my supra for some odd reason, when i warms up it sends the coolant back to the resevior and it starts to overfill and my engine gets really close to overheating. i flushed the system and washed it dry. then replace the thermostat and got a new o ring and gasket for it. refilled with new coolant and still the problem came back.. note that the resevior is shooting coolant back into the resevior, all of it. after all coolant has reached the resevior, then nothing but hot air shooting into resevior. please help.. this is all i need to fix then the car is ready to drive again..