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2001 Saturn Mystery

Does anyone know what could cause a 2001 Saturn SL (manual transmission) to run near 2000 rpms during idle and when in low gear? The problem is intermittent but when it does it tends to persist until I shut down the engine. The car also has to be driven for at least 5 miles for this to begin happening. Other than that the car performs well, although my fuel economy may have declined by a small amount. I have been scratching my head over this for some time. Any info. would be greatly appreciated.



Thanks

The possibilities include a bad coolant temperature sensor, a bad IAC motor, and a bad MAF sensor. My money would be on the coolant temp sensor as the most likely problem, so I would suggest that you first eliminate that possibility before moving on to the other possibilities.

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For an intermittent fast idle, I look for an extra air input. These can come from several places. One possible place is from a stuck idle air control valve (iac).
When the fast idle occurs, tap on the iac valve. If no result, disconnect its electrical connector. If that’s not the cause, it could be a stuck open purge control valve, or a stuck open egr valve.
Here’s a picture of the idle air control valve. That big black intake tube, on top of the engine, goes to the throttle body and the attached iac valve.