My sunfire and I are both in Chicago, hot summers/cold winters. It has 137k miles on it. Late last summer it suddenly began idling hard and overheating rapidly with the AC on; a sucking/hissing sound can be heard then too, like the car is gasping for air.
Almost no problems with the AC off, though it did just stall out on the first day of 80+ degree weather we’ve had this year. Without AC on, without overheating. That didn’t happen all winter.
Does anyone know what the most likely cause is? Any suggestions for how to determine a likely cause before taking it to a mechanic? I like this little car but of course, any substantial repairs will easily outstrip its total value at this point. Spending $1k or more in repairs feels a little silly.
So many things can be happening here and you did not say if the check engine light is on or not.
Given your description, I’d say the AC compressor is destroying itself internally. A new compressor, and the several items that must be replaced as well, will cost you $1800 or so.
This valve controls the engines idle speed depending on the load put on the engine under certain conditions so the engine doesn’t run rough or stall out.
So when you turn the AC on, the load of the compressor on the engine can cause the engine to run rough or stall out.
Sometimes the IAC valve can be removed and cleaned along with idle air bleed port on the throttle body with throttle body cleaner.
But I found most of the time they required replacement.
Thanks Tester. I’m fairly ignorant as a “car guy” but this somehow sounds likely. It’s ringing a bell, like maybe it’s something that a mechanic said would have to be done sooner or later.
Anyway thanks! If this DOES turn out to be the issue, looks like repair cost might not be prohibitively high. Fingers crossed.
You might try to narrow down where in the engine compartment the hissing sound is coming from by listening through a short length of old garden hose. No experience w/your particular car, but the symptoms are generally consistent with a significant vacuum system leak. These sorts of leaks are often located at one of these spots
