ORIGINAL: chelle26

check this one, http://www.aa1car.com/library/overheat.htm
Engine overheating problem might be from radiator cap and the pressure it holds. If the radiator cap does not hold pressure correctly then coolant could boil and therefore the engine would overheat. Another reason might be caused by thermostat failures; it is recommendable that you check. And coolant leaks such as those from the porsche radiator, the hoses, the water pump, the freeze plugs or any others. Also, problems in the water pump could be the cause and therefore you should check it and replace it in case it is needed.