JDM_Silver

Hey everyone.. I need some help with my radiator problem once again.. Hopefully its somethign small... but here it goes.. AWhile back my car was overheating 3/4 of the way up while i was idling on the streets, as soon as i drove off it would go down.. ANd during that time i guess my car needed a new thermostat. SO i went to get a thermostat put on.. but its still overheating.. The fan is working, but when it turns on it heats up.. So what im asking.. Could it be a wrong thermostat? is it slightly opening up but not all the way?? It never overheated on me on the freeway only when im driving local streets. im not leaking any fluids of any kind... and it seems like the reserve tank is always overflowing with coolant, and when i open up the radiator cap its not all the way full.. so i dump the excess coolant into the radiator and it goes right back to the reserve tank..... SO please help me guys.. Hopefully it is the thermostat.... or something small.... Please help asap


thank you!