Overhaul

Removing and installing actuator for camshaft (camshaft controller)

Preliminary work

1. Remove cylinder head cover (valve cover) on both cylinder banks.
2. The spark plugs should be removed to make the crankshaft easier to turn.

Removing actuator for camshaft (camshaft controller)

Notice
Incorrect handling of crankshafts
* Risk of damage to the timing system

-> Never turn the crankshaft against the rolling direction or when the chain tensioner is removed.
-> Proceed carefully with your work.
-> Only turn the engine at the crankshaft.
-> Reset the timing after working on the camshaft.
-> Observe general warning notes and working regulations.

Notice
Small parts falling into the timing case
* Risk of engine damage

-> Do not let the diamond washer and other small parts fall into the timing case.





Camshaft adjustment overview

1 - Screw, M12 Tighten fully after setting timing. Always use a new screw.
2 - Camshaft controller with integrated hexagon for countering
3 - Hydraulic valve for camshaft control
4 - Screw, M5 x 12





Staking bore 45 degrees before TDC of cylinder 1

1. Turn the crankshaft at the vibration balancer so that the vibration balancer's staking bore -2- is located approx. 45 degrees in front of the lower staking point on the timing-case cover -1-.
2. Remove chain tensioner.
3. Loosen all four screws on the camshafts (sprockets and camshaft controllers) by one to two turns. Counter at the respective hexagon.





Loosening camshafts (illustrated with timing-case cover removed)

Information
* Move the camshafts carefully. Do not force.
* Turn in the other direction if necessary.

Information
A data matrix coding is shown on the staking dihedron of the camshafts. This is a square black/white dotted marking used for electronic identification purposes during the production process. This marking can be used as an aid when inserting the camshafts into the cylinder head. All four camshafts press against the valves the least when the data matrix coding is facing upwards during installation.

4. Turn all four camshafts so that all the data matrix codings at the adjustment edges are pointing upwards almost simultaneously (this enables the camshafts to exert the minimum amount of pressure on the valve lifters). The camshafts are turned at their hexagon using an appropriate open-ended wrench. Observe identical information on assembling the camshafts.





Camshaft position for cylinders 1 to 4





Camshaft position for cylinders 5 to 8





Hexagon at camshaft

5. Loosen timing chain.
6. Remove screw for the respective camshaft controller -1- (counter at the hexagon) and carefully take out the camshaft controller with both hands under the timing chain. Carefully loosen the camshaft controller from behind using a rubber hammer if necessary.





Camshaft adjustment

1 - Screw, M12 Tighten fully after setting timing. Always use a new screw.
2 - Camshaft adjuster with integrated hexagon for countering
3 - Hydraulic valve for camshaft control
4 - Screw, M5 x 12





Loosening camshaft controller





Removing camshaft controller from chain

Installing actuator for camshaft (camshaft controller)

Information
The tightening specifications for the basic engine are stored centrally. Tightening torques and assembly instructions for other affected assemblies (e.g. chassis, electrics, transmission or body) or for peripheral engine equipment can be found in the corresponding documents.

1. Lift timing chain and place camshaft controller carefully on the camshaft. In order to have sufficient play in the timing chain, turn camshaft timing gear back and forth as required. Place timing chain on the camshaft controller.





Camshaft controller on camshaft





Turning camshaft timing gear

2. Position fastening screw and hexagon on the camshaft controller and screw in loosely (it must still be possible to turn the camshaft controller).





Camshaft adjustment

1 - Screw, M12 Tighten fully after setting timing. Always use a new screw.
2 - Camshaft adjuster with integrated hexagon for countering
3 - Hydraulic valve for camshaft control
4 - Screw, M5 x 12

3. Screw in the four screws of the sprockets and camshaft controller as far as possible (it must still be possible to turn the sprockets and camshaft controller to adjust the timing).
4. Set the timing. Do not tighten the sprockets and camshaft controller to the final tightening torque until the timing has been set.

Subsequent work

1. Fit cylinder head cover (valve cover).
2. Fit spark plugs.