1999 F250 7.3 liter heater core

[JayCarotenuti]

At 100K miles my heater core went out. Easy enough to change. I bought one from ford, installed it worked fine for about 4 days. It started leaking again. I took it out and went back to ford dealer. They gave me another. Same thing happened. About 3 days. Going on the 3rd one. Same story. Getting tired of replacing it. Is it just a cheap core or what? Any suggestions. Is there a better one aftermarket?

[lancer]

Are they leaking in the same spot? Make sure that there is nothing sticking into the heater box and puncturing them.Good luck and merry christmas!!

[99Smokin73Stroker]

Welcome to powerstrokeforum.com Jay! Good to have you here. I'm not sure what could be causing that. It could be just bad luck on each part by some weird circumstance...or it could be something on your end that you're missing with each swap. Maybe get some advice from the dealer.

[overl0rd]

There is a TSB about repeat heater core failures, a condition called electrolysis. Apparently there is an ion exchange between the coolant and heater core and that will eat through it. To check, hook the negative side of a multimeter set to DC volts to the negative battery terminal and stick the positive lead in the coolant. Run the engine at 2 grand. If it measures more than .4 volts there is electrolysis. Flush the cooling system and recheck. If its still there, check all grounds and retest. If its still there add extra grounds to the heater core and engine, using EXISTING FASTENERS. If its still there add a restrictor in the (part F1UZ-18D406-A) on the inlet hose with the arrow in the direction of coolant flow. It is important the restrictor be installed in the direction of coolant flow and as close to the engine block as possible.
Oasis codes 208000, 208999, 402000

[99Smokin73Stroker]

Geez......imagine the chances! Wierd things happen!

[JayCarotenuti]

Thank you very much for that info. I have been working on vehicles for years and never heard of such a thing. I will try this out. I have gotten real good at changing this thing now. If I could get the clips off the end of the tube easier I could do the whole job in 10 minutes, Any suggestions to getting the clips unhooked.

Thanks again