11 31 505 Adjusting timing of camshaft(s) (N20)

WARNING: This page is about a different variant/trim than selected.

Special tools required:

83 30 2 212 831
11 9 340
00 9 460
83 30 0 496 778
83 30 0 493 971

Necessary preliminary tasks:

Remove CYLINDER HEAD COVER .
Check TIMING .

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

Position tracing gauge (2) on mounting flats of intake camshaft.

Order number:83 30 2 212 831

Fig 1: Locating Intake Camshaft Flats

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

Fig 2: Locating Exhaust Camshaft Cams

The designation E and A on the intake and exhaust camshaft (1) as well as the part numbers can be read from above.

Fig 3: Identifying Camshaft Part Numbers

Secure mounting bridge (1) on cylinder head.

Secure tracing gauges (2 and 3) to mounting bridge (1).

Fig 4: Securing Tracing Gauges To Mounting Bridge

IMPORTANT: The screw connection (5) is imperative for undoing and securing the central bolt.

Secure tracing gauge (2) with screw (5).

Fig 5: Identifying Intake Camshaft Screw Connection

IMPORTANT: The screw connection (7) is imperative for undoing and securing the central bolt.

Screw (6) must be removed for securing the screw (7).

Secure tracing gauge with screw (7).

Fig 6: Identifying Camshaft Screw

IMPORTANT: Only use special tool to undo central bolts (2 and 3) of VANOS units.

If it is not possible to fit special tool, mounting flats of relevant camshaft must be counter-held (risk of damage! ).

Undo central bolts (2 and 3).

Fig 7: Identifying Camshaft Adjusters Central Bolts

Release CHAIN TENSIONER (2).

Tightening torque 11 31 7AZ .

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.

Fig 8: Identifying Chain Tensioner

Installation note:

Replace sealing ring.

Rotate camshaft sensor wheel until retaining pin (1 and 2) match up with setting gauge.

Secure camshaft sensor wheel.

Fig 9: Aligning Retaining Pin With Setting Gauge

Pretension timing chain with special tool 11 9 340 00 9 460 0,6 Nm

Order number:83 30 0 496 778 83 30 0 493 971

Fig 10: Identifying Timing Chain With Special Tool (11 9 340)

Only use special tool to secure central bolt (1) of intake adjuster.

Tightening torque 11 36 1AZ .

Fig 11: Securing Intake Adjuster Central Bolt

Only use special tool to secure central bolt (1) of exhaust camshaft adjuster.

Tightening torque 11 36 1AZ .

Fig 12: Securing Exhaust Camshaft Adjuster Central Bolt

Remove all special tools.

Crank engine on the central bolt twice in the direction of engine rotation and check the TIMING .

Assemble engine.