Audi Workshop Service and Repair Manuals

Removing and installing toothed belt

Removing –  On vehicles with auxiliary/additional heater, remove bolts -arrows- securing exhaust pipe for auxiliary/additional heater to noise insulation.

–  Release quick-fasteners -1- and -2- and take off front noise insulation. –  Remove front bumper cover → General body repairs, exterior; Rep. Gr.63. –  Move lock carrier into its service position → General body repairs, exterior; Rep. Gr.50.

–  Pull off engine cover panel -arrows-.   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 together with engine lifting eye.

–  Remove cap for toothed belt cover (top section).   Note The types of toothed belt cover (top section) differ depending on version.   Caution The engine must only be turned at the crankshaft, in the direction of normal engine rotation (clockwise). –  Rotate crankshaft to TDC by turning central bolt for toothed belt sprocket. l  Marking on camshaft sprocket and marking on crankshaft must be aligned to TDC -arrows-.

–  Unbolt vibration damper; counterhold on centre bolt with ring spanner.

–  Remove toothed belt cover (top section) -arrows-.

–  Remove toothed belt cover (bottom) -arrows-. –  Mark direction of rotation of toothed belt with chalk or felt pen. –  Loosen tensioning roller and remove toothed belt.

Installing (adjusting valve timing)   Note When turning the camshaft, the crankshaft must not be at TDC. Otherwise, there is a risk of damage to valves and piston crowns. –  Fit toothed belt onto crankshaft sprocket, noting direction of rotation. –  Install toothed belt cover (bottom) -arrows-.

–  Install vibration damper with new bolt.

–  Align markings on camshaft sprocket / toothed belt cover (rear) and markings on vibration damper / toothed belt cover (bottom) -arrows-.

–  Fit the toothed belt to tensioning roller, camshaft sprocket, sprocket for coolant pump and finally to idler roller -arrow-.   Note

Check that tensioning roller is seated correctly in cylinder head -arrow-.

–  Adjust toothed belt tension as follows: –  Use hexagon key to turn eccentric adjuster of tensioning roller clockwise -arrow- until the notch is above the indicator. –  Then release tension on toothed belt. –  Now tension toothed belt until the notch and the indicator are aligned. –  Hold tensioning roller in this position and tighten tensioning roller nut to 25 Nm.   Caution The engine must only be turned at the crankshaft, in the direction of normal engine rotation (clockwise).

–  Turn crankshaft two rotations via central bolt for toothed belt sprocket until it is positioned at TDC again. l  Make sure that the engine is rotated without stopping during the final 45° (1/8 turn) of the crankshaft. –  Check valve timing again: l  Marking on camshaft sprocket and marking on crankshaft must be aligned to TDC -arrows-. –  Check toothed belt tension again. l  Indicator should align with notch on tensioning roller. If the markings do not align: –  Repeat adjustment of valve timing.

If the markings align: –  Install toothed belt cover (top section) and tighten the bolts -arrows-.

–  Install tensioner for poly V-belt together with engine lifting eye -arrows-. Remaining installation steps are carried out in reverse sequence; note the following: –  Install poly V-belt → Chapter. –  Install lock carrier with attachments → General body repairs, exterior; Rep. Gr.50. –  Install front bumper cover → General body repairs, exterior; Rep. Gr.63. Tightening torques

Component	Nm
Tensioning roller to cylinder head	23
Toothed belt cover (bottom) to cylinder block	10 1)
Vibration damper to toothed belt sprocket	10 + 90° 2)3)
Toothed belt cover (top section) to cylinder head	10
Tensioner for poly V-belt to bracket for ancillaries	23
l  1) Install using locking fluid; for locking fluid refer to → Parts catalogue. l  2) Renew bolts. l  3) 90° = one quarter turn.