HOW THE **** DID THE CAR START AND RUN, AND WHY CUT OUT ALL OF A SUDDEN
The engine is constantly moving, especially if he was hitting gears, i have had the maf wiring fall off, bpv slipping off etc, you would be surprised. Since the check engine light is not coming on even with the keys turned to acc. then I think that would indicate that something electrical is screwed. So even when the car has not been started, as soon as you put in the key the temp goes to max? It must be electrical or something to do with your thermostat if it was mechanical I would think, until you figure it out this whole thread posting war is a waste.