Note: This describes the operating procedure for a gasoline engine only.
4-cylinder engine
Weakening
Remove the upper timing belt cover.
Place the HAZET 2587 tool or a suitable spanner on the tension roller.
Loosen the tension roller fastening nut with an open-end wrench.
Turn the roller to the left and loosen the toothed belt.
Caution: If the timing belt has been removed or moved, the valve timing must be reset.
Tension
Turn the tension roller to the right in the direction of the arrow and tighten the toothed belt.
The tension should be such that the toothed belt in the middle between the camshaft and intermediate shaft gears can be turned 90° with the index finger and thumb.
Tighten the lock nut on the tension roller to 45 Nm.
Engine 115 hp, letter designation AAD
This engine is equipped with a thermal tensioner pulley. This pulley automatically compensates for the temperature-induced change in the length of the timing belt, but the timing belt should be tightened as part of maintenance.
Weakening
Loosen the toothed belt on a 4-cylinder engine without a thermal roller. To do this, loosen bolt -1 -
Tension
The engine must be at room temperature.
Turn the nut holder in the direction of the arrow and tighten the timing belt.
When tensioned correctly, the timing belt in the middle between the camshaft and intermediate shaft gears can be turned 90° with the index finger and thumb.
Tighten bolt -1 - with a force of 20 Nm
Install the upper timing belt cover
Start the engine. If the timing belt whistles, it is too tight.
5-cylinder engine
Weakening
Remove the timing belt cover.
Loosen the 3 bolts securing the water pump of the cooling system, turn the pump to the right and loosen the toothed belt.
Tension
Turn the water pump to the left (up) using a crowbar and tighten the timing belt.
When tensioned correctly, the timing belt midway between the camshaft gear and the water pump can be turned 90° (¼ turn) with your index finger and thumb.
Tighten the water pump mounting bolts
Check the timing belt tension again
Install the timing belt cover.
Start the engine. A whistling toothed belt indicates that it is over-tensioned.
Content source: the specified website: AUDImanual