Replacing the timing belt
Special tools: 951 2797 , 999 5006 , 951 2050 , 999 5460 , 999 5506
Conditions
Note! The engine must be cold (Ä…20°C) when replacing the timing belt.
Note! Used belts must not be reinstalled.
-Make a note of the radio code
-Turn the ignition key to position 0. Disconnect the battery ground lead according to Note when
disconnecting and connecting the battery lead
-Remove the engine cover
-Remove the drive belt for auxiliary equipment according to Replacing the drive belt for auxiliary
equipment .
Removing the engine mounting, timing belt side
-Remove the engine mounting on the timing belt side according to Replacing the engine mounting on
the timing belt side .
Removing the timing belt cover
-Remove the studs at the engine mounting
-Remove the 4 mounting screws for the timing belt cover
-Remove the timing belt cover.
Turn the crankshaft to top dead centre (TDC)
-Turn the steering wheel fully to the right. Remove the cover at the crankshaft pulley
-Remove the valve cover
-Turn the crankshaft to top dead centre (TDC) for cylinder 1 (flywheel side). Both the cams on the
camshaft for cylinder 1 must be angled upwards.
Note! Mark the position of the indicator on the camshaft pulley.
-Remove the plug to the right of the dip stick (Tx E14). Insert an 8 mm locking pin through the opening
-Check that the locking pin locks the crankshaft.
Removing the timing belt
-Remove the crankshaft pulley (1)
-Slacken off the belt tensioner (2)
-Remove the timing belt (3)
-Clean and check the pulleys and the tensioner.
Note! Used belts must not be reinstalled.
Replacing the timing belt tensioner
-Remove the 2 screws for the mounting plate
-Remove the timing belt tensioner
-Insert the new timing belt tensioner
-Tighten the two mounting screws. Tighten to 10 Nm.
Installing the new timing belt
Note! Check that the belt is the correct type.
Check that the locking pin is still locking the crankshaft.
Install the new timing belt.
The mark on the timing belt must correspond with the markings on the crankshaft and the camshaft.
Note! Note the following when installing the belt:
-The direction of rotation of the belt (indicated by arrows on the belt)
-The order in which the belt must be installed over the pulleys (see the numbering on the diagram)
-The belt tensioner must be quite loose to prevent damage to the belt.
Hint: Before installing the belt on the pulley for the high pressure pump, turn the camshaft slightly in its
direction of rotation so that the belt tensions against the tensioner pulley. When the belt is positioned, turn
the camshaft back so that the belt is tensioned slightly at the water pump.
Installing the crankshaft pulley
-Install the crankshaft pulley.
Note! Always use a new screw.
-Check that the locking pin is still locking the crankshaft
-Tighten the crankshaft pulley:
-Step 1: Tighten to: 20 Nm
-Step 2: Angle-tighten: 115° Ä… 15°. Use tool 951 2050 .
Adjusting the tension of the timing belt
Caution! Read the supplied instructions for special tool 951 2797 .
Ensure that no other sources of sound can affect the measurement (engine noise etc.)
Step 1
-Remove the lock pin from the crankshaft.
-Install an M6 screw so that the position (1) of the belt tensioner can be adjusted
-Tighten the timing belt to obtain an initial frequency of 88 Hz Ä… 3 Hz.
-Tighten the belt tensioner by hand.
Step 2
-Turn the crankshaft 4 turns in the direction of normal engine rotation.
Note! This ensures that the timing belt has rotated at least one complete revolution.
-Turn the crankshaft to top dead centre (TDC) for cylinder 1. Press the lock pin into the crankshaft.
Check that the locking pin locks the crankshaft.
Check the markings on the camshaft and fuel injection pump. Check the position of the crankshaft
-Remove the lock pin from the crankshaft.
-Check the tension of the timing belt. Adjust if necessary. 85 Hz Ä… 3 Hz
-Tighten the locking screw for the belt tensioner. Tighten to 50 Nm.
Caution! Do not turn the crankshaft again to check the tension.
-Remove the M6 adjustment screw
-Install the plug in the cylinder block. Use locking fluid P./N 1161053. Tighten to 20 Nm.
Installing the timing belt cover
-Install the timing belt cover. Tighten to 7 Nm
-Install the threaded end (A)
-Install the studs in the holes closest to the engine.
Installing the engine mounting on the timing belt side
Install the engine mounting on the timing belt side according to Replacing the engine mounting on the
timing belt side .
Finishing
-Install the drive belt for auxiliary equipment, see Replacing the drive belt for auxiliary equipment
-Install the engine cover
-Turn the ignition key to position II. Connect the negative battery lead according to Note when
disconnecting and connecting the battery lead
-Enter the radio code
-Start the engine and check the function.
Checking diagnostic trouble codes (DTCs)
Check and erase any diagnostic trouble codes (DTCs).