Hey guys
I have a bit of a problem I would like some advice on.
I had a major overheating problem in my vette.
I replaced EVERYTHING including...
Radiator, hoses, t-stat (180 degree), coolant, and had the waterpump tested and passed.
Turned out the major problem was from some idiot putting the t-stat in upside down (guy I bought the car from)
Anyway , I ran it all summer with it running about 210-220
About a week ago I took it out on the highway.
It was about 70 degrees and I ran about 105 mph for about a half hour
The car ran a little hot but not too bad (about 225-230)
Last night It was about 55 degrees out and I ran it about 70 mph for about 45 minutes and it got all the way up to around 260 !!
At that point I dropped it down to 55 mph and it started cooling down.
But even on an everyday basis in town doing about 40 it runs about 220.
What is going on ?
Any ideas how to fix this ?
I think it's time for an engine rebuild...
Thanks again guys


[Modified by Anar76, 7:27 PM 9/6/2001]

 

Anar76,

What is the condition of the front spoiler? Very critical for good airflow. Also make sure all the seals are in place around the radiator so all the sir flows through it and not around.
Or do what I did. Go full bore with BeCool radiator and Spal fans. Never broke 200 this summer cruising 70mph+ for 8 hours a day in 100+ temp cross country.

Totally different note. Did you make the Knigston show. Don't remeber your car there but I didn't stay long. (Mine is no condition for a show and shine these days.) Anyway, send me an email if you want to come down and check out my setup.

 

I had a similiar problem turned out to be my carb was jetted too lean. I had Lars rebuild and rejet it. I had it out on the highway Monday for 45 minutes @70 mph-2800 rpm and it stayed right on 180. It was about 80 degrees out.
Gary

 

Yea the front spoiler is gone. and by that i mean missing.
It's on my list for replacing but i'd want to get one of those indy style types.
and at about $300 it's gonna hafta wait a bit.

As for the carb running a little lean...That's very probable.
Don't know why I didnt think of that..
Thanks
I'll check it out

 

You NEED a front spoiler. If you want to wait for the indy style, go ahead and spend $40 or so for the OE style until then.

 

The front spoiler is probably the problem. Till you replace that, I doubt that adjusting the carb is going to make much difference. I didn't realize how much the spoiler did until I was under the car, taking mine off for the radiator swap. If you look at where it goes, you'll get a feel for how much air it directs thru the radiator.

 

You have pretty much answered your own problem. At higher speeds your car heats up, because high speed depends on air flow through the radiator, not air flow from the fan. When you slow down, the function of the fan is to blow air through the radiator. Get an air damn down below and make sure you have your radiator sealed well and you will be cruising high speeds at 180 degrees also.

 

First, and foremost, confirm that it is overheating. A common problem with these cars is that, over the years, temperature sending units get replaced and the overheating problems start. The replacement temp sending units are not calibrated the same way that the originals are. Find someone, like a radiator shop, that has a infrared thermal device and have them read your cars normal operating temperatures. If you can't do that, I have had good luck using my wife's candy thermometer which seems to be fairly accurate. If your hoses are not gurgling or antifreeze isn't spilling occasionally I would suspect your temperatures are not as high as they seem.

If your temperatures are up there then you have to start looking at the sources. Obviously, they put the chin spoiler there for a good reason. Get one! Secondly, you said that you had a new radiator. Is it of a sufficient capacity to cool your car? Is it a reproduction unit or a rebuilt unit that was designed for your car? Or is it a radiator out of McParts R Us?

Finally, do your parents know you were going 105 mph? :D

Gary