Removing and Installing/Replacing Inlet Camshaft

11 31 025 - Removing and installing or replacing inlet camshaft (N54)





Special tools required:
- 00 9 120 00 9 120 Torque Angle Measuring Dial
- 11 4 350 11 4 350 Torque Wrench
- 11 8 550 11 8 550 Device
- 11 8 551
- 11 8 552
- 11 8 553
- 11 9 000 11 9 000 Device





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 banks must be tensioned with a total of six special tools 11 8 553.

Special tool 11 8 550 can be used for inlet and exhaust sides.





Necessary preliminary tasks:
- Remove cylinder head cover
- Remove inlet adjustment unit of inlet camshaft





Release bearing cap screw connections from outside inwards.

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

Note:
Illustration shows N52.





Remove upper bearing shell.

Remove inlet 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 - Inlet camshaft





Check plain compression rings (1) for damage and replace if necessary.

Plain compression rings (1) are engaged at joint.

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

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





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 profile insert.





Installing camshaft bearing bank:

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.

E = - Inlet side
A = - Exhaust side
Press down roller cam follower on cylinder no. 3 with spindle nut (2) of special tool 11 8 551.





Installation Note:
Before installing inlet camshaft, make sure roller cam follower is correctly seated on HVCA element and valve.





Installation Note:
Pre-install bearing strip of inlet camshaft.

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

Installation Note:
Lay inlet camshaft (1) in bearing strip.





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





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

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





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

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





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

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





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

Important!
Tighten screws on thrust piece to 2 Nm.





Important!
Set special tool 11 4 350 to 2 Nm.

Pretension 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 inlet camshaft with bearing banks (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 banks with special tool 00 9 120.

Tightening torque 11 31 1AZ. Specifications

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





Adjust valve timing.

Assemble engine.