Camshaft: Adjustments

11 31 505 - Adjusting camshaft timing (M52TU/M54/M56)





Special tools required:
- 00 9 250 00 9 250 Torque Wrench with Flexible Extension
- 11 2 300 11 2 300 Plug Mandrel
- 11 3 240 11 3 240 Locking Fixture
- 11 3 244 11 3 240 Locking Fixture
- 11 3 292
- 11 4 220 11 4 220 Chain Tensioner
- 11 5 180 11 5 180 Plug Mandrel, Angled
- 11 6 150 11 6 150 Adjusting Plate

(refer to Operation No. 11 31 005)

Before carrying out adjustment work:

Check camshaft timing Testing and Inspection.





Crank engine in direction of rotation until cam tips on inlet and exhaust camshafts on 1st cylinder face one another.





Secure crankshaft with special tool 11 2 300 11 2 300 Plug Mandrel in TDC position of 1st cylinder.

X3 only:

Secure crankshaft with special tool 11 5 180 in TDC position of 1st cylinder.

Important!
Do not turn the engine back.

Remove special tools 11 2 300 11 2 300 Plug Mandrel / 11 5 180 11 5 180 Plug Mandrel, Angled before starting engine.





Unscrew studs.





Remove double VANOS adjustment unit Service and Repair.





Press down top of chain tensioner and lock off with special tool 11 3 292.





Important!
Cylinder for chain tensioning piston is under spring pressure.

Remove cylinder for chain tensioning piston.





Install special tool 11 4 220 11 4 220 Chain Tensioner.

Fit adjusting screw to bow cover.





Release screws (1) by half a turn.





Release nuts (2) by two turns.

Release nuts (3) by one turn.





Important!
Toothed shaft (4) slips very easily from splines.

Pull out toothed shaft (4) until approx. 1 mm of splines can be seen.





Withdraw toothed shaft (5) up to stop.





Fit special tool 11 3 240 11 3 240 Locking Fixture to camshafts on cylinder 6. Align camshafts so that special tool 11 3 240 11 3 240 Locking Fixture rests without gaps on cylinder head.





Attach special tool 11 3 244 11 3 240 Locking Fixture to special tool 11 3 240 11 3 240 Locking Fixture and locate by way of spark plug thread.





Press down chain tensioner at top and remove special tool 11 3 292.





Preload tensioning rail with special tool 11 4 220 11 4 220 Chain Tensioner by rotating adjusting screw with special tool 00 9 250 00 9 250 Torque Wrench with Flexible Extension or standard torque wrench to 0.7 Nm.





Preload cup spring slightly by pressing on sensor gear (1) and tighten nuts by hand.

Important!
Do not tighten down nuts fully.





Remove gasket.

Check dowel sleeves (1) for damage and correct installation position.

Keep sealing face clean and free of oil.





Important!
Fit special tool 11 6 150 11 6 150 Adjusting Plate "without gasket" only.

If gasket remains underneath special tool 11 6 150 11 6 150 Adjusting Plate, camshaft timing will be "incorrectly" set.

Attach special tool 11 6 150 11 6 150 Adjusting Plate "without gasket", tighten nuts by hand and then tighten down uniformly until special tool 11 6 150 11 6 150 Adjusting Plate is in full contact with cylinder head.





Insert screws (1) on exhaust side and initially tighten to approx. 5 Nm.





Initially tighten nuts (2) on exhaust side and nuts (3) on inlet side to approx. 5 Nm.





Tighten down screws (1) on exhaust side.

Tightening torque 11 31 3AZ 11 31 Camshaft.





Tighten down nuts (2) on exhaust side and nuts (3) on inlet side.

Tightening torque 11 31 11AZ 11 31 Camshaft.





Pull special tool 11 2 300 11 2 300 Plug Mandrel / 11 5 180 11 5 180 Plug Mandrel, Angled back until flywheel is no longer secured.





Remove special tool 11 3 244 11 3 240 Locking Fixture and special tool 11 3 240 11 3 240 Locking Fixture.





Crank engine twice in direction of rotation until cam tips on inlet and exhaust camshafts on 1st cylinder face one another.





Secure crankshaft in firing TDC position with special tool 11 2 300 11 2 300 Plug Mandrel.

X3 only:

Secure crankshaft with special tool 11 5 180 11 5 180 Plug Mandrel, Angled in TDC position of 1st cylinder.

Important!
Do not turn the engine back.

Remove special tools 11 2 300 11 2 300 Plug Mandrel / 11 5 180 11 5 180 Plug Mandrel, Angled before starting engine.





Fit special tool 11 3 240 11 3 240 Locking Fixture to camshafts.





Note:
The timing is correctly set if the special tool 11 3 240 11 3 240 Locking Fixture rests without a gap on the cylinder head or protrudes up to 1 mm to the inlet side.

The timing must be reset if the special tool 11 3 240 11 3 240 Locking Fixture protrudes to the exhaust side.





Unfasten and remove special tool 11 4 220 11 4 220 Chain Tensioner.





Install cylinder for chain tensioning piston Service and Repair.





Remove special tool 11 2 300 11 2 300 Plug Mandrel / 11 5 180 11 5 180 Plug Mandrel, Angled.





Remove special tool 11 6 150 11 6 150 Adjusting Plate.

Install VANOS adjustment unit Service and Repair.

Assemble engine.