Temp gauge/cooling problem

[harrier22]

Hi all.

I've just found this forum and it looks like a fountain of knowledge so hopefully someone can help me out. I have acquired a 1992 Audi 80 2.0E with 170,000 on the clock and am having a problem with engine cooling. The temp gauge never rises to the normal level and I have also noticed that the coolant in the expansion tank remains cool, even after a run. I am hoping it is not anything to do with the thermostat as it looks like a tricky job to replace. Does this sound familiar to anyone? Any advice/comment gratefully received.

[brd]

Just off the top of my head, I'd be thinking the thermostat is stuck open and thats why its running cool. Are the fans ever coming on?
The thermostat itself is cheap enough... I haven't looked to see where it is yet though.
Another possibility if the temperature sender in the back side of the radiator is faulty and giving a wrong reading... thats even easier to change (without even draining the coolant).

[harrier22]

Thanks for your suggestion, brd. I know what you mean about the thermostat sticking open but the coolant in the expansion tank remains almost cold whilst the water hoses get hot. I don't know if I'm missing something glaringly obvious.

[brd]

Ah... sorry... you mentioned that. You know, I think I had a similar problem with a 1993 80 a few years back... and there was in fact no problem... just the gauge was not reading right. The temp sender (if faulty) is mounted on a water pipe near the middle of the engine bay to one side of the rocker cover - blue one is for gauge and brown one is for engine management I believe. They only cost a few quid and are dead easy to change - only do it when engine is cold, as coolant will come out otherwise - and release pressure in the system (if any) by releasing the reserve cap for the coolant.
Brd.