Camshaft: Adjustments

11 31 505 Adjusting Timing Of Camshaft(s) (N55)

Special tools required:







IMPORTANT:
For the positioning of the special tool 11 4 281 on the mounting flats of the intake camshaft, a collision with the cylinder throttle return spring 1 can occur.
Rework special tool 11 4 281 on the basis of the following description.







Necessary preliminary tasks:
- Remove cylinder head cover.
- Check timing.







With 1st cylinder in TDC firing position, cams of intake camshaft (1) at 1st cylinder point upwards at an angle.







With 1st cylinder in TDC firing position, cams of the exhaust camshaft (1) point upwards at an angle.







Part numbers (2) on intake and exhaust camshafts (1) point upwards.







Secure special tool 11 4 285 with bolts (1) to cylinder head.

NOTE: Fit special tool 11 4 282 underneath on side of intake camshaft.

Mount reworked special tool 11 4 281 on the intake camshaft.
Mount special tool 11 4 281 on the exhaust camshaft.







IMPORTANT: Only use special tool 11 4 280to loosen central bolts (1 and 2) of VANOS unit.

Release central bolts (1 and 2).







Release chain tensioner (1).
Tightening torque 11 31 6AZ.

IMPORTANT:
Have a cleaning cloth ready. A small quantity of engine oil will emerge after the screw connection has been released.
Make sure no engine oil runs onto belt drive.

Installation note:
Replace sealing ring.







Turn increment wheel (2) in direction of arrow until retaining pins (1) on special tool 11 4 290 match up.
11 4 290Slide on special tool in direction of arrow.







Use bolts to fasten special tool 11 4 290.

Installation note:
Replace both central bolts.
Screw in both central bolts.
Release both central bolts 90°.

11 9 340Screw special tool into cylinder head.







Pretension timing chain with special tool 11 9 340 00 9 250 0,6 Nm







Use special tool 00 9 120 to tighten central bolts of intake adjuster.
Tightening torque 11 36 1AZ.







Use special tool 00 9 120 to tighten central bolts of exhaust camshaft adjuster.
Tightening torque 11 36 1AZ.







Remove all special tools.
Crank engine on the central bolt twice in the direction of engine rotation and check the timing.
Assemble engine.