Anyone know how to keep from blowing heater cores?

Has anybody got any suggestions to prevent the heater cores from spliting...short of not driving the car?

I have my 90 'Bird apart right now, and I have had the same problem on my 84 Mustang...(changed that %@#&^@! 4 times).

Both cars have done the same thing, the cores are swelled and eventually split at a seam on the inlet side.

It seems like there is too much pressure there.

I have done this job 4 times on the Mustang and this is #2 on the Bird....I'd really rather have a root canal than do this job again!

To all minds greater than mine....a little help.....please.

Be sure you buy a top quality name brand heater core- a cheap price isn't worth it when you have to keep replacing them! With the engine running, connect the negitive (-) lead of a voltmeter to the negative terminal of the battery and insert the positive (+) lead into the coolant. The best reading is 0VDC but anything over 0.3VDC will lead to pinholes in the heater core in a short time. When you change the heater core be sure to use a good quaulity flush and neutralizer before adding new antifreeze.Be sure you have all of the original ground straps between the body, engine, chassis and battery connected and they are clean and tight. One last thing to check is the pressure cap on the radiator. Be sure it is the correct rated pressure for your car.

It's not electrolysis. The radiator cap is correct and new.

I think it's an excess flow pressure issue.

As far as brand names, all the times I bought on there was no choice of brands. What ever Pep Boys, or Auto Zone carried.

The Mustang blew heater cores multiple times, the last one while I was flogging my favorite twisty road.

I was wound up around 4000 RPM when it popped...I heard it...then my feet were hot & wet.

Split at the seam on the end where the tubes are attached.

The one that came out of the T-Bird was swelled the same way.
I will try to post a photo when I get time.

I guess the question is should I use some sort of restrictor, or fabricate a bypass.
Has anyone done either?
The hitch is that here in the Northeast, I kinda need heat in the winter....

Too much restriction or bypass could make things chilly....

Thoughts? Comments?

You can still buy a heater core from Ford for about $52. Do you have aftermarket water pumps on the cars? If I was having that problem I think I'd rig up a water pressure gauge on the inlet to the heater core to see what is happening. Did the original Ford core split also? Had you changed the water pump before the core split?

I have two thunderbirds my 95 thunderbird LX with the 4.6 and my 91 thunderbird SC. I have had to replace the heater core in both of them. I got them both from ford and havn't had any problem since. My lx was fixed over 3 years ago and still good my Sc was fixed last year I also got my coolant from ford and flushed the system as good as can be done.

I recomend you try the motorcraft parts when it comes to the cooling systems on these cars hope this helps you out man.

And by the way everyone I'm back!

maybe a thermostat or headgasket? even new thermostats go bad