Installation

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

Cylinder bank 5 to 8:
Check setting of exhaust and inlet camshafts:
If necessary, rotate exhaust camshaft at hexagon head until exhaust cam on cylinder 5 faces upwards.
If necessary, rotate inlet camshaft at hexagon head until inlet cam or cylinder 7 faces upwards.

Note: Coat all sliding surfaces on VANOS gear with engine oil as lubricant.

Cylinder bank 5 to 8:Install toothed sleeves (2) in exhaust and inlet camshafts.
Align openings in toothed sleeves (2) to tapped holes in camshafts.

Cylinder bank 5 to 8:

Note: The position of the tapped hole on the sprocket wheels is important for bolt accessibility. It does not affect function.

Place chain (1) on sprocket wheels (2) so that tapped holes on sprocket wheels are vertical.

Cylinder bank 5 to 8:
Place chain (1) and sprocket wheels (2) on camshafts.
Align chain (1) and sprocket wheels (2) so that stud (3) on bearing cap is flush with a tapped hole (3) on sprocket wheel.

Cylinder bank 5 to 8:
Push on centering sleeves (1) for exhaust and inlet sides, align bore,, to tapped holes in camshafts.

Cylinder bank 5 to 8:
Insert bolts for centering sleeves (1).

Note: Grip camshafts at hexagon head.
Tighten down bolts on centering sleeves (1).

Cylinder bank 5 to 8:

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

Align camshafts so that camshaft openings line up with locating bore in bearing cap.
Secure camshafts with special tool 11 7 120.

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

Cylinder bank 5 to 8 (exhaust side):
Fit spacer ring (2).
Align bores in spacer ring (2) to threads in sprocket wheel.

Cylinder bank 5 to 8 (exhaust side):

Note: The small support diameter of the plate spring (2) points in the direction of the supporting ring (3). Supporting ring is supported with retaining lugs in spline hub (1).

Insert plate spring (2) and supporting ring (3) in spline hub (1).

Cylinder bank 5 to 8 (exhaust side):

Note: Fit spline hub (1) with plate spring and supporting ring so that bore (2) is positioned as in illustration.

Cylinder bank 5 to 8 (exhaust side):
Fit spacer ring (2).
Insert all bolts and initially tighten without play.
Then slacken bolts again until spline hub (1) can be moved with fingers.

Cylinder bank 5 to 8 (inlet side):
Keep timing chain tensioned and thread inlet sprocket wheel (3) on.

Note: The position of the bores in the inlet sprocket wheel (3) can be freely selected; they do not have to line up with the threads yet.

Attach inlet sprocket wheel (3) to centering sleeve. Do not insert "any" bolts in inlet sprocket wheel (3) yet.

Note: If a chain tensioning piston is re-used, drain the oil chamber in the chain tensioner.

Install chain tensioning piston.

"No" bolts are installed in inlet sprocket wheel yet. Inlet sprocket wheel must not be allowed to slip off centering sleeve.
Rotate crankshaft from 45, before TDC position in direction of rotation up to TDC firing position. Secure vibration damper with special tool 11 2 300.

Cylinder bank 5 to 8 (inlet side):
Check position of inlet sprocket wheel (3) to threads.
In event of large deviation (thread not visible):
Detach inlet sprocket wheel (3) from centering sleeve while keeping timing chain tensioned, realign sprocket wheel (3) and refit.
In event of small deviation:
Place special tool 11 7 150 on toothed sleeve on exhaust side. Align secondary chain drive to bores in inlet sprocket wheel (3).

Cylinder bank 5 to 8 (inlet side):

Note: The small support diameter of the plate spring (2) points in the direction of the supporting ring (3). Supporting ring is supported with retaining lugs in spline hub (1).

Insert plate spring (2) and supporting ring (3) in spline hub (1).

Cylinder bank 5 to 8 (inlet side):
Install spline hub (1) with plate spring and supporting ring.

Note: Align spline hub (1) so that oil pump drive is positioned as in illustration.

Cylinder bank 5 to 8 (inlet side):
Fit spacer ring (2).
Insert all bolts and initially tighten without play.
Then slacken bolts again until spline hub (1) can be moved with fingers.
Install left timing case cover.

Caution: Left hand thread!
Install toothed shafts of inlet and exhaust sides.
Brace against twin surface (1) and release hex head (2).
Tightening torque 10 Nm.

Oil is sprayed when splined shafts are pressed back. Cover bore (1) with a cloth.
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 2 on special tool 12 6 050 and simultaneously press back toothed shaft of exhaust side by hand up to stop.
Press button 4 on special tool 12 6 050 and simultaneously press back toothed shaft of inlet side by hand up to stop.

Replace O-rings (1 and 2) on VANOS adjustment unit.
Coat O-rings (1) with oil as anti-friction agent.

Caution: O-rings (2) fall out very easily, secure with grease if necessary.

