Franny's TDI Passat started to run hot on her Wednesday. Luckily, it has more than an idiot light . . . when it gets hot an alarm goes off and a big STOP lights up on the instrment cluster. She stopped and let it cool off then took it to the local service station (yes, we have a real service station in LaFayette . . . they will pump your gas and wash your windshield and everything). Their mechanic looked and said the fan clutch was bad. They got her an aftermarket one from O'Rielly's and installed it yesterday. The clutch was bad . . . it looked like the fan was about to fly off the hub. But, that didn't fix the problem. Today I took Liv to school (about 10 miles) and it did OK going, but about 2 miles into the return trip the alarm went off and the STOP lit up again. I stopped and let it cool, took off again and made it a couple of miles before the gage started getting close to the red . . . let it cool, went a couple of mile . . . let it cool, etc. Finally made it home. The coolant level is OK. Nothing appears to be leaking. When I took the coolant cap off it boiled over a little then stopped. Now the coolant level looked slightly over the MAX level.
What should I check next? Thermostat maybe? Or should I just take it in to the dealership and have them go over it. I don't much about Diesles, and the LAST thing I want to do is damage this engine!