Guys,

I've been more of listener than a contributor on this forum, but now I hope I can help others with my experience.

Background:
1987 B2K Callaway Corvette, would overheat with A/C on and ambient temp was "warm" (not hot).
Even inclines would see the temperature spike.
Enthusiastic use of the gas pedal would also see the temp raise, but would also slowly come down...eventually.
So I wasnt enjoying it to the max.

Attempted fixes:
Cleaned out all the leaves, dead rats etc between radiator and condensor
Installed a higher pressure radiator cap
Reprogrammed the ECM to bring on the thermo fans 10 degrees lower temperature.

Result:
Still overheated.

On a recent drive home on the freeway, I took the time to take pics at various times during the drive.
The drive was approx 140 miles so plenty of time to observe what the temperatures were doing.

Started on the freeway at 50 mph (roadworks) - it held this temp pretty well

All looks good right?

Cleared the roadworks and moved up to 60mph - kept at this temp pretty well

Temperature creeping up, but nothing to much to worry about

Up to 70mph

Starting to warm up

Until it got to this

remember steady speed, open highway, 75 degrees outside.

Turned A/C off, helped a bit



At slower speed with A/C back on


Even at greatly reduced speed, with A/C on, it just couldn't cool down


The Highest it saw was 270!!

Next Post:
What I did next

 

Next:
I decided to remove the radiator and get it checked out

This is what I found when the local guy removed the end tanks

Keep in mind this is a factory heavy duty 3 core Radiator that is fitted when the B2K option is selected.

Of the 3x36 (108) tubes, only 40 were not COMPLETELY blocked.

Obvious now why it was overheating!!

The tubes were 3/8" from factory, the local guy made up a new core with 3 rows of 5/8" - so now super heavy duty.
You can see the difference in thickness here and how it completely fills up the tanks


Before anyone suggests I should have bought a Dewitts - I would have if I was in USA, but didn't want the car off the road for weeks

Next Steps:
Install radiator and install a 180degree thermostat.

Once its back on the road I'll report back

 

OMG I think you will be fine now. Good luck

 

Hi..

I haven't got the b*lls to run my Corvette at these high temperatures.

I have a new radiator, installed an adjustable thermostatic relay for the fan, a 160deg thermostat and a 21lb radiator cap that has a lever to let me burp it safely, and I run consistently between 175 and 185deg at either 80+mph on the motorway or in traffic in town.

One thing I learned quickly when I bought my '87, was that running full heat on the demister would drop the temperature by 20deg. Opening the windows to let the heat out works really well.

 

Good God you were plugged up. i think you will be fine now yeah. lol.

 

When I was driving it from Colorado to LA, over the rocky mountains, it was overheating and I did the following to try to keep the temps as low as possible without boiling the car.

As temps rose:
1. turn off A/C
2. slow to 60 mph
3. turn on heater with fan on high (open windows)
4 slow to 50 mph

Then depending on where the temps reduced to a reasonable level, I'd turn back on the A/C (as it was hot outside)

By carefully watching the temperatures, I managed to baby it all the way from Colorado Springs to LA, via the Grand Canyon.

The heater core obviously was acting as an additional radiator inside the car, but still took heat out of the engine.

Given the radiator only had approx. 1/3 working, the heater probably added enough to take it up to 2/3 cooling capacity.

Hopefully with the new radiator the problem will be solved

 

Good luck with the radiator!

I know it's off-topic, but I like the look of your gauge cluster bezel. Where'd you get that?

 

I just recently went through my cooling system. When I bought the car it had nice brown antifreeze (I haven't seen that in 25 years).
I flushed the block and radiator twice, put in a new 195* (stock thermostat), installed a new AC Delco radiator cap, and put a new water pump on. This was yesterday temp was only in the mid 50s outside at the time.

 

Installed the new super heavy duty radiator and took the vette for a 140 mile round trip.
Highest temp seen was 210.
The temp fluctuated between 185 and 195 most of the time.

I've installed a 180 degree, high flow thermostat as well.

Ambient temp was around 75 ish

It's almost running too cool now!!
Never happy are we? Lol

But bottom line, problem solved. Yay!!!

 

Congrats you are within specs!