I have a 2001 ford f250 super duty with a 5.4 triton roughly 220,000 miles but the truck runs sweet no issues except i keep blowing heater cores . Im on my 8th heater core in 2 years roughly it blows every 3 month's . I have replaced the heater core / heater core hoses /thermostat / water pump / radiator cap / upper and lower radiator hoses / flush radiator several times /replaced all of the foam around the heater core / i have made sure that it doesnt move around / i also have been very carfule to not ben or puncture the fins on the core . Im banging my head against a wall on this one and i need help ? . After i install a core the heater always works like a champ until it just blows up and covers the windshield. Any help would be much appreciated

 

Hmmmm...assuming you are using the correct psi radiator cap, my next swag would be the mfg of the heater core...if you are buying them from one of the auto parts chain stores, well, I hate to say it, but that's the issue- quality control. If not, then I would look at getting a "certified" radiator cap (they are much more precise in their ratings and control) and then look at the radiator for internal partial obstruction and the lower radiator hose for partial collapse potential that may be causing excess psi build-up thus exceeding the design specs of the heater core.

 

i purchased 2 oem caps i believe they are 16 psi .
and i purchased all of the cores from advanced auto and i believe they are the spectra brand . All of the cores have leaked in either the upper left or upper right corners . I dont kniw how much it helps but sometimes at idle the temp drops a little until i tap the gas then it gets super hot again . And occasionally i could hear gurgling from the heater core. The other strange thing i noticed is i can drive for miles and miles and still be able to take the radiator cap off without the fluid trying to rush out? when hot i can squeeze both upper and lower hoses and i can feel pressure .
i replaced the lower radiator hose recently and ididnt notice the hose doing anything strange while i was watching it for leaks. I even thought maybe it had air in the system so i purged all the air and i noticed the heater would get a little hotter