11 31 025 Removing and installing/replacing inlet camshaft (N52K)

Special tools required:

IMPORTANT: Aluminium-magnesium materials.
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 .
Jointing torque and angle of rotation must be observed without fail (risk of damage) .

Necessary preliminary tasks:

Remove cylinder head cover
Remove inlet adjustment unit
Remove INTERMEDIATE LEVER
Adjust VALVE TIMING

NOTE: All bearing caps (1 and 2) are marked with numbers from 1 to 6.

Bearing cap (1) is a thrust bearing.

Release screws on bearing caps 1 to 6 (1 and 2).

Tightening torque 11 31 2AZ .

Set all bearing caps down in special tool 11 4 481 in a tidy and orderly fashion.

Fig 1: Identifying Bearing Cap

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Remove inlet camshaft (2) towards top.

Installation:

Clean all bearing points and lubricate with oil.

Fig 2: Identifying Inlet Camshaft And Compression Rings

Courtesy of BMW OF NORTH AMERICA, INC.

Metal plain rectangular compression ring:

IMPORTANT: Plain rectangular compression rings (1) can easily break.

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.

Fig 3: Identifying Compression Ring

Courtesy of BMW OF NORTH AMERICA, INC.

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.

Fig 4: Installing Plastic Plain Rectangular Compression Ring

Courtesy of BMW OF NORTH AMERICA, INC.

Check plastic plain rectangular compression ring (1 and 2) for freedom of movement.

Fig 5: Checking Ring For Freedom Of Movement

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IMPORTANT: Markings of inlet and exhaust camshafts are different.
Mixing up the inlet and exhaust camshaft will result in engine damage.
A = Exhaust camshaft.
E = Inlet camshaft

Fig 6: Identifying Exhaust Camshaft And Inlet Camshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Insert inlet camshaft (1) so that part number on twin surface points upwards.

Position inlet camshaft (1) so that cams point upwards at an angle.

Attach special tool 11 4 281 to twin surface.

Fig 7: Identifying Inlet Camshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.