Dismantling the Belt Drive

Dismantling the belt drive

Special tools:
999 5304 SEPARATOR 999 5304 Separator
999 5433 COUNTERHOLD 999 5433 Counterhold

Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information in the illustrations is always correct.

Aligning the engine according to the marking





Install the upper timing belt cover.
Turn crankshaft clockwise until the markings on the crankshaft belt pulley and the timing belt pulley are aligned with the markings on the oil pump and the upper timing belt cover
Remove the upper timing belt cover.

Removing the vibration damper





Remove the 4 screws. Use the crankshaft center nut as a counterhold.
Install counterhold 999 5433 COUNTERHOLD 999 5433 Counterhold and remove the center nut.
Remove counterhold 999 5433.
Work the vibration damper loose.

Removing the timing belt





Engines without variable valve timing

Slacken off the belt tensioner center screw slightly.
Turn the eccentric on the belt tensioner clockwise with a 6 mm (0.2 in) Allen key to "10 o'clock".
Remove the timing belt.

Engines with variable valve timing

Turn the variable valve timing unit clockwise so that the timing belt is unloaded. Use a Tx55 torx wrench and install the variable valve timing unit center plug.
Remove the timing belt from the camshaft pulleys.
Carefully allow the variable valve timing to rotate back in to place.
Remove the timing belt.

Removing the crankshaft pulley





Use puller 999 5304 SEPARATOR 999 5304 Separator and two M8 x 45 mm (1.8 in) screws with washers.
Pull off the timing gear pulley.

Removing the belt tensioner and idler pulley





Remove the belt tensioner and idler pulley.
Check the rolling surface and the bearings.
Check for any noise. Check for any play in the bearings.
Check that the rolling surfaces are smooth and clean.

Removing oil pump




Remove the belt protection from the oil pump.
Remove the four oil pump screws.
Carefully work the oil pump out. Use a groove-cut chisel with stop lugs.
Carefully draw the oil pump past the end of the oil pump.
Carefully clean the gasket face and mating surfaces.

Checking the oil pump




Disassemble the oil pump.
Clean and check all components.
Check for damage and wear.
In particular check the half-moon shaped insert (the surface between the suction and pressure sides).
Replace the oil pump in the event of a fault.
Assemble the oil pump.

Removing the coolant pump / timing belt cover




Remove the screws.
Carefully tap the pump pulley with a rubber mallet.
Work the pump loose.
Carefully clean the gasket face and mating surfaces.
Remove the inner timing belt cover.

Removing the thermostat / thermostat housing




Remove the cover over the thermostat (Tx40).
Lift out the thermostat
Remove the hose for the water heated crankcase ventilation.
Remove the thermostat housing from the cylinder head.
Carefully clean the gasket face and mating surfaces.
Remove the fuel pressure line.

Checking the opening function of the thermostat




The thermostat can be tested in warm water.
Maximum opening must happen within 2 minutes in water at opening temperature.
Marking 90°C
Begins to open at 90°C
Fully open at 105°C