Camshaft: Adjustments

11 31 505 - Adjusting camshaft timing (N12)

Special tools required:
- 00 9 120 00 9 120 Torque Angle Measuring Dial
- 00 9 250
- 11 9 340 11 9 340 Device
- 11 9 450
- 11 9 540 11 9 540 Gauge
- 11 9 590 11 9 590 Mandrel
- 32 2 100

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.

Observe direction of engine rotation (direction of rotation always clockwise when viewed towards timing drive side).

To open the central bolt at the camshaft, grip hexagon on rear of camshaft.

Risk of damage!

Necessary preliminary tasks:
- Remove cylinder head cover Service and Repair.
- Check timing Testing and Inspection.

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 open central bolt, mount special tool 11 9 540 11 9 540 Gauge 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. Mechanical Specifications

To open central bolts (1 and 2), mount special tool 11 9 540 11 9 540 Gauge on camshafts.

Release central bolts (1 and 2).

Tightening torque:11 36 1AZ 11 36 Variable Camshaft Control VANOS.

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 9 450 to be mounted.

The fourth surface is not machined and is crescent-shaped - it must point downwards.

Position of exhaust camshaft (EX) points at an angle to the right in an upper outward direction.

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

Rotate exhaust camshaft with special tool 32 2 100 in direction of arrow.

Pretension camshaft with special tool 32 2 100.

Attach special tool 11 9 540 11 9 540 Gauge (exhaust side) to dihedron and secure with bolt (1).

Attach special tool 11 9 540 11 9 540 Gauge (inlet side) to dihedron and secure with bolts (1 and 2).

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 11 36 Variable Camshaft Control VANOS.

Remove all special tools.

Assemble engine.