You have an overheating problem it's not the radiator or the thermostat?

You say it's not the radiator, but when coolant in radiators is not flushed out at service intervals, corrosion can occur inside the radiator, diminishing coolant flow. This would present as overheating, especially in the summer months. Radiator flush/cleaing services are sold at Jiffy-Lube, etc, but you can get the same chemical packets at Pep Boys, NAPA, etc. Good Luck Also: check to see if you have water coming in your passenger side. Check the floor for wetness, and if it smells like antifreeze. This is your heater core gone bad Defective water pump, fan, fan clutch if equipped, fan thermal relay.