Heater core blowout!!

[Power By Ford 70 F250 4x4]

I had a new good quality heater core and tested the 13lb cap all was good. I drove the truck for an hour, parked at a truck show after a whole day sitting I started out to head home. I got about a mile down the road when it blew. I took it out and it was swelled as if someone put a 150lbs.of pressure on it. I took it to local radiator shops. No one has ever seen anything like it. The temperature gauge never went passed half. Anybody ever see this happen?

[jzjames]

Was it a $30 heater core from Oreilly's and there might have been a manufacturing defect?

For it to blow up like that there must have been some kind of blockage.

[flyboy2610]

For it to blow up like that there must have been some kind of blockage.

That would be my guess.

[Russell J]

Would a stuck thermostat cause that kind of pressure build up? Just taking guesses here...

[Wilfred of Ivanhoe]

I have had a similar issue happen to me twice. Once it did not blow, but id did swell up quite a lot. I only discovered it when I was checking something else. The other time, ...I may have been revving the engine a bit when there was an eruption of steamy green water from under my dash. My passenger freaked out a bit.

At any rate, I believe these heater core blowouts are due to low quality parts, operator issues, or a combination of both. Just my thoughts.

[Ren]

If the thermostat was stuck shut, the engine would get hot too. I doubt it was caused by a blockage. The only things I can think of are a heavier than normal radiator cap, or maybe the metal of the heater core was too thin (cheap). Those crafty, wiley Chinese are always finding ways to pinch a penny.

[Power By Ford 70 F250 4x4]

Thanks for all the input. After talking with many radiator repair shops and mechanics my conclusion is that there are only two ways this could have happened #1 it had over 200 psi or #2 it had froze. Seeing how it would be impossible to build that kind of pressure it had to have froze. There were times during this build that I used straight water so as to not waste antifreeze. So I'm thinking because there is an in line valve for the heater core water may have been trapped in the core .I have never used the heat so possibly it never circulated in with the new antifreeze. That's the best I can conclude. Just odd that it took so long to finally let go.