Removal

Removal of the VANOS adjustment unit and the VANOS gear is described separately from installation. The assembly sequence for removal and installation is different.

When the engine is switched off, VANOS moves the camshafts to a position which is advantageous to engine starting.

Caution: Before the VANOS adjustment unit is removed, the camshafts on cylinder bank 5 to 8 must be rotated back to their initial position.





Rotate crankshaft in direction of rotation as far as ignition TDC position of cylinder 1. Secure vibration damper with special tool 11 2 300.





Cylinder bank 5 to 8:
Remove oil line from VANOS adjustment unit.





Cylinder bank 5 to 8:
Fit special tool 11 7 130 to VANOS adjustment unit.
Connect compressed air (2 to 8 bar).





Cylinder bank 5 to 8:
Disconnect plug connection for solenoid valves on cylinder bank 5 to 8.
Connect special tool 12 6 050 in conjunction with special tool 12 6 411 (from special tool kit 12 6 410) to solenoid valves on cylinder bank 5 to 8. Connect special tool 12 6 411 to correct terminals on car battery.
Alternately press toggle switch buttons 4 and 3 several times on special tool 12 6 050.





Caution: Do not damage the cylinder head.

If necessary, machine open-end wrench accordingly.





Cylinder bank 5 to 8:
Press and hold down toggle switch button 4 on special tool 12 6 050.
Simultaneously rotate inlet camshaft at hexagon against direction of rotation up to stop.

Note: The splines in the VANOS gear are now in contact; the inlet camshaft cannot be rotated further.





Cylinder bank 5 to 8:
Alternately press toggle switch buttons 2 and 1 several times on special tool 12 6 050.





Cylinder bank 5 to 8:
Press and hold down toggle switch button 2 on special tool 12 6 050.
Simultaneously rotate exhaust camshaft at hexagon against direction of rotation up to stop.

Note: The splines in the VANOS gear are now in contact; the exhaust camshaft cannot be rotated further.

Remove special tool 11 2 300. Rotate crankshaft in direction of rotation a further revolution up to overlap TDC position.





Cylinder bank 5 to 8:
Slacken six accessible bolts two turns.





Crank engine at central bolt in direction of rotation until 1st cylinder is at TDC firing position. Secure vibration damper with special tool 11 2 300.





Cylinder bank 5 to 8:
Slacken remaining six bolts two turns.





Cylinder bank 5 to 8:

Note: The camshafts have an opening. The 1st bearing caps have a locating bore.

Align camshaft opening to locating bore in bearing cap and secure in position with special tool 11 7 120.





Cylinder bank 5 to 8:
Release screws on VANOS adjustment unit.





Cylinder bank 5 to 8:
Carefully lever out VANOS adjustment unit at "intended" openings with a screwdriver on left and right.





Cylinder bank 5 to 8:
Pull off VANOS adjustment unit.





Remove special tool 11 2 300.





Caution: When removing the VANOS gear, ensure that no piston is in the TDC position.

With the VANOS adjustment unit removed, sprockets on intake and exhaust camshafts are not positively linked to the camshafts. Camshafts on cylinder bank 5 to 8 do not rotate.

Crank engine at central bolt against direction of rotation to 45, before TDC position.
Remove left timing case cover on cylinder bank 5 to 8, refer to Timing Components.
Remove piston for chain tensioner, refer to Timing Components.





Cylinder bank 5 to 8 (inlet side):
Remove slackened bolts. Take off spacer ring (1).





Cylinder bank 5 to 8 (inlet side):

Note: The spline hub (1) accommodates a plate spring and a supporting ring.

Take care: the supporting ring can easily fall out when removed.
Remove spline hub (1) with plate spring and supporting ring.





Cylinder bank 5 to 8 (inlet side):
Detach inlet sprocket wheel (3) from centering sleeve.
Keep inlet sprocket wheel (3) with chain tensioned.
Feed out inlet sprocket wheel (3).
Secure chain against slipping down.





Cylinder bank 5 to 8 (exhaust side):

Note: The spline hub (1) accommodates a plate spring and a supporting ring.

Take care: the supporting ring can easily fall out when removed.
Remove slackened bolts on exhaust side.
Remove spacer ring (2) and spline hub (1) with plate spring and supporting ring.





Cylinder bank 5 to 8 (exhaust side):
Take off spacer ring (2).





Cylinder bank 5 to 8:
Compress secondary chain tensioner at top and lock with special tool 11 7 140.





Cylinder bank 5 to 8:
Remove special tool 11 7 120.





Cylinder bank 5 to 8:

Note: Grip camshafts at hexagon head.

Release bolts on centering sleeves (1).





Cylinder bank 5 to 8:
Remove centering sleeves (1) on exhaust and inlet sides.





Cylinder bank 5 to 8:
Remove secondary chain drive with chain (1) and sprocket wheels (2).





Cylinder bank 5 to 8:
Withdraw toothed sleeves (2) from exhaust and inlet camshafts.





Connect special tool 12 6 050 in conjunction with special tool 12 6 411 to solenoid valves of VANOS adjustment unit. Connect special tool 12 6 411 to correct terminals on car battery.
Press button 1 on special tool 12 6 050 and simultaneously pull out toothed shaft of exhaust side by hand up to stop.
Press button 3 on special tool 12 6 050 and simultaneously pull out toothed shaft of inlet side by hand up to stop.





Caution: Left hand thread!

Brace against twin surface (1) and release hex head (2).
Release toothed shaft screw connection on inlet and exhaust sides.