Hey.
I recently bought an Audi A6 Avant 2.4 Quattro 2003 (170hp) with 140000km, and as most of the used cars it had some issues.
The water temp gauge almost every time stays at below 60 degrees. All other gauges works just fine. The fuel economy is what i would call insanely high. I ran mostly on the highway and it consumed around 14L/100km, and I tried to drive as eco as possible. I checked channel 51 on the climate control this morning and the starting value was 76 and it ended up in 122 (degrees?)
Is those temp values normal? Can they make the engine use more fuel or is the consumption normal for this car/engine?

Thanks!

 

Yes. A faulty thermostat / bad temperature sensors will essentially tell the ECU that the engine is still cold and to supply it with more fuel because of this "cool" condition. The ECU never gets the "Ok" from the temp sensors to lean out the fuel/air mixture so it will continue to burn excess fuel until this condition is fixed.