87bob

Just got back from Vettes on the Rockies. Man it was Hotttttt!!!!!!!!!!! Crossing the east slope of the Rockies and Kansas. Temp gauge on the wife's 79 got up to 250+ she didn't boil over but had to be close. Which brings me to my question for the Forum Members. The car runs 220 or below on the gauge if I keep it under 60/65 without the air. It has the shroud intact, has a new clutch fan, stock water pump all seem to function ok. Why does it heat up when running the air or jumping the speed? I am guessing that I am not getting the air or water flow I need but I dont know where to look or where to start. She wants to be able to run the air next trip or else!!!!!! Could mean trouble when Mama's hot she's not happy. Thanks in advance to anyone that can offer me a solution. :confused: :confused: :confused: :confused:

Thanks one and all for the tips!!!! I'll check them out and post results.


[Modified by 87bob, 4:37 AM 8/13/2003]

gdh

what thermostat are you running, have you added Water Wetter, is the foam surround intact to force the air through your rad instead of allowing it to go over or around it, is your evaporatorclean or clogged up.

78Vette-SA

In addition, when was the last time you had the radiator flushed and pressure tested?

Smokehouse69

:iagree:

If the car is mechanically in good shape and the tuning is up to specs (timing) then the radiator has to be the limiting factor. If it is an original radiator there's a good chance that it is badly fouled with rust and hardwater minerals.

87bob

Foam what foam I got no stinking foam? :lolg: Yes that is tomarrows project. Does anyone know where to get precut kits of the foam. The NAPA guy says they have it 25 foot rolls but I haven't seen it yet. Can you tell me where it goes?

Smokehouse69

Corvette Mall Link
http://store.yahoo.com/zipproducts/c...ort-seals.html

The illustration is for a 69, but the other year models are similar. Another thing to look at is your chin spoiler if it is missing it can really have a negative effect on the air flow into your radiator.
http://store.yahoo.com/zipproducts/b...-spoilers.html
As a final thing to look at is if you have a front license plate and your state doesn't require one, remove it.

Tom454

"If the car is mechanically in good shape and the tuning is up to specs (timing) then the radiator has to be the limiting factor. If it is an original radiator there's a good chance that it is badly fouled with rust and hardwater minerals. "

Ditto

I do radiator repairs and you would not believe the crud that accumulates inside the radiator at the tube ends... crusty!

If the car has ever received a dose of "Stop Leak" or "Bars" etc then the chances are the tubes are at least partially plugged. I unsolder the end tanks to clean these and to "rod" the tubes.

But to reiterate:

"If the car is mechanically in good shape and the tuning is up to specs (timing) "

Lately, I've been getting lazy and just replace the radiator if it's plugged,

Wrencher

I did a little experiment on mine relating to this. Mine heats a bit with the A/C on, when the temps get up above 90 or so. I have all the factory foam seals, stock fan w/clutch, etc. I got out a roll of duct tape and taped off EVERY crack, seam, joint anywhere near the radiator so that absolutely all the air went through it. Didn't solve the problem entirely, but made a big difference! I'm going to upgrade to an aluminum radiator with dual fans to solve this problem once and for all. (yes, I took the tape back off! I am not bubba... yet.)

One thing that hasn't been mentioned here that is very important on our marginal systems is the chin spoiler. Even as small as many of the stock ones are, they are vital in hot climates. I run a custom 3" model that helped a bunch, and it looks good. Made it out of 3/16 black conveyor belt material, so it doesn't break every time I bump a curb or other such silliness.

Hans

UKPaul

All good advice above. My '81 (with improved airflow through the rad compared to '79 & earlier) was running at around 180/190 with a 180 stat, re-cored rad, new hoses & no aircon. On fitting a 2004r it ran at about the same temp, but the tranny was running hot. So I fitted a tranny cooler between the tranny outlet & the radiator. The tranny runs cooler, but so does the engine coolant. It now sticks bang on the little mark on the gauge between the 100 & 200 temps (which I've been told isn't 150F, but 180F - I hope!!!). With ambient temps above 100F on Sunday (we've broken all previous records for temps :hurray: ) I couldn't get the coolant temp up to 200F, no matter how hard I tried ;) I don't have the seals around the rad but I also don't have the aircon condenser blocking the airflow to it. If all else fails then a cheap tranny cooler might just help you out.
The point on the rad weld was a good one. My rad, stat & hoses had loads of crud in them from the stuff. It had stopped the rad leaks but the temp frequently climbed to over 200F on hot days & heavy throttle.
:cheers:

NHvette

Not sure on your year - but my 75 has a shroud 'extension' around the trailing
edge of the shroud. Mine was missing. I fabbed up a new piece and the temp
problems went away. Without the extension, the fan sits behind the shroud
edge and can pull air in from the side, instead of through the radiator.

:seeya

72GACRZR

If you missed it, this is a good review of the entire system.
http://www.dewitts.com/download/Corvette%20cooling.pdf

Hope it helps. :seeya