Removing and Installing/Replacing Inlet Camshaft

11 31 025 Removing and installing/replacing intake camshaft (N54 / N54T)

Special tools required:






Important!
Risk of damage!
It is absolutely essential to follow an exact procedure for removing and installing the exhaust camshaft.
The upper and lower bearing strips must be pre-tensioned with a total of six special tools 11 8 553.
Special tool 11 8 550 can be used for intake and exhaust sides.






Necessary preliminary tasks:
- Remove cylinder head cover
- Remove intake adjuster of intake camshaft






Release bearing cap screw connections from outside inwards.

Lift out lower and upper bearing strips (1) with camshaft.

Note:
Graphic shows N52.






Remove upper bearing shell.

Remove intake camshaft (1) marked with (E).






Important!
Both camshafts have different markings.
Mixing up the two camshafts will result in engine damage.
A Exhaust camshaft
E Intake camshaft






Important!
Plain rectangular compression rings (1) can easily break.

Plain rectangular compression rings (1) are engaged at joint.

Press plain compression rings (1) apart upwards and downwards and removed towards front.






Important!
Removal on engine:
Engine at cylinder no. 1 firing TDC position.
Removed cylinder head:
When using special tool 11 9 000, it will be necessary to remove the aluminium strip.






Installing camshaft bearing strip:

Pre-install special tool 11 8 551 on cylinder nos. 2 and 3.

Insert special tool 11 8 552 in screw connection of cylinder head cover.

Special tool 11 8 551 is marked with letters E and A.

Press down roller cam follower on cylinder no. 3 with spindle nut (2) of special tool 11 8 551.

E= Intake side

A= Exhaust side






Installation note:
Before installing intake camshaft, make sure roller cam follower is correctly seated on hydraulic valve clearance compensating element and valve.






Installation note:
Pre-install bearing strip of intake camshaft.

Lubricate all bearing points in lower bearing strip with engine oil.

Installation note:
Lay intake camshaft (1) in bearing strip.






Rotate intake camshaft (1) at cylinder no. 1 into position (2).






Installation note:
Lower and upper bearing strips must be aligned to each other at ground surfaces (1 and 2).

Bring thrust piece and legs of special tools 11 8 553 into contact at milled surfaces.






Note:
Schematic depiction of special tool 11 8 553 at lower bearing strip (1) and upper bearing strip (2).

Important!
Tighten screw (3) on thrust piece to 2 Nm.






Position special tool 11 8 553 over screw connection of bearing strips.

Make sure that legs come into exact contact on ground surfaces, lower bearing strip (1) and upper bearing strip (2).






Initially tighten screw of special tool 11 8 553 to ground surfaces of lower bearing strip (1) and upper bearing strip (2).

Important!
Tighten screws on thrust piece to 2 Nm.






Important!
Set special tool 11 4 350 to 2 Nm.
Pre-tension all special tools 11 8 553 with special tool 11 4 350 only.






Install upper and lower bearing strips (1).

Pre-install all special tools 11 8 553.

Important!
Secure special tool 11 8 553 to max. 2 Nm.






Install intake camshaft with bearing strips (1) on cylinder head.






Check position of intake camshaft (1) at cylinder no. 6.

Roller cam follower (2) is not actuated.






Tighten lower and upper bearing strips with special tool 00 9 120.

Tightening torque 11 31 1AZ.

Important!
Remove special tool 11 8 553 only when camshaft screw connection is completed.






Adjust valve timing.

Assemble engine.