STS on 05 350. Engine runs hot when A/C is on in stop and go traffic. Did any of you F/I guys upgrade your radiator? What make can you suggest? KOYO, Stillen,etc. I was checking out the KOYO V2577 or R2577. R is about 20 mm thicker than the V(36mm). Do you know if I would have clearance issues with the R?

 

Can't go wrong with a V core koyo...Mishimoto also makes a 36mm core radiator for a little less...heard nothing bad about it...

 

probably just need to bleed the system to remove air

 

I went with the Koyo R and had to have some modifying of the fan shroud to make it fit. IIRC the smaller Koyo is the same size as the OEM

 

+1 try this first before you upgrade.

 

+2

 

1. Check thermostat.
2. Cooling system flush.
Go from the easiest/cheapest possibility, & work yourself up to more expen- sive/more difficult stuff. Visiting an A.C. Service/Maintenance Shop should aid
determine the culprit.

 

The V core Koyo or the Mishimoto are 36mm and will fit without any additional work. They are still about 3 times as thick as the stock piece of garbage, which I would not even run on an FI Pinto.

However, if you are overheating in stop and go traffic, your issue is probably just air in the system.

 

What kind of cooling temps are you seeing? Plus it is hotter than hell down here in Florida

 

Thanks for the input. I"ll check out the bleeding issue first. I only have the stock temp. gauge on the car, so I dont have a true number on how hot engine gets. Stock guage reads just under the hot setting and goes to full hot if I dont turn A/C off at stoplight. Running down the road at boost, engine at normal temp. I'll probably go with the V Koyo just for insurance.

 

I was mistaken, the V Koyo is twice the size of stock rad

 

I'm running Greddy TT's w/ only the stock radiator. I've had no problems with over heating. I'd def try bleeding the system first.

 

Bumping this for a small trick I learned today.

Due to my slow coolant drip out the rear crossover pipe, I have been getting air into the system. I had just been keeping the radiator topped off. Well after doing a track day two weekends ago I guess I lost enough coolant to cause a big air pocket, and the car started overheating two days ago. I parked it and left it there.

I go back today to bleed it out so I can bring the car home, and after struggling to get it to bleed the air out for a half hour, I started to "massage" (squeeze and release) the upper radiator hose - almost instantly big air bubbles started coming up into the spill free funnel. I did this with the engine running. System was completely bled in only a few minutes, temp gauge read normal again and the heater was blowing HOT air.

Just something else to try if you're having a hard time bleeding the system.

 

There is also a cooling system air bleed here:

 

Unfortunately for those of us with the APS TT's that handy little bleeder valve is no longer there....I have read so many different ways of bleeding the air and was wondering.. if the heater is blowing hot air, does that mean all the air is out of the system????

 

Here is my guess....I bet only one of your fans are working The reason I am saying only one is working is because you said that it over heats only with the AC on...but still gets a little hot with the AC off. I had the same problem. One fan is not enough to keep it cool with AC on...but one fan can keep you going with it off.

Just check to see if both are working.....Keep us updated.

 

Well aware, that is the bleed valve I've always used. However, I today I found it exceedingly slow compared to sqeezing the upper radiator hose repeatedly, revving the engine repeatedly, and repeating.

Of course with this method a spill free funnel is a must.

 

Massaging the hose always works.....