Engine Cooling problem
1993 Mercury Sable 6 cyl Two Wheel Drive Automatic
Whenever I pull up to a red light or go through a Drive-Thru, my car starts to overheat. It happens really fast whether I have been driving around all day or just got in the car. I can literally watch the guage go up as I sit with my foot on the brake and the car in Drive. As soon as I take my car off the brake and start going, it starts to come down. My mechanic had to tighten all the clamps on my hoses because I had a small leak and he even did a pressure test to be sure that there wasn't a leak inside the engine. I checked the coolant overflow tank and it is full. Does anyone know what the problem could be? Should I have the thermostat changed?