just go to a place thats a decent parts house and ask to get a hand full of them and try them till you find one that fits, assuming you have brought the one thats on the radiator now in to the store for them to compare it to


also does the cap have any numbers/markings on it?

any idea who makes the radiator? it should have a part # on it somewhere

This post was edited by KoJ on Jul 26 2016 03:27pm

If the cap isn't sealing you won't have enough pressure to raise the boiling point of the antifreeze to where it needs to be.

Yeah; the cap itself doesn't have any kind of serial number or markings on it. This last trip to O'Reilly's, I took the cap with me. Tried to eyeball what I thought was a cap that fit, but no dice.

I'll have to get in there to see if I can find the make of the radiator.


Did not know that; good to know. Definitely want to eliminate the cheap and obvious problems first, before pulling the trigger on a new water pump.

if worse comes to worst, a new radiator is like $100

This post was edited by t9x on Jul 27 2016 10:38am

i think water pump can safely be ruled out at this point at least until you fix your radiator cap situation and see if that solves your problem or not. the way cooling systems work is they pressurize and as the pressure goes up it raises the boiling point of your coolant like fmx said. if you dont have a good seat you arent pressurizing your system so not only does it boil at a lower temp your cap that isnt sealing is letting that boiling coolant push right past it.

more than likely that cap is your only problem. and like t9x said if nothing else get a new radiator for it with a cap that will actually work.