Camshaft: Adjustments

11 31 505 Adjusting camshaft timing (N14)

Special tools required:







IMPORTANT:
Modified procedure for timing adjustment.
The timing is not determined at firing TDC of cylinder no. 1
All pistons are in the 90° position.
Check locking of adjustment units.
To open the central bolt at the camshaft, grip hexagon on rear of camshaft.
Risk of damage.







Necessary preliminary tasks:
- Remove cylinder head cover.







IMPORTANT:
Danger of mixing up special tool bore.
Balance hole and special tool bore can be mixed up; all pistons must be in the 90° position.
If necessary, determine by means of spark plug bore.

Rotate crankshaft at central bolt.
Slide in special tool 11 9 590 in direction of arrow and block crankshaft.







IMPORTANT:
Risk of damage to chain drive.
To open central bolt, mount special tool 11 9 551 on camshaft.
If the setting gauges cannot be positioned, grip the camshaft with an open-end wrench to release the central bolt.







Release chain tensioner (have a cleaning cloth ready).
Tightening torque: 11 31 4AZ.







To open central bolts (3), mount special tool 11 9 551 on camshafts.
Release central bolts (3).
Tightening torque: 11 36 2AZ.







To open central bolts (3), mount special tool 11 9 551 on camshafts.
Release central bolts (3).
Tightening torque: 11 36 1AZ.







The designations for the inlet camshaft (IN) and exhaust camshaft (EX) point upwards.
Both camshafts (inlet and exhaust) have three machined surfaces to enable special tool 11 9 551 to be mounted.
The fourth surface is not machined and is crescent-shaped - it must point downwards.

NOTE: Picture shows







Position of exhaust camshaft (1) points at an angle to the right in a lower inward direction.

NOTE: Picture shows sprocket wheel removed.







Position of inlet camshaft (1) points at an angle to the left in an upper inward direction.

NOTE: Picture shows VANOS adjustment unit removed.







Screw special tool 11 9 340 into cylinder head.
Pretension timing chain with special tool 00 9 250 to 0.6 Nm.







Secure central bolt (1) with special tool 00 9 120 or an electronic torque wrench.
Tightening torque: 11 36 1AZ.







Secure central bolt (1) with special tool 00 9 120 or an electronic torque wrench.
Tightening torque: 11 36 2AZ.







Remove all special tools.
Assemble engine.