Ill try and keep a long story short... Basically, about 5 months ago my dash temp gauge was playing up a bit, taking longer than normal to get to 90˚ (if at all), then on faster journeys (motorways) it would dip, then when sitting in traffic it would go back up again. Previous to this it would get to 90˚ and would stay there. After doing a bit of research it pointed to a faulty thermostat. So took it to the garage (Audi specialist) who said its unlikely to be the thermostat and did a few tests and according to the 'laptop' it was ok, and said that it isnt unordinary for the gauge to do this (not according to my research!) So left with the same problem. Still not happy with it, I took it back and asked for it to be changed anyway. So thermostat was replaced, left and everything was perfect getting to temp ok and staying there. Phew! Until a couple of weeks ago, the problem came back. Took it back, once again the 'laptop' says its ok, and was told that it could possibly be a faulty gauge, which would require a new dash costing about £400! Now after more research the symptoms certainly dont seem to point to a faulty dash? I think it must be another faulty thermostat. Can anyone give me some advice, or may have some knowledge on this? I dont really fancy having to take it to another garage and having to pay £££s for someone else to look at it, when Ive already paid for it to be sorted. I've also tried the climate control 49 temp display trick. When on the motorway displays mid 70's, in traffic and stationery anywhere between 80-90. Basically follows a similar habit as the gauge, although the numbers are slighly different. Just out of interest what should be at? Any advice or help would be much appreciated. Cheers Ps had the coolant sensor replaced a couple of months ago, and the water pump is only a couple of years old if this helps?!