Audi Workshop Service and Repair Manuals

Removing, installing and checking thermostat

Removing –  Unclip cover caps. –  Unscrew nuts -arrows- and detach engine cover panel. Also pull out dipstick if necessary. –  Remove insulation beneath cover panel (if fitted). –  Drain off coolant → Chapter.

–  Disconnect coolant hose from hose connection for thermostat -arrow-.

–  Remove securing bolts -1- for hose connection -2- and remove hose connection together with thermostat -4- and O-ring -3-.

–  Turn thermostat -item 2- approx. 90° (1/4 turn) anti-clockwise -arrow- and remove it from hose connection. –  Remove O-ring -1-. Installing Installation is carried out in the reverse order; note the following:   Note Renew O-ring. –  Clean and smoothen sealing surface for O-ring as required.

–  Insert thermostat -3- with new O-ring -2- into hose connection -1-. l  When inserting, the cross-piece on the thermostat should be horizontal as shown in the illustration. –  Then turn thermostat 90° (1/4 of a turn) clockwise. –  Lubricate O-ring with coolant additive. –  Fill cooling system → Anchor. Tightening torque

Component	Nm
Hose connection for thermostat to cylinder block	15

Checking thermostat –  Heat thermostat in water bath.

Starts to open	Fully open	Opening travel
approx. 87 °C	approx. 102 °C 1)	at least 8 mm
l  1) Cannot be tested.