Getting hot on freeway but stays cool at stop/low speed??

[CSCOBRA03]

I went through the same issue with getting hot 235 degrees on the highway in 100 degree day. The big issue with our cars is lack of airflow even at highway speeds. I did it all 170 degree thermostat, set cooling fan to turn on earlier, 180 degrees that all helped but did not fix the issue. The thing that fixed it was going back to the stack radiator, I also had a thick Fluidyne radiator and that is the key, it is to thick and doesn't get the sufficient air flow. Two things that would help, #1 duel fans with a proper shroud, or #2 open up the frontal area of the car or both. I solved my issue going back to the stock radiator and now it stays no higher than 190 ib 110 degree heat.

It's all about airflow into and out of the radiator, more air in and more hot air out. I didn't want to loose my a/c or cut the front body work or change my hood. I was blessed that the thinner stock Ford radiator took care of my heating problem. I hope this helps you.

 

[04OWwhipple]

I went through the same issue with getting hot 235 degrees on the highway in 100 degree day. The big issue with our cars is lack of airflow even at highway speeds. I did it all 170 degree thermostat, set cooling fan to turn on earlier, 180 degrees that all helped but did not fix the issue. The thing that fixed it was going back to the stack radiator, I also had a thick Fluidyne radiator and that is the key, it is to thick and doesn't get the sufficient air flow. Two things that would help, #1 duel fans with a proper shroud, or #2 open up the frontal area of the car or both. I solved my issue going back to the stock radiator and now it stays no higher than 190 ib 110 degree heat.

It's all about airflow into and out of the radiator, more air in and more hot air out. I didn't want to loose my a/c or cut the front body work or change my hood. I was blessed that the thinner stock Ford radiator took care of my heating problem. I hope this helps you.

That is very interesting. Where are you located at out of curiosity? That might be something I try at some point then as I'm kind of running out of ideas.

I just took the car for a test drive and it was 60 degrees outside and still crept up to 195 while driving which is still super high in my opinion for that kind of ambient temp.

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[CSCOBRA03]

I live in ST. George, Utah, it was over 100 degrees for 3 months, we are on the north edge of the Mojave desert.

Thought that I had a blown head gasket first but that checked out fine, I also did a vacuum fill and I did have a air pocket but it still would get hot. I did a ton of research and it's all about air flow, reinstalled my factory radiator and it's perfect now. Hope this helps.

 

[98 svt]

I live in ST. George, Utah, it was over 100 degrees for 3 months, we are on the north edge of the Mojave desert.

Thought that I had a blown head gasket first but that checked out fine, I also did a vacuum fill and I did have a air pocket but it still would get hot. I did a ton of research and it's all about air flow, reinstalled my factory radiator and it's perfect now. Hope this helps.

What radiator were you using before swapping back to the OEM?
I had to pull my OEM and swap in a Champion 3 row to take of my heat issues.

 

[CSCOBRA03]

I had a Fluidyne 3 row.

 

[04OWwhipple]

I have been thinking about the head gaskets as well. Not so much head gasket leaking but the size of the coolant passage through them. I used Fel pro high performance 1141L and 1141R gaskets when I reassembled the engine. These fit all 2V, 3V, and 4V engines. However they show separate different part numbers for each GT, Mach 1, and cobra trims for stock replacement gaskets. I called felpro and was informed the head gaskets on the 1141 gaskets have smaller passages than the stock cobra passages. I'm wondering if this is contributing as I didn't have this issue before the engine rebuild. I haven't heard of anyone else using the 1141s with this running hotter issue though when reading build threads on the forum.

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