ok i gotta 2001 a4 quattro 2.8 30v....its got 77k on the clock and just recently my temperature guage started not workin intermittently...cant find a constant as to when it stops workin or starts again....but i did notice this, when the car is runnin it registers full cold but it does lift a lil tiny tiny bit from when the car is off and no power is goin to it......any ideas on what this can be? im hoping its not the cluster cuz i dont wanna have to go thru all that....please some1 out there tell me they had this problem and it was just the temp sensor or something?

 

Most likly its a faulty coolant temp sensor. Very common failure. Dont think ive every see a problem with the cluster as far as the engine temp is concerned.

 

but wouldnt that have thrown a code and a check engine light? ...

 

Does the oil get up to temp? Just because the coolant temp is bouncing around or off doesn't mean it will throw a CEL.

 

i have a 2001 1.8t it does the same thing drops then goes back to the middle then drops again. my friend has a 2000 a6 2.7t his does the same thing its np i think but i wanna know what could go wrong. its not the sensor because if it waas then it would never move from cold but it does then it drops for no reason after driving for a while

 

this is happening to me, im thinking it cant be the temp sensor if u check the value your temperature sensor is reading (by using secret codes on climate control) it most likey will be the correct temperature, so if the climate control is showing correct temperature doesnt that mean the sensor is working fine?

 

i have the same thing with no cel.sensor time.sp33 why are you making fun of other peoples audi's.

 

air lock bleed the system properly

 

there are seperate sensors. Engine coolant temp sensor and engine coolant temp sender. The sender is what sends the signal to the gauge. I beleave it is like this in the 01 I know in 98 it was. Anyway I will see if I can locate the diagram. Though I have run into bad gauges and you can replace just the gauge.

 

Signal From Engine Coolant Temperature (ECT) Sensor -G2-, Checking

If a malfunction of the Engine Coolant Temperature (ECT) gauge is detected at the instrument cluster, check if the signal at the instrument cluster is OK.


Connect VAS5051 tester or VAG1551 scan tool. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks" under "Lighting and Horns"
Read Measuring Value Block. Refer to "Scan tool Testing/Measuring Value Blocks (Function 08)/Reading" under "Instrument Panel"
Select display group number 003.
If the Engine Coolant Temperature (ECT) appears on the VAG1551 scan tool display but not by the Engine Coolant Temperature (ECT) gauge, the instrument cluster is faulty and must be replaced.

If no Engine Coolant Temperature (ECT) is indicated on the VAG1551 scan tool display, the signal must be checked at multi-function connection at instrument cluster.


Remove instrument cluster.
Connect VAG1598 tester with VAG1598/25 adapter to the blue 32-pin connector.
Measure resistance (sensor resistance) between terminal 8 and 7 using VAG1526 multimeter.
Specified values:
Coolant temperature 90 °C : approx. 110 Ohms
Coolant temperature 120 °C : approx. 50 Ohms

If the specified values are not reached, the wire connection to Engine Coolant Temperature (ECT) -G2- must be checked.


Check wire connection according to wiring diagram.
If the wire connection is OK, Engine Coolant Temperature (ECT) -G2- must be replaced.