Audi Workshop Service and Repair Manuals

Checking map-controlled engine cooling thermostat -F265-

Special tools and workshop equipment required

t	Hand-held multimeter -V.A.G 1526 B-

t	Auxiliary measuring set -V.A.G 1594 C-

t	CLIC hose clip pliers -V.A.G 1723-

Test condition l  Engine cold Testing internal resistance of heating element –  Pull off engine cover panel -arrows-.

–  Unbolt coolant expansion tank -arrow-. –  Unplug electrical connector for coolant shortage indicator switch -F66- at expansion tank (bottom) and move expansion tank to one side (coolant hoses -1 ... 3- remain attached).

–  Unplug electrical connectors at intake manifold pressure sender -G71--item 1- and intake manifold flap air flow control valve -N156--item 2- from front of intake manifold.

–  Release hose clips at connections -arrows- using CLIC hose clip pliers -V.A.G 1723-.

–  Remove bolts -2- and -3- and detach throttle valve module -J338- from intake manifold. –  Detach vacuum hose -5- at intake manifold. –  Unscrew nuts -1- and -4-. –  Detach intake manifold from flanges.   Note Block off intake ports in cylinder head with clean cloths.

–  Unplug connector -5- at map-controlled engine cooling thermostat -F265-.   Note Disregard -items 1 ... 4-. –  Connect multimeter to thermostat to measure resistance. l  Specification: 14 ... 16 Ω at 25°C. If specification is not obtained: –  Renew thermostat → Chapter.

Function test of thermostat –  Remove map-controlled engine cooling thermostat -F265- → Chapter. –  Check the thermostat when cold. l  The large valve head -arrow- must seal off the connection flange all the way round. If not: –  Renew thermostat → Chapter.

–  Connect the contacts of the thermostat with a battery using test leads from -V.A.G 1594 C-. –  Using pliers, carefully place the thermostat vertically into a pot of boiling water up to the flange.   Note t  The electric heating element now additionally heats the wax in the thermostat. t  Do not expose the thermostat to air during this test, otherwise the expansion element can become damaged. –  Check whether the minimum travel of -a- = 7 mm is attained after 10 minutes. If minimum travel is attained: –  Disconnect voltage supply from battery. If the minimum travel is not attained: –  Renew thermostat → Chapter.

Assembling Installation is carried out in the reverse order; note the following:   Note t  Renew gaskets and seals. t  Secure all hose connections with the correct type of hose clips (same as original equipment) → Parts catalogue. –  Slip intake manifold onto connecting hoses. –  Secure hose clips at connections using CLIC hose clip pliers -V.A.G 1723-. –  Interrogate and, if necessary, erase the fault memory for the engine control unit, as faults are stored when the connector is unplugged → Vehicle diagnosis, testing and information system VAS 5051. Tightening torques

Component	Nm
Intake manifold to bracket	20
Throttle valve module -J338- to intake manifold	10