:confused: TRUCK HAS BEEN GETTING HOT (BIG SURPRISE IN 110 DEGREE PHOENIX) SO I DECIDED TO BUY A THERMOSTAT. ON THE WAY HOME, RPM'S STARTING SURGING UP AND DOWN ON THE FREEWAY. STOPPED AT A STOP LIGHT AND TRIED TO GO BUT TRUCK JUST STOOD STILL LIKE IN NEUTRAL. I FINALLY GOT IT GOING AT MAX...