Audi Workshop Service and Repair Manuals

Removing and installing toothed belt Special tools and workshop equipment required

t  2-hole pin wrench -T10020-

Removing –  Lift off engine cover -arrows-.

–  If fitted, detach cover -1- on right of engine compartment.

–  Disengage solenoid valve 1 for activated charcoal filter system -N80--item 1- at air duct. –  Unscrew bolts -arrows-. –  Remove air duct -2-.   Note

Before removing, mark direction of rotation of poly V-belt with chalk or felt-tipped pen. If the belt runs in the opposite direction when it is refitted, this can cause breakage. –  Turn the tensioner in the direction of the -arrow- to slacken the poly V-belt. –  Remove poly V-belt.

–  Unscrew bolts -arrows- and remove poly V-belt tensioner.

–  Turn quick-release fastener -item 1- 90° clockwise. –  Raise retaining tabs -arrows- and detach upper toothed belt cover.   Caution The engine must only be turned at the crankshaft, in the direction of normal engine rotation (clockwise).

–  Turn crankshaft at central bolt of crankshaft toothed belt sprocket in direction of engine rotation to TDC mark for No. 1 cylinder -arrows-.

–  At the same time the marking on front of camshaft sprocket must align with the marking on the rear toothed belt cover -arrows-. If necessary, turn crankshaft one turn further.

–  Unbolt pulley.

–  Remove toothed belt cover (centre and bottom) -arrows-.

–  Mark the rotation direction of toothed belt with chalk or a felt-tipped pen. –  Loosen nut on tensioning roller -arrow- several turns. –  Remove toothed belt. Installing (adjusting valve timing)   Note t  Toothed belt adjustment is also to be performed as follows when carrying out repair work which only requires toothed belt to be removed from camshaft sprocket. t  The crankshaft must not be at TDC at any cylinder when the camshaft is turned. Otherwise, there is a risk of damage to valves and piston crowns. –  Fit toothed belt on crankshaft sprocket (note rotation direction). –  Install bottom toothed belt cover.   Note

The pulley can only be installed in one position: the hole -arrow- in the pulley must fit over the projection on the toothed belt sprocket on the crankshaft. –  Secure pulley. Note positive location -arrow-.

–  Align mark on camshaft sprocket with mark on toothed belt cover -arrows-.

–  Check again that crankshaft is at TDC of No. 1 cylinder -arrow-.

–  Fit toothed belt in the sequence: coolant pump, tensioning roller, camshaft sprocket. –  Note correct position of semi-automatic tensioning roller: l  Retaining lug -arrow- must engage in slot on cylinder head.

–  Turn tensioning roller at eccentric adjuster to stop in -direction of arrow- using 2-hole pin wrench -T10020-. –  Slacken tensioning roller until pointer -2- is approx. 10 mm below the notch -1-. –  Again, turn tensioning roller at eccentric adjuster to stop in -direction of arrow-. –  Slacken tensioning roller again until pointer -2- is approx. 10 mm below the notch -1-. –  Then tension tensioning roller until pointer -2- and notch -1- are back in line.   Note Check the position of notch and pointer on tensioning roller using a mirror.

–  Tighten securing nut to 23 Nm -arrow-. –  Turn crankshaft at central bolt on toothed belt sprocket two revolutions in direction of engine rotation and check whether camshaft and crankshaft markings align at TDC with their respective reference points. –  Check again whether toothed belt is tensioned properly, repeat adjustment procedure if necessary. –  Install centre section of toothed belt cover. –  Install top section of toothed belt cover (make sure it engages securely on centre section of toothed belt cover).

–  Install poly V-belt tensioner -arrows-. –  Install poly V-belt → Chapter. Tightening torques

Component	Nm
Tensioning roller to cylinder head	23
Toothed belt cover (bottom and centre section) to cylinder block	10 → Note
Pulley to toothed belt sprocket	10 + 90° → Note → Note
Tensioner for poly V-belt to bracket for ancillaries	23

1)  Install using locking fluid → Parts catalogue 2)  Renew bolts. 3)  90° equals a 1/4 turn.