I hope someone has a simple answer to this problem.
My brother just got a 1994 TT Soarer. Now after a nice cruise, he'll pull into the driveway, go over a dip (not sure if this is part of the problem) and then the temp guage will jump from 1/2 (where it should be) up to full and make warning beeping noises. Then all of a sudden, it will drop back down to half. Sometimes it stays up on full for a while.
My brother was concerned that his car was overheating but I assumed it may just be a faulty temperature sensor or wiring for the the sensor as I didn't think it possible for a car to increase its heat this fast while at about 1000rpm pulling into a carpark. It has all new fluids.
Does this sound right or should he have the car looked at?