AC Causing Engine Heat
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Joined: Mar 1999
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From: Fair Oaks CA
AC Causing Engine Heat
Driving around in my 89 coupe the other day, with an outside air temp of 90*, I turned the AC on and saw my coolant temp climb past 235* with no sign of slowing. I recently had an overheat of 262*, so I was paying special attention to my coolant temps.
Earlier that morning, I had removed the radiator shroud and cleaned out the debris, about a 2-inch layer of dead leaves. Driving around with the AC off, the coolant never got above 216*. With the AC on, it got to 235* before I shut it off. Immediately, the temp dropped and settled around 216*.
I know the coolant temp will increase with the AC on, but once it hits 230* or so, the big fan kicks in and the temp should drop, plus the aux fan that kicks on with the AC. Seems like there's something wrong with my AC system. Any thoughts?
-WL
Earlier that morning, I had removed the radiator shroud and cleaned out the debris, about a 2-inch layer of dead leaves. Driving around with the AC off, the coolant never got above 216*. With the AC on, it got to 235* before I shut it off. Immediately, the temp dropped and settled around 216*.
I know the coolant temp will increase with the AC on, but once it hits 230* or so, the big fan kicks in and the temp should drop, plus the aux fan that kicks on with the AC. Seems like there's something wrong with my AC system. Any thoughts?
-WL
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Joined: Jun 1999
Posts: 14,924
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From: Merritt Ils Fl
Re: AC Causing Engine Heat (White Lightning)
You are correct that the AC will increase temps. However I suggest you run a complete check of your cooling system before taking on the AC. From your description I will venture a guess that you have failure in some component. Could be a sensor,relay,fan or could be your ECM. Your manual tells you how to check each component.
