Ok so on my 88 IROC 350 car, I just put a new Victory 3 core rad in, had the 4th gen fans for awhile (they work great), new 160* tstat, and upper & lower hoses replaced w/in the last 10 months or so... Air dam is intact (one very small slit in the middle but it doesnt effect operation.

When I idol, w/ or w/o AC on, it stays in the 160-170 range. When I get much about 30 mph, the temp starts rising and wont cool back down until I come to a stop for a second. The only thing I can think of is that I'm missing some other under carriage plastics or that the pump is going out BUT can see the coolant PUMPING hard thru the rad. (The temp max's out around 220 or so but it should NOT be getting that high with the system that I have...)

This has be pretty stumped so opinions are welcome please...

Thanks,
Doc

 

That would be my guess as it cools no load/stationary w/fans.

 

Yea but why? I'm going to replace the h2o pump & put a 180* tstat in & see if that helps... Kinda at my end right now lol...

 

It sure sounds like an air flow problem to me. I don't think a new tstat or water pump is going to make any difference. What plastics are you missing underneath?

 

Wire your fans on constantly. If the problem mitigates, it's an airflow issue.

 

I have an air dam & nothing else as far as plastics go.

The fans are on a keyed switch already.

It has to be an air flow problem but I cant figure out what's causing the problem lol

 

Why don't you reinstall the plastics and see if that helps. They are there for a reason. I'm not saying the reason is airflow to the radiator, but I would be surprised looking at the shape of the lower nose underside piece.

Do you have anything blocking the radiator from getting air from the fog light holes?

 

The plastics weren't on the car when I bought it & I don't have any to put back on it. Nothing blocking the fog light holes either. I have a grill insert but that's it.

 

After looking at some pics of the plastics for the undercarriage, the only ones I am missing are the L&R pieces that extend from the air dam.