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Overheating

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Old Sep 27, 2016 | 12:06 PM
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Default 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
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Old Sep 27, 2016 | 12:14 PM
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200-220 is normal operating range. What reading are you getting at high way speed?
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Old Sep 27, 2016 | 02:38 PM
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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.
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Old Sep 27, 2016 | 06:03 PM
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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
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Old Sep 27, 2016 | 06:32 PM
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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.
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Old Sep 27, 2016 | 06:59 PM
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how about the belts and fan clutch?
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Old Sep 28, 2016 | 08:17 AM
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Pics of engine compartment, front of engine, radiator, front of radiator and underneath the front of the nose will help
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Old Sep 28, 2016 | 02:24 PM
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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.
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Old Sep 28, 2016 | 07:26 PM
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You can go to a radiator shop and get it flow tested

Last edited by Rescue Rogers; Sep 28, 2016 at 07:27 PM.
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