Special tools required:
(cylinder bank 1 to 4)
Necessary preliminary tasks:
Removal:
Removal of inlet and exhaust adjustment units is described separately from installation.
IMPORTANT: Screw (1) is a special screw and must not be replaced with a normal M8 screw.
Release screw (1).
Unclip oil line (3) from retainers (2) and remove.
Fig. 571: Identifying Retainer And Screw
Crank engine at central bolt in direction of rotation to firing TDC position of 1st cylinder.
NOTE: In firing TDC position, cam of exhaust camshaft at 1st cylinder points upwards at an angle.
Cam of inlet camshaft points downwards at an angle.
Fig. 572: Locating Cam Lobe Position
NOTE: Alignment hole for TDC position is at front on timing case cover.
Crank engine at central bolt and secure vibration damper with special tool 11 9 190 in firing TDC position of 1st cylinder.
Fig. 573: Identifying Special Tool (11 9 190)
IMPORTANT: When the engine is shut down, the inlet and exhaust adjustment unit is normally locked in its initial position.
The situation may arise in some individual cases where this initial position is not reached and the camshaft can continue to be rotated in the adjustment range of the adjustment unit.
In order to avoid incorrect timing adjustment, it is essential to check the locking of the adjustment unit and if necessary perform locking by rotating the camshafts.
Checking locking of inlet adjustment unit in initial position: Engage hexagon head of inlet camshaft and attempt to rotate inlet camshaft carefully against direction of rotation.
If there is no fixed connection between inlet camshaft and inlet adjustment unit, rotate inlet camshaft against direction of rotation as far as it will go.
The inlet adjustment unit is locked in the initial position when the inlet camshaft is non-positively connected to the inlet adjustment unit.
Fig. 574: Rotating Inlet Camshaft
Checking locking of exhaust adjustment unit in initial position: Engage hexagon head of exhaust camshaft and attempt to rotate exhaust camshaft carefully in direction of rotation.
If there is no fixed connection between exhaust camshaft and exhaust adjustment unit, rotate exhaust camshaft in direction of rotation as far as it will go.
The exhaust adjustment unit is locked in the initial position when the exhaust camshaft is non-positively connected to the exhaust adjustment unit.
Fig. 575: Rotating Exhaust Camshaft
IMPORTANT: If the inlet or exhaust adjustment unit of the camshafts "cannot" be locked as described, the adjustment unit is faulty and must be replaced.
Remove special tool 11 9 190.
Crank engine at central bolt against direction of rotation to 45º before TDC position.
Fig. 576: Identifying Crank Shaft Rotation Angle
NOTE: When slackening screws, grip camshafts at hexagon head.
Slacken screws of exhaust and inlet adjustment unit.
Fig. 577: Locating Slacken Screws Of Exhaust And Inlet Adjustment Unit
Remove screw on inlet adjustment unit.
Fig. 578: Identifying Inlet Adjustment Unit Screw
Vigorously press back tensioner rail (3) several times to remove oil in chain tensioner.
Feed out inlet adjustment unit (1).
Fig. 579: Pressing Back Tensioner Rail
Remove screw on exhaust adjustment unit.
Fig. 580: Identifying Exhaust Adjustment Unit Screw
Feed out exhaust adjustment unit (2).
Secure timing chain to prevent it from sliding down.
Fig. 581: Identifying Exhaust Adjustment Unit
Installation:
Installation of inlet and exhaust adjustment units is described separately from removal.
IMPORTANT: Danger of mix-up:
Inlet and exhaust adjustment units are different.
Mixing up the inlet and exhaust adjustment units will cause damage to the engine.
Fig. 582: Identifying Inlet And Exhaust Adjustment Unit Marked With EIN And
IN
NOTE: The exhaust adjustment unit on cylinder bank 1 to 4 also has a metal clip (3) for driving the vacuum pump.
Fig. 583: Identifying Metal Clip
NOTE: Position of exhaust adjustment unit (2) to timing chain can be freely selected.
Pull timing chain up.
Feed exhaust adjustment unit (2) into timing chain and fit onto exhaust camshaft.
Fig. 584: Identifying Exhaust Adjustment Unit
Replace screw.
Install screw on exhaust adjustment unit.
Tighten screw without play and then slacken off again by half a turn.
