Overheating engine at idle

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Oct 13, 2019 | 11:59 AM

marty1003

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Joined: Jul 2019

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From: Georgia, USA

Overheating engine at idle

Issue: When driving at normal speeds the temp is normal and AC blows cold air. When I stop at a light or sit idle, the engine temp goes up and the air goes warm. I notice that "something" feels like it is kicking off when the air goes warm? I swapped out the thermostat and that did not help.

Oct 13, 2019 | 12:03 PM

Oh Boy

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From: Lower New York

Quote:

Originally Posted by marty1003

Issue: When driving at normal speeds the temp is normal and AC blows cold air. When I stop at a light or sit idle, the engine temp goes up and the air goes warm. I notice that "something" feels like it is kicking off when the air goes warm? I swapped out the thermostat and that did not help.

That would be the ac compressor, hence the warm air. What are your rpm's at idle? I believe too low could potentially cause your conditions. Could also be low on freon where there is not enough pressure at idle to keep the pressure switch activated. Are your fans running when you have the ac on? If the fan does not run, the condensor will not cool the freon back down. However, at speed, the air across the condesnsor will work that same as the fan. My guess is your fan is not coming on causing your ac to shut down and the car to run hot at idle.

Last edited by Oh Boy; Oct 13, 2019 at 12:12 PM.

Oct 13, 2019 | 12:18 PM

marty1003

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Joined: Jul 2019

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From: Georgia, USA

Thank you, the guy at Autozone suggested the same thing. I'll have to take it in for that.

Oct 13, 2019 | 12:27 PM

Dave S

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From: Jackson NJ

Quote:

Originally Posted by marty1003

Thank you, the guy at Autozone suggested the same thing. I'll have to take it in for that.

You might save yourself a shop repair bill by first checking the connections to the fans. Pull apart the connectors & check for either loose or oxidation on the pins. Clean the pins & use a bit of dielectric grease when you reconnect. That may be a simple DIY fix.

Oct 13, 2019 | 03:33 PM

FAUEE

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From: Melbourne, FL

Engine temp goes up at a light? Oil, coolant, or both? Your car should idle indefinitely without seeing a big spike in engine temps.

When you idle it, what temperatures do you see on the digital readout, and do your fans kick on? When was the coolant last changed? I'm wondering if you have a more serious problem with the cars cooling system than you realize, a failing thermostat, water pump, blocked radiator, etc.

Oct 13, 2019 | 04:01 PM

R&L's C6

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Do the easy things first, check and make sure your radiator isn't blocked by anything. I have read posts where a plastic bag had gotten sucked up and stuck to the radiator blocking air flow.