this one's got me confused...headgasket, water pump, thermostat and radiator cap has been replaced but the car is overheating only when i'm driving uphill or so it seems...the reservoir bottle is filling up with coolant...no signs of leaking anywhere...the only thing I haven't changed is the radiator...fan is turning on and the radiator hose are warm so i can tell the coolant is circulating...others have suggested that the radiator might have a clog on it...i highly suspect the radiator more so now that i noticed that it was a different style radiator cap...coz i had to buy the older style of radiator caps from an EF radiator...what do you guys think?