OVER HEATING on 1998 Ford Mustang GT

IN TRAFFIC MY CAR OVERHEATS. I TURN THE A/C OFF AND HEAT ON TO MAKE TEMP COME BACK DOWN. DOES NOT OVER HEAT AT IDLE. COOLANT SEEMS TO BE COMING OUT OF THE RADIATOR CAP AS SOON AS I START THE CAR. THE COOLANT FAN IS TURNING ON, SO IM THINKING THE THERMOSTAT IS STICKING....HELP

Asked by for the 1998 Ford Mustang GT
first of all. stop driving the car till you get it fixed. the fact that you have overheated numerous times may have compouded the problem. you need to have a dye put in system to check the leak. then a hydrocarbon test for internal engine damage. after these tests are done, then we can discuss a course of action for a proper repair.

Roy