my car keeps overheating please help

my car cant stop overheating. sometimes it runs good then sometimes it dont wanna stop overheating. last night i had to keep refilling the radiator. i dont think theres a hole in the radiator. is there something else it can be that keeps making my car overheat. my fan does work i check it last night. could it be the thermostat??????//

my car cant stop overheating. sometimes it runs good then sometimes it dont wanna stop overheating. last night i had to keep refilling the radiator. i dont think theres a hole in the radiator. is there something else it can be that keeps making my car overheat. my fan does work i check it last night. could it be the thermostat??????

you had to keep refilling you say? only does it some times you say? there's got to be a hole, otherwise you wouldn't have to keep refilling it.
thats also got to be the reason why it only happens sometimes, because once you refill it then it doesn't over heat and once it starts running out it begins to over heat. i had the same prob.

When was the last time the water pump was changed? It needs to be changed every 90K miles. It will leak soon after 90K.