2011 Base - rough idle
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2011 Base - rough idle
I just picked up a 2011 1LT with 40k miles. At idle, the engine hunts +-50ish RPM, intermittently (but frequently). Occasionally there are more severe dips that threaten to stall the engine.
When it's happening, it sounds vaguely like a cam'd car. Off of idle, it runs great - no hesitation or anything else indicative of a problem that I've been able to detect.
Sometime in the car's past, someone installed an aftermarket intake & air filter. I haven't yet checked to see if this is an oiled filter (bad) or a dry filter.
The shop said that the idle was due to the filter. This strikes me as plausible but unlikely.
Any suggestions on where to start looking? Going to hook up HP Tuners later and look at fuel trims, etc.
When it's happening, it sounds vaguely like a cam'd car. Off of idle, it runs great - no hesitation or anything else indicative of a problem that I've been able to detect.
Sometime in the car's past, someone installed an aftermarket intake & air filter. I haven't yet checked to see if this is an oiled filter (bad) or a dry filter.
The shop said that the idle was due to the filter. This strikes me as plausible but unlikely.
Any suggestions on where to start looking? Going to hook up HP Tuners later and look at fuel trims, etc.
Last edited by David Lively; May 2, 2020 at 02:19 PM.
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Joined: Sep 2013
Posts: 15,597
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From: Cape Coral, Florida
If a vacuum leak fuel trims will be elevated...run the engine at 3000 RPM...if fuel trims decrease after a few minutes that signifies a vacuum leak !!
Last edited by C5 Diag; May 2, 2020 at 06:02 PM.
