Desperate Dan

Hi, I had exact same fault with mine. My temp sensor wasn't reaching op temp of 90c, even after new stat fitted. I had a slight coolant loss which I traced to rear coolant sensor on back of head. Took old sensor to motor factors (so as to buy correct sensor) and was informed that my sensor wasn't the correct one. Apparently they are colour coded, my one was grey when it should have been black. Fitted new black sensor (supplied with strong metal spring clip and not cheap black plastic one) bled coolant system and took for test drive.....The difference was night and day. Smooth rapid pick up, no lag/flat spot and most importantly temp gauge reached 90c with 10/15 mins of driving. I now don't suffer from what people think is regenning, revs increasing to 1000rpm and cooling fans coming on. That was engine ecu being told engine was cold by incorrect sensor and was over fuelling to increase temperature. Check the colour of your rear sensor, it could be just that simple a fix. My sensor cost me £14.50 from Europarts....nearly snapped my index finger fitting the metal clip though....it has never run so smoothly and used the least amount of fuel if now does or doesn't !!!!

110K... You could be looking at a worn or faulty torque convertor, especially if it stalls when cold. Rather than go back to Audi at £190 an hr, find a Transmission/Gear box specialist and take it there for diagnosis. These guys strip down auto boxes all day everyday and will be very knowledgeable and cheaper than Audi Main dealers. Let us know what the result is, good luck.

What mileage has your car covered???

"the dealer says that this is a problem affecting a very small number of this model and that Audi are working on, but do not have a software fix yet but when they have they will sort it." I'd say that's common dealership talk for, we know there's an issue but haven't found the cause yet. Some dealerships farm out electrical faults to smaller independent dealer trained specialist workshops. That might be worth a look, and if it can be rectified by one ask the dealership if they will contribute towards the cost of repairs.

Good point made by Magnet, obviously the Audi Tech didn't road test your car after oil and filter change. That's where dealerships fall down with everything done on the clock....time is money. Didn't you notice the fault after you'd collected the car from the dealer?

Hi, I had a similar fault on an A4 2.0 TDI 2003, I eventually traced it to a faulty Alternator clutch pulley which was seized. The car had been in storage for over a year on blocks. The steering was very heavy and lumpy , checked steering pump, cooling fan bearing and once serpentine belt was removed I could feel how notchy the alternator pulley was when spinning it. Bought a new one and replaced it and instant smoothness returned....so many variables to choose from. But as always we jump in with both feet and go for the most expensive fault we think it might be.