11 31 025 Removing and installing/replacing intake camshaft (N52K)
- 11 4 281
- 11 4 481
No steel screws/bolts may be used due to the threat of electrochemical corrosion.
A magnesium crankcase requires aluminium screws/bolts exclusively.
Aluminium screws/bolts must be replaced each time they are released .
Aluminium screws/bolts are permitted with and without color coding (blue).
For reliable identification:
Aluminium screws/bolts are not magnetic .
Jointing torque and angle of rotation must be observed without fail (risk of damage).
Necessary preliminary tasks:
- Remove Cylinder Head Cover
- Remove Intake Adjustment Unit
- Remove Intermediate Lever
- Adjust Valve Timing.
Bearing cap (1) is a thrust bearing.
Release screws on bearing caps 1 to 6 (1 and 2).
For tightening torque refer to 11 31 2AZ in 11 31 CAMSHAFT .
Set all bearing caps down in special tool 11 4 481 in a tidy and orderly fashion.
Remove intake camshaft (2) towards top.
Installation:
Clean all bearing points and lubricate with oil.
Check plain 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 exhaust 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 rectangular compression ring (1) into groove of exhaust camshaft (2) (see arrow in Fig 4). Lightly oil plastic rectangular compression ring (1) and rotate in direction of arrow until compression ring (1) is positioned on the exhaust 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 twin surface 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.