its reading hot and the heat warning sing its on,,,, with the engine on the left fan its not spinning,,, but the right one its working ,, i don't know the difference
I own 2000 Audi A4 (same engine / tranny as yours).
Our cars have a known bad water temp sensor problem. If your car is reporting high temp but is NOT over heating (boil over), then it might be just water temp sensor.
The sensor part is very cheap (less than $15 at the dealer). The repair is simple. Go to Autozone.com and look up the car repair manual (free).