2004 A8 Temp light and fans

[Columbus_SB]

My temperature warning just started coming on today. I've had other warning lights come on and usually just turn off the car and start it again and many times it resets and goes away. However this seems strange because a bunch of engine fans seem to come on immediatly, without even starting the car. I don't remember hearing those before. Also the gauge never shows that the engine is warming up. Sound like a faulty temperature sensor? If so is that something I can do myself...being an old backyard mechanic.

Thanks!

[smokey0123]

A fault code read on the engine management and instument cluster would be a good start to point you in the right direction.

I would guess coolant temp sensor as well tho, it sounds to me like it intermittantly open curcuit.

[a8 tech]

fan control unit defective its part of the fan

[Columbus_SB]

Thanks for the quick replies. Couple of questions - do you think it drivable for a few days or at least to get home? Since I'll not be able to tell if it overheats. Anything I can replace myself or just take it to the shop?

Thanks again.

[Columbus_SB]

Deffinately seems to be a switch gone bad. All cooling fans seem to fire up immediately with just the key on / engine not on. Got home OK last night and the temp guage never budged. So I'll park it until Monday when I can get it to my shop. Also ordered a service manual from AutoHausAZ.com

AU8058305 Repair Manuals - CD Rom Versions; 2004-2007 A8, S8; OE Factory Authorized - $66.99

If i'm going to keep this car I might as well see if I can do a few repairs myself.

Thanks!

[Columbus_SB]

Followup - my tech hooked up the computer to read the error code but could not diagnose the problem. He went ahead and cleare the code and the problem went a way. Radiator fans returned to normal function, thermo guage began functioning, etc.

Guess another false positive - which I've had several of with this car.

Thanks!

[a8w12]

Hi Did you have any further problems with the temp light and fans. Mine has done the same thing a couple of times. Looks like a faulty Coolent temp sensor. Thanks

[Columbus_SB]

Yes it happend another time. According to my mechanic the fans coming on are a failsafe mode. It was a couple of years ago but this time i think we had to changed a sensor. Don't think it was too expensive (as Audi repairs go...if you know what I mean).

Good luck!

[a8w12]

Many thanks, its an A8 W12 so I definantly want look after it, I think I will change the coolent sensor Its cheep part anyway,
Cheers David, Scotland UK