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

Special tools required:

11 4 281
11 4 481

IMPORTANT: Aluminium-magnesium materials.

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:

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).

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.

Fig 1: Bearing Caps

Courtesy of BMW OF NORTH AMERICA, INC.

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.

Fig 2: Inlet Camshaft And Plain 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 exhaust camshafts are inserted, no joint must point to a separating joint.

Fig 3: Identifying Compression Rings

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 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.

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 intake and exhaust camshafts are different.

Mixing up the intake and exhaust camshaft will result in engine damage.

A Exhaust camshaft.
E intake camshaft

Fig 6: Exhaust Camshaft And Inlet Camshaft
Courtesy of BMW OF NORTH AMERICA, INC.

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.

Fig 7: Inlet Camshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.