Fig. 585: Identifying Exhaust Adjustment Unit Screw
NOTE: Position of inlet adjustment unit (1) to timing chain can be freely selected.
Pull timing chain up.
Feed inlet adjustment unit (1) into timing chain.
Press tensioner rail (3) back and fit inlet adjustment unit (1) onto inlet camshaft.
NOTE: If tensioner rail (3) cannot be pressed back far enough to enable fitting of inlet adjustment unit (1):
Slacken off chain tensioner by approx. three turns.
Fit inlet adjustment unit (1).
Replace and insert screw on inlet adjustment unit (1).
Tighten down chain tensioner.
Tightening torque of chain tensioner, 11 31 8AZ.
Fig. 586: Pressing Back Tensioner Rail
Tighten screw on inlet adjustment unit without play and then slacken off again by a half turn.
Fig. 587: Identifying Inlet Adjustment Unit Screw
Get special tool kit 11 9 460 ready for securing camshafts.
NOTE: Special tool 11 9 461 for securing inlet camshaft.
Special tool 11 9 462 for securing exhaust camshaft.
Special tool 11 9 463 (holder with screw).
Fig. 588: Identifying Special Tool (11 9 461), (11 9 462) And (11 9 463)
Place special tool 11 9 461 on inlet camshaft and align inlet camshaft so that special tool 11 9 461 rests without a gap on cylinder head.
Fig. 589: Identifying Special Tool (11 9 461)
Fit special tool 11 9 463, secure screw (1) in thread for oil line and tighten down by hand.
Fig. 590: Identifying Special Tool (11 9 461) And (11 9 463)
IMPORTANT: Make sure screws of inlet and exhaust adjustment units have been slackened off.
Crank engine at central bolt from 45º before TDC position in direction of rotation to firing TDC position.
Secure vibration damper with special tool 11 9 190 in firing TDC position of 1st cylinder.
Fig. 591: Identifying Special Tool (11 9 190)
NOTE: When tightening down screw (1), grip camshaft at hexagon head.
Tighten down screw (1) of inlet adjustment unit.
Tightening torque 11 36 16AZ.
Fig. 592: Identifying Special Tool (11 9 461)
Release screw (1) and remove special tools 11 9 463 /11 9 461 from inlet camshaft.
Fig. 593: Identifying Special Tool (11 9 461) And (11 9 463)
Place special tool 11 9 462 on exhaust camshaft and align exhaust camshaft so that special tool 11 9 462 rests without a gap on cylinder head.
Fig. 594: Identifying Special Tool (11 9 462)
Fit special tool 11 9 463 , secure screw (1) in thread for oil line and tighten down by hand.
Fig. 595: Identifying Special Tool (11 9 462) And (11 9 463)
NOTE: When tightening down screw (2), grip camshaft at hexagon head.
Tighten down screw (2) of exhaust adjustment unit.
Tightening torque 11 36 16AZ.
Fig. 596: Identifying Special Tool (11 9 462)
Release screw (1) and remove special tools 11 9 463 /11 9 462 from exhaust camshaft.
Fig. 597: Identifying Special Tool (11 9 462) And (11 9 463)
Remove special tool 11 9 190.
Crank engine at central bolt twice in direction of rotation until engine returns to firing TDC position of 1st cylinder.
Secure vibration damper with special tool 11 9 190 in firing TDC position of 1st cylinder.
Fig. 598: Identifying Special Tool (11 9 190)
Place special tool 11 9 461 on inlet camshaft and check timing.
NOTE: The timing is correctly adjusted when special tool 11 9 461 rests flat on the cylinder head or protrudes by up to 0.5 mm to the exhaust side.
Fig. 599: Identifying Special Tool (11 9 461)
Place special tool 11 9 462 on exhaust camshaft and check timing.
NOTE: The timing is correctly adjusted when special tool 11 9 462 rests flat on the cylinder head or protrudes by up to 0.5 mm to the exhaust side.
Fig. 600: Identifying Special Tool (11 9 462)
Remove all special tools.
IMPORTANT: Screw (1) is a special screw and must not be replaced with a normal M8 screw.
Clip oil line (3) into retainers (2).
Insert screw (1) and tighten down.
Assemble engine.
Fig. 601: Identifying Retainer And Screw