replace if necessary.
Metal plain rectangular compression ring:
Only replace plain rectangular compression rings (1) when they are broken.
The plain rectangular compression rings have catches at the joint.
Press plain rectangular compression rings (1) apart upwards and downwards and removed towards front.
Make sure plain rectangular compression rings (1) can move freely.
Installation note:
When intake camshafts are inserted, no joint must point to a separating joint.
Plastic plain rectangular compression ring:
Installation note:
The plastic plain rectangular compression ring is maintenance free and does not have to be replaced.
Insert plastic plain rectangular compression ring (1) into groove of intake camshaft (2) (see arrow).
Lightly oil plastic plain rectangular compression ring (1) and rotate in direction of arrow until plastic plain rectangular compression ring (1) is positioned on the intake camshaft.
Check plastic plain rectangular compression ring (1 and 2) for freedom of movement.
Mixing up the intake and exhaust camshaft will result in engine damage .
A Exhaust camshaft.
E Intake camshaft
Insert intake camshaft (1) so that part number on mounting flats points upwards.
Position intake camshaft (1) so that cams point upwards at an angle.
Attach special tool 11 4 281 to mounting flats.
Assemble engine.