Another heater core bites the dust.

[95oRANGEcRUSH]

This is such a pain in the ass problem to have. I JUST replaced my heater core about 11 months ago. The heater core went out again this past week. This will be the third heater core I've put in. I bought the car with 38,xxx miles and for all I know it was the original heater core. Put one in about 3 years later after purchase. Put the 3rd one in about 11 months ago. This time it's going to be bypassed and I'm not going to have heat in the car. F the heater core!

I think there is a major issue in the cooling system somewhere that is causing pressure to build and is blowing the heater core. That is my best guess. Most cars don't even require the heater core to be replaced and now I'm looking at #4. Bullshit.

:cuss:

 

[VirtualSVT]

Ya know SSP fox bodies had restrictors in the inlet hose to the heater core to help control pressure and flow.

I'd make one up if I were you. It was just a copper plug with a hole drilled in it on my fox body.

Oh and I've heard horrible things about parts store heater cores. I bought mine from Ford and never had an issue with it.

 

[lwrs10]

I just changed my heater core on my beater Fox, and there is a few things you MUST do to keep it from happining again....

First thing...ONLY BUY AN OE FORD HEATER CORE. The Autozone ones are crap.

Biggest thing is to have a restrictor on the intake hose of the heater core. You can get one from ford for $38, or you can buy a cheap 1/4 drive 1/2 socket. Fits like a glove. If you want the Ford part #, its E7VY-18D358-A

Next thing is you have to scrape all the old sealant out of the heater core box. Old sealant will cause it to sit uneven and eventually bust again. When you reseal it, use the thermal silicone like you would use in HVAC in houses. This will keep flex/bumps/rattles from stressing the heater core. It also has a very good thermal expansion rate similar to the heater core.

And instead of the 16# radiator cap that my car is supposed to have, I went with an 8#. With a 185 degree thermostat, I will never come close to needing a 16#. Less overall pressure on the heater core the better.


I have installed a few in my friends cars with this method, and NEVER had another bust on me. And I'm talking 100k miles on a 351 coupe that gets ragged on hard.....still leak free.....

 

[COBRASVT]

As stated above, don't ever buy used or anything other than Ford OEM.

What were the ones you've been replacing?

BTW...I've had to do mine twice...the 2nd time because the ass'hats that installed my engine broke my other one! :fm: :cuss:

Good luck....not having heat when it's cold sucks!

 

[95oRANGEcRUSH]

Lots of great advice here. I know the 2nd one was OE Ford. The 3rd one was an AutoZone special. I don't remember using a restrictor so I doubt that we put one in. I'm copying this advice for the next time we fix it. I'll get an OE Ford core and do everything that was mentioned here. Maybe it will actually stay operational for longer than a year.

 

[COBRA97SVT]

As stated above, don't ever buy used or anything other than Ford OEM.

What were the ones you've been replacing?

BTW...I've had to do mine twice...the 2nd time because the ass'hats that installed my engine broke my other one! :fm: :cuss:

Good luck....not having heat when it's cold sucks!

I broke mine on install as well. The copper line came out, i can feel the line fit back in place but nothing there to secure it. Could i take it some place and have them reglue it or whatever it is w/ copper. Or is it just broke?

 

[terminated94]

I have one out of my 94 cobra that I will sell cheap if interested.

 

[COBRA97SVT]

not sure if mine is fixable or not..

 

[COBRASVT]

I broke mine on install as well. The copper line came out, i can feel the line fit back in place but nothing there to secure it. Could i take it some place and have them reglue it or whatever it is w/ copper. Or is it just broke?

You could because it's just soldered in, but since you have to take it all apart anyway to get to it, I'd just replace with new. That way, the insides are new as well.

 

[Dragonhunt]

I just changed my heater core on my beater Fox, and there is a few things you MUST do to keep it from happining again....

First thing...ONLY BUY AN OE FORD HEATER CORE. The Autozone ones are crap.

Biggest thing is to have a restrictor on the intake hose of the heater core. You can get one from ford for $38, or you can buy a cheap 1/4 drive 1/2 socket. Fits like a glove. If you want the Ford part #, its E7VY-18D358-A

Next thing is you have to scrape all the old sealant out of the heater core box. Old sealant will cause it to sit uneven and eventually bust again. When you reseal it, use the thermal silicone like you would use in HVAC in houses. This will keep flex/bumps/rattles from stressing the heater core. It also has a very good thermal expansion rate similar to the heater core.

And instead of the 16# radiator cap that my car is supposed to have, I went with an 8#. With a 160 degree thermostat, I will never come close to needing a 16#. Less overall pressure on the heater core the better.


I have installed a few in my friends cars with this method, and NEVER had another bust on me. And I'm talking 100k miles on a 351 coupe that gets ragged on hard.....still leak free.....

Hey, Where can I get a tube of the "Thermal Silicone" at? How much will I need to do the job?

Thanks

 

[lwrs10]

Hey, Where can I get a tube of the "Thermal Silicone" at? How much will I need to do the job?

Thanks

I just used the stuff you can get at a hardware store. It says its duct sealant or something....