Cylinder bank 5 to 8:
Rotate spline hubs (1) of inlet and exhaust camshafts to right stop.

Cylinder bank 5 to 8:
Attach VANOS adjustment unit.

Cylinder bank 5 to 8:

Caution: Ensure that both VANOS splined shafts remain in initial position during assembly procedure.

Rotate splined shafts of inlet and exhaust sides until straight splines are engaged.
Push VANOS adjustment unit with splined shaft into VANOS gear until helical cut splines (2) are positioned shortly before meshing with spline hub (1).

Cylinder bank 5 to 8 (exhaust side):
If the helical cut splines cannot be pushed into the spline hub (1):
Place special tool 11 7 150 on bore in spline hub (1). Rotate spline hub (1) against direction of rotation until splined shaft (2) is positioned with spline hub (1) exactly "tooth-to-tooth gap".

Caution: The "first" fitting tooth must snap into place.

Cylinder bank 5 to 8 (inlet side):
Place special tool 11 7 150 on bore in spline hub (1). Rotate spline hub (1) against direction of rotation until splined shaft (2) is positioned with spline hub (1) exactly "tooth-to-tooth gap".

Caution: The "first" fitting tooth must snap into place.

Cylinder bank 5 to 8 (inlet side):
Align radial piston pump to driver on spline hub.

Note: Picture shows a schematic representation.

Push on VANOS adjustment unit only until O-rings of VANOS adjustment unit rest against timing case cover.

Caution: If this position is not reached, realign position of radial piston pump to driver.

Caution: Insert one bolt each on left and right and initially tighten without play. The bolts serve to locate the VANOS adjustment unit in position. Do "not" tighten down bolts yet. VANOS adjustment unit must "not" rest against timing case cover.

Cylinder bank 5 to 8:

Note: To tighten down screws on VANOS gear: use special tool 11 7 200.

Tighten down six accessible bolts (three on exhaust side and three on inlet side) on VANOS gear to 10 Nm.
Then slacken all six bolts again by a 1/4 turn.

Cylinder bank 5 to 8:
Install all bolts. Alternately tighten down bolts in 1/2 turn increments carefully and evenly until VANOS adjustment unit rests against timing( case cover.
Tighten down all bolts.

Remove special tool 11 2 300.

Caution: The camshafts remain locked in position with special tool 11 7 120.

Carefully rotate engine at central screw against direction of rotation until there is noticeable resistance and spline hubs are at the stop.

Note: This procedure creates compensation for play. Only with this compensation for play is the timing diagram correctly set.

Then crank engine again 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:
Remove special tool 11 7 120.
Remove special tool 11 2 300. Crank engine at central bolt in direction of rotation a further revolution up to overlap TDC position.

Cylinder bank 5 to 8:

Note: To tighten down screws on VANOS gear: use special tool 11 7 200.
Tighten down remaining six bolts on VANOS gear to 10 Nm.

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 1 to 4:
Remove oil line from VANOS adjustment unit.

Cylinder bank 1 to 4:
Fit special tool 11 7 130 to VANOS adjustment unit.
Connect compressed air (2 to 8 bar).

Cylinder bank 1 to 4:
Disconnect plug connection for solenoid valves on cylinder bank 1 to 4.
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 1 to 4. Connect special tool 12 6 411 to correct terminals on car battery.
Alternately press toggle switch buttons 1 and 2 several times on special tool 12 6 050.

Caution: Do not damage the cylinder head.

If necessary, machine open-end wrench accordingly.

Cylinder bank 1 to 4:
Press and hold down toggle switch button 1 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 1 to 4:
Alternately press toggle switch buttons 3 and 4 several times on special tool 12 6 050.

Cylinder bank 1 to 4:
Press and hold down toggle switch button 3 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.

Cylinder bank 1 to 4:
Check camshaft adjustment.

Note: Groove on 1st bearing cap is a little wider than groove in camshaft.

Groove on inlet and exhaust camshafts must be located inside groove on 1st bearing cap.

Cylinder bank 5 to 8:
Check camshaft adjustment.

Note: Groove on 1st bearing cap is a little wider than groove in camshaft.

Groove on inlet and exhaust camshafts must be located inside groove on 1st bearing cap.
If necessary, adjust camshaft timing, refer to Adjustments.

Cylinder bank 5 to 8:
Replace sealing rings.
Fit oil line to VANOS adjustment unit.
Tightening Torque, refer to Engine, Specifications.

Cylinder bank 1 to 4:
Remove special tool 11 7 130 from VANOS adjustment unit.
Replace sealing rings.
Attach oil line to VANOS adjustment unit.
Tightening Torque, refer to Engine, Specifications.
Assemble engine.

Caution: There is air in the VANOS system once it is opened.

In the first few seconds after start-up this results in a clearly discernible "rattling noise".
This rattling noise does "not" indicate incorrect assembly.
The rattling noise will disappear as soon as the oil pressure has built up and the system has vented.