A4 Faulty Water Temp Gauge

Most likely someone has removed the connector from the sensor and forgot to replace it. Or the sensor has failed. If I recall correctly it's on the right of the engine towards the rear. Just look for a loose connection or a cut wire!

I'll take a look thanks, any other advice gratefully received!

From discussion on the more specialist / technically orientated Audi web-sites, it would appear that the temp sender on 80's and the like are regarded as being suspect. It would be fair to assume that the problem may well apply to later models as well.

Apart from the obvious (but perhaps unlikely) loose/cut wires, the only other checks you can make are to wiggle the plug and see if that helps. Certainly on my car (an old 80 with a similar problem) I eventually found the correct sender (grey - 3 pin) and eventually identified three wires below the rubber cap on the plug - one was obviously an earth as it gave no reading on a circuit tester - another gave a steady pulse (no idea what for) and the third gave a steady reading. On earthing that one, the temp gauge ran to red - which proved the gauge worked, although I suspect it may be "sticky" - another known problem apparently.

You could try this - but don't blame me if you blow something expensive! I'd pop into the local Audi dealer and ask nicely if someone can spare 10 mins to put their gauge-tester on it - that at least will help identify whether its the gauge or the sender. If its the sender, and if it's the same set-up as the 80, it's a 30 second job (no tools) to change. £25 or so for the sender though.

Best of luck - I'd be interested in knowing how you get on.

Mike.

Mike,

Thanks for the advice, I'll post the result as soon as I have time to get the car to the garage!!!