Removal
Removal of cylinder heads is described separately from installation.
Cylinder bank 1 to 4:
Remove bracket (1) for cable channel.
Cylinder bank 1 to 4:
Note: Cylinder head bolts on cylinders 4 and 8 are only accessible after signal rings have been removed.
Caution: Risk of damage to pulse generators (2).
Remove pulse generators (2) of exhaust and inlet camshafts or release screws (1) with long socket.
Note: For purposes of picture clarity, the lug for raising the engine is not shown.
Cylinder bank 1 to 4:
Grip camshaft at hexagon head and release banjo bolt (1).
Remove signal rings.
Cylinder bank 5 to 8:
Caution: Risk of damage to pulse generators (2).
Remove pulse generators (2) of exhaust and inlet camshafts or release screws (1) with long socket.
Cylinder bank 5 to 8:
Grip camshaft at hexagon head and release banjo bolt (1).
Remove signal rings.
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 both cylinder banks 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 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 director 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 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:
Unclip plug connection for solenoid valves on cylinder bank 5 to 8 from bracket.
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.
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 director 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 1 to 4:
Slacken six accessible bolts two turns.
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 1 to 4:
Slacken remaining six bolts two turns.
Cylinder bank 5 to 8:
Slacken remaining six bolts two turns.
Cylinder bank 1 to 4:
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:
Align camshaft opening to locating bore in bearing cap and secure in position with special tool 11 7 120.
Cylinder bank 1 to 4:
Release screws on VANOS adjustment unit.
Cylinder bank 1 to 4:
Carefully lever out VANOS adjustment unit at "intended" openings with a screwdriver on left and right.
Cylinder bank 1 to 4:
Pull off VANOS adjustment unit.
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: No piston must be in the TDC position when the cylinder heads are removed.
With the VANOS adjustment unit removed, sprockets on intake and exhaust camshafts are not positively linked to the camshafts. Camshafts do not rotate.
Crank engine at central bolt against direction of rotation to 45, before TDC position.
Remove chain tensioning piston.
Remove right timing case cover on cylinder bank 1 to 4.
Remove left timing case cover on cylinder bank 5 to 8.
Cylinder bank 1 to 4 (inlet side):
Remove slackened bolts. Take off spacer ring (1).
Cylinder bank 1 to 4 (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 1 to 4 (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 (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:
Detach sliding rail from cylinder head.
Note: Use special tool 11 2 250 to release cylinder head bolts.
Use a socket with 3/8" drive and a short extension at narrow points.
Release cylinder head bolts on both cylinder heads in sequence 10 to 1.
Lift off cylinder heads.