2006 Pontiac grand prix super charged over heats time to time. Coolant gets low in radiator but ful in resovior and car says turn off air conditioner and then cools off .

Loosing antifreeze coolant,can,t find any leaks,fluid is going out somewhere,try looking at your intake gasket,may have small leak,with motor warm you would never see,allso if your car may have a little sput now and then check your exhaust for leakeage of excessive water loss.Could mean you have head gasket leak.