Left Camshaft Adjustment Unit

Left Camshaft Adjustment Unit

Remove intake filter housing with air-mass flow sensor. Service and Repair
Remove fan impeller with fan clutch and fan cowl.Service and Repair
Remove both cylinder head covers. Service and Repair
Remove spark plugs. Service and Repair

Note: In TDC firing position, the inlet camshaft 1 to 4 twists in the splines of the camshaft adjustment unit.

Caution: This twisting is caused by the position of the cams and is not an indication for incorrect timing.

Removal: Removal of the left camshaft adjustment unit is described separately from installation.

Note: Assembly sequence for removal and installation is different.

Remove oil lines on left and right of cylinder head.

Turn engine in direction of rotation as far as TDC firing position of first cylinder.

Secure crankshaft with special tool 11 2 300 in TDC firing position of first cylinder.
Note: X5 (E53) uses special tool # 11 5 180.

Caution: Remove special tool 11 2 300 before starting engine.

Remove piston for chain tensioner. Service and Repair
Remove both top timing case covers. Timing Case Cover Upper

Caution: Left-hand threads.

Release nut (1) on sensor gear screw connection on cylinder bank 5 to 8.

Remove sensor gear (2) on cylinder bank 5 to 8.

Caution: Left-hand threads.

Release nut (1) on sensor gear screw connection on cylinder bank 1 to 4.

Remove sensor gear (2) on cylinder bank 1 to 4.

Caution: Do not damage the cylinder head.

If necessary, machine open-end wrench accordingly.
When unfastening screw connection on camshaft, brace camshaft or hex head.

Caution: Left-hand threads.

Slacken screw connection (1) of exhaust camshaft on cylinder bank 5 to 8 by approx. half a turn.

Caution: Left-hand threads.

When unfastening screw connection on camshaft, brace camshaft or hex head.
Slacken screw connection (1) of exhaust camshaft on cylinder bank 1 to 4 by approx. half a turn.

Caution: Left-hand threads.

When unfastening screw connection on camshaft, brace camshaft or hex head.
Slacken screw connection (2) of inlet camshaft on cylinder bank 5 to 8 by approx. half a turn.

Caution: Left-hand threads.

When unfastening screw connection on camshaft, brace camshaft or hex head.
Slacken screw connection (2) of inlet camshaft on cylinder bank 1 to 4 by approx. half a turn.

Align camshafts.
Fit special tool 11 2 445 / 441 to camshafts on cylinder bank 1 to 4.

Fit special tool 11 2 443 to special tool 11 2 445 / 441 and secure with special tool 11 2 444 using the spark plug thread.

Align camshafts.
Fit special tool 11 2 446 / 442 to camshafts on cylinder bank 5 to 8.

Fit special tool 11 2 443 to special tool 11 2 446 / 442 and secure with special tool 11 2 444 using the spark plug thread.

Compress chain tensioner on cylinder bank 5 to 8 and lock with special too 1 11 3 310.

Caution: Left-hand threads.

Remove screws (1 and 2) on cylinder bank 5 to 8.

Pull exhaust sprocket wheel (1) and camshaft adjustment unit (2) forwards until they are no longer located in position on the camshafts.

Feed out timing chain (1) forwards over sprocket wheel of camshaft adjustment unit (2).
Feed out exhaust sprocket wheel with secondary chain and camshaft adjustment unit (2).

Installation:
Installation of the left camshaft adjustment unit is described separately from removal. Assembly sequence for removal and installation is different.

Pull timing chain up, fit camshaft adjustment unit (2) with exhaust sprocket wheel and positioned secondary chain and feed on timing chain (1) from front over sprocket wheel of camshaft adjustment unit (2).

Note: The position of the elongated holes on the exhaust sprocket wheel is not assigned and can be freely selected.

The position of the camshaft adjustment unit (2) when feeding on the timing chain (1) is not assigned and can be freely selected.

Position exhaust sprocket wheel (1) and camshaft adjustment unit (2) on camshafts.

Caution: Left-hand threads.

Insert screws (1 and 2) on cylinder bank 5 to 8 and initially tighten without play, but do not tighten down yet.

Compress chain tensioner and remove special tool 11 3 310.

Fit special tool 11 7 380 to right cylinder head on cylinder bank 1 to 4.

Install special tool 11 3 390 in special tool 11 7 380.
Screw in adjustment screw on tensioning rail but do not tighten yet.

Connect a commercially available multimeter to a contact pin on camshaft adjustment unit and to screw connection on oil line on cylinder bank 5 to 8.
Set multimeter to acoustic continuity test.

Attach special tool 11 6 440 to camshaft adjustment unit on cylinder bank 5 to 8 and move at 40 Nm to left-hand stop.
Check left-hand stop of camshaft adjustment unit with acoustic continuity test on multimeter.

Note: Turning the camshaft adjustment unit at 40 Nm to the left-hand stop ensures that the end position has been reached and there is no longer an "oil cushion" before the left-hand stop of the camshaft adjustment unit.

In the camshaft adjustment unit, there are three contacts which are closed when the unit is at the left-hand stop.
During the acoustic continuity test with the multimeter, a sound signal can be heard when the camshaft adjustment unit is at the left-hand stop.

