Overheating
Thread Starter
2nd Gear
Joined: Sep 2016
Posts: 2
Likes: 0
Overheating
I just recently bought a 1981 Corvette. when the car is operating at low RPM the water temperature never warms up the air conditioner works and the alternator works. When driving at 65 70 miles an hour the car heats up almost to the point of overheating the alternator stops working the air conditioner stops working. I have replaced the thermostat and flush the radiator and the belts all seem to be tight. Any ideas on where to start to look for this problem thank you
Thread Starter
2nd Gear
Joined: Sep 2016
Posts: 2
Likes: 0
At 70 mph it is 240-250. I slow down to 60 the temp is around 230. I slow down to 30 mph the car cools down and it runs about 150 degrees.
shouldn't the car warm up and run about 200 degrees uuless driving 70 with the ac on? My alternator reads below 12 volts and the battery light comes on at 60 to 70 mph. My ac also stops blowing cold air at those speeds.
shouldn't the car warm up and run about 200 degrees uuless driving 70 with the ac on? My alternator reads below 12 volts and the battery light comes on at 60 to 70 mph. My ac also stops blowing cold air at those speeds.
Drifting
Joined: Aug 2009
Posts: 1,346
Likes: 160
From: new iberia la
check for obstruction in front of condenser and radiator as well as in between them ..trash bags, leaves, dirt, mud birds etc.. sounds like airflow is restricted at speed ..A/C will not blow cold if condensor isn t cooled .Do you have the extension on front spoiler?. also check your fan clutch . If you continue at 250*, you will lose a head gasket
Burning Brakes
Joined: Dec 2005
Posts: 1,164
Likes: 224
From: Pawleys Island, SC
I don't believe it should ever run at 150 degrees, 30 MPH or any speed. Sounds like maybe an issue with the gauge or temp sensor.
A lot of the time it seems that high temps are the result of not having the required seals around the radiator allowing air to bypass it.
A lot of the time it seems that high temps are the result of not having the required seals around the radiator allowing air to bypass it.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,209
Likes: 9,347
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Pics of engine compartment, front of engine, radiator, front of radiator and underneath the front of the nose will help
Drifting
Joined: Apr 2011
Posts: 1,689
Likes: 174
From: Deerfield Illinois
2022 C3 of the Year Finalist - Modified
C3 of Year Finalist (appearance mods) 2019
There is a article in the tech section of Corvette Fever where a guy had the same issues as you. He had a crap load of leaves and debris between the AC Condensor and Radiator. Looked like a blanket. They pulled them out of the car and showed a picture of it. I'm sure you can find it via Google.
Also check coolant to water ratio.
Also check coolant to water ratio.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,209
Likes: 9,347
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
You can go to a radiator shop and get it flow tested
Last edited by Rescue Rogers; Sep 28, 2016 at 07:27 PM.