Overheating issues

[Devin LeBlanc]

Well im having a bit of trouble figuring out why I am overheating. I can drive around the city no problem, AC on and everything.. But when I get on the freeway weather the AC is on or off after about 3 min the temp starts climbing and gets into the red. I have been trying to find out why for a week now and trouble shooting and I am leaning towards the radiator. Im sure its not a blown head gasket, No smoke, No milky coolant, Water level and oil level stays the same. Head gasket was replaced 3000-4000 miles ago with a felpro and ARP's torqued to 90ft lb's, Head was machined as well. I have replaced the water pump, Thermostat, back flushed the block and have good flow through it. I am using a Tarus Electric fan on high speed which is sufficient for the application. Anyways, what do you guys think? Thanks in advance.

Thanks,
Devin

 

[CajunKenny]

It sounds like your rad can't hang with the additional heat from the transmission.

 

[Devin LeBlanc]

Thats what Im thinking, I might get an external trans cooler, But I ordered a new radiator from rock auto. Don't know when it will be here but hopefully it will solve the problem.

Thanks for the response!

 

[CajunKenny]

You're welcome. I hope that takes care of it.

Another way to confirm that your rad is the problem is, once the car is at op temp, get a laser thermometer and look for hot spots. Another possibility is that your transmission is overheating...

Just out of curiosity, is the rad coming from Rock Auto equipped with plastic or metal end tanks?

 

[Devin LeBlanc]

Im pretty sure its metal end tanks, I will try to get a infared temp gun and check

 

[Devin LeBlanc]

Well just a small update, Got the radiator. The one I ordered said copper core and brass end tanks, however I got an Aluminum core and plastic end tanks. Aluminum dissipates heat better anyways! Got it all installed, and wow what a difference. Temp stays alot lower. I drove round trip to cali state line from vegas with the AC blasting and 105-110F out. It stayed below half the whole time and even went down once I got back on the freeway! Looking closer into the fill hole of the old one the passages that I can see are completly plugged with gunk! Found my problem! Thanks for the responces!

 

[jetjock]

Not to be picky Devin but the thermal conductivity of copper far exceeds aluminum. The second is commonly used only because it's cheaper, lighter, and easier to work with. As for heat dissipation it depends on several things but all else being equal surface area is what matters.