Caution: Left-hand threads.

Tighten screw connection (2) of inlet camshaft on cylinder bank 5 to 8 to an initial torque of 15 Nm and then slacken off by a 1/4 turn.

Caution: Left-hand threads.

Tighten screw connection (1) of exhaust camshaft on cylinder bank 5 to 8 to an initial torque of 15 Nm and then slacken off by a 1/4 turn.

Connect a commercially available multimeter to a contact pin on camshaft adjustment unit and to screw connection on oil line on cylinder bank 1 to 4.
Set multimeter to acoustic continuity test.

Attach special tool 11 6 440 to camshaft adjustment unit on cylinder bank 1 to 4 and move at 40 Nm to left-hand stop.
Check left-hand stop of camshaft adjustment unit with acoustic continuity test on multimeter.

Caution: Left-hand threads.

Tighten screw connection (2) of inlet camshaft on cylinder bank 1 to 4 to an initial torque of 15 Nm and then slacken off by a 1/4 turn.

Caution: Left-hand threads.

Tighten screw connection (1) of exhaust camshaft on cylinder bank 1 to 4 to an initial torque of 15 Nm and then slacken off by a 1/4 turn.

Tighten bow cover by turning the adjusting screw on the special tool 11 3 390 with special tool 00 9 250 to 0.7 Nm.

Note: If installation tolerance is unfavorable, attach special tool 00 9 250 from underside.

Note: When the timing chain is pretensioned, the camshaft adjustment unit moves and must be reset to the left-hand stop.

Attach special tool 11 6 440 to camshaft adjustment unit on cylinder bank 5 to 8 and move at 40 Nm to left-hand stop.
Check left-hand stop of camshaft adjustment unit with acoustic continuity test on multimeter.

Caution: Do not damage the cylinder head.

If necessary, machine open-end wrench accordingly.
When tightening down camshaft screw connection, grip camshaft at hexagon head.

Caution: Left-hand threads.

Tighten down screw connection (2) of inlet camshaft on cylinder bank 5 to 8.
Tightening Torque, refer to Engine, Specifications.

Caution: Left-hand threads.

When tightening down camshaft screw connection, grip camshaft at hexagon head.
Tighten down screw connection (1) of exhaust camshaft on cylinder bank 5 to 8.
Tightening Torque, refer to Engine, Specifications.

Caution: Left-hand threads.

When tightening down camshaft screw connection, grip camshaft at hexagon head.
Tighten down screw connection (2) of inlet camshaft on cylinder bank 1 to 4.
Tightening Torque, refer to Engine, Specifications.

Caution: Left-hand threads.

When tightening down camshaft screw connection, grip camshaft at hexagon head.
Tighten down screw connection (1) of exhaust camshaft on cylinder bank 1 to 4.
Tightening Torque, refer to Engine, Specifications.

Attach sensor gear (2) to cylinder bank 1 to 4.

Caution: Left-hand threads.

Fit nut (1) of sensor gear screw connection on cylinder bank 1 to 4 and initially tighten without play, but do not tighten down yet.

Note:
Special tool kit 11 6 450 comprises:
Special tool 11 6 451 for cylinder bank 1 to 4
Special tool 11 6 452 for cylinder bank 5 to 8
Align locating bore (1) on sensor gear of cylinder bank 1 to 4 to positioning pin on special tool 11 6 451. Fit special tool 11 6 451, insert screws and initially tighten without play. Press special tool 11 6 451 downwards and align to cylinder head. Tighten down special tool 11 6 451.

Caution: Left-hand threads.

Tighten down nut (1) on sensor gear screw connection.
Tightening Torque, refer to Engine, Specifications.

Remove special tool 11 6 451 from right cylinder head on cylinder bank 1 to 4.

Attach sensor gear (2) to cylinder bank 5 to 8.

Caution: Left-hand threads.

Fit nut (1) of sensor gear screw connection on cylinder bank 5 to 8 and initially tighten without play, but do not tighten down yet.

Note:
Special tool kit 11 6 450 comprises:
Special tool 11 6 451 for cylinder bank 1 to 4
Special tool 11 6 452 for cylinder bank 5 to 8

Align locating bore (1) on sensor gear of cylinder bank 5 to 8 to positioning pin on special tool 11 6 452. Fit special tool 11 6 452, insert screws and initially tighten without play. Press special tool 11 6 452 downwards and align to cylinder head. Tighten down special tool 11 6 452.

Caution: Left-hand threads.

Tighten down nut (1) on sensor gear screw connection.
Tightening Torque, refer to Engine, Specifications.

Remove special tool 11 6 452 from left cylinder head on cylinder bank 5 to 8.

Remove special tools 11 2 444 / 443 / 445 / 441.

Remove special tools 11 2 444 / 443 / 442 / 446.

Relieve tension on special tool 11 3 390.
Remove special tool 11 7 380 from right cylinder head on cylinder bank 1 to 4.

Install oil lines on left and right of cylinder head.

Install both top timing case covers. Timing Case Cover Upper
Install chain tensioning piston. Service and Repair

Remove special tool 11 2 300.
Note: X5 (E53) uses special tool # 11 5 180.
(Remove them before starting engine).

Assemble engine.