Audi Workshop Service and Repair Manuals

Removing, installing and checking thermostat Special tools and workshop equipment required

t  Pin wrench -3212-

t  Locking pin -T40011- Removing l  Lock carrier must be in service position → Chapter. –  Drain off coolant → Chapter. –  Remove poly V-belt → Chapter.

–  Unscrew bolt -arrow- and remove tensioner for poly V-belt.

–  Unbolt poly V-belt pulley at power steering pump -arrows-, using pin wrench -3212- as a counterhold.

–  Remove covers for cylinder head cover (left and right) -arrows-. –  Remove toothed belt cover (left and right). –  Remove crankshaft pulley → Chapter.

–  Release retainers -1- and -2- and unscrew bolts -4- and -5-.   Note Bolts -item 3- must not be slackened. –  Take off bottom sections of toothed belt cover.   Note The toothed belt tensioner is oil-damped and can therefore only be compressed slowly by applying constant pressure.

–  Turn toothed belt tensioning roller -1- clockwise in direction of -arrow- using an 8 mm Allen key until tensioning lever -2- compresses tensioner -3- far enough for the pressure piston to be locked with locking pin -T40011-. –  Insert locking pin -T40011- and release toothed belt tensioning roller.

–  Pull toothed belt forwards slightly on tensioning roller and right camshaft sprocket -arrows-, but do not pull off completely.   Caution Timing must be re-adjusted if toothed belt has slipped off tensioning roller → Anchor. Follow all instructions for removing and installing toothed belt → Chapter.

–  Detach coolant hoses -1- and -5- from thermostat housing. –  Unscrew bolts -2-, -3- and -4- and detach thermostat housing. –  Remove O-ring and thermostat. Installing Installation is carried out in the reverse order; note the following:   Note Renew O-ring. –  Before installing, clean and smoothen sealing surface for O-ring. –  Install thermostat.

l  Installation position: vent valve -arrow- faces upwards and seal faces to housing. –  Install thermostat housing.   Caution Timing must be re-adjusted if toothed belt has slipped off tensioning roller → Anchor. Follow all instructions for removing and installing toothed belt → Chapter.

–  Using an 8 mm Allen key, turn toothed belt tensioning roller -1- clockwise in direction of -arrow- until the locking pin -T40011- can be removed. –  Proceed as follows to pre-tension tensioning roller before first starting engine: –  Apply torque wrench to hexagon socket on tensioning roller. –  Tension belt by applying a torque of 15 Nm to the tensioning roller. This provides the correct amount of initial tension. –  Install crankshaft pulley → Chapter. –  Install poly V-belt → Anchor. –  Install lock carrier → Chapter. –  Fill cooling system → Anchor. Tightening torque

Component	Nm
Thermostat housing to cylinder block	10