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post #1 of 13 (permalink) Old 07-21-2013, 04:42 PM Thread Starter
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Fluctuating RPM at Idle

Hello all,

2006 Cobalt LS

Noticed when I turn on the A/C that the RPM's start to fluctuate,almost stalling.
When I turn it back off it idles better.
any ideas?
thank you,
Tony F.
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post #2 of 13 (permalink) Old 07-21-2013, 05:05 PM
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Dirty throttle body....

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post #3 of 13 (permalink) Old 07-21-2013, 05:33 PM
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Coby, could that also cause a very light vibrating when stopped in drive? I don't feel it when I put it in neutral. Or is that just the motor pushing against the brakes?

2005 cobalt base model coupe
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post #4 of 13 (permalink) Old 07-21-2013, 05:35 PM
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Quote:
Originally Posted by swanman35 View Post
Coby, could that also cause a very light vibrating when stopped in drive? I don't feel it when I put it in neutral. Or is that just the motor pushing against the brakes?

2005 cobalt base model coupe
Maybe transmission or motor mounts are getting a bit mashed.

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post #5 of 13 (permalink) Old 07-21-2013, 05:37 PM
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That won't cause damage to any other parts would it?

2005 cobalt base model coupe
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post #6 of 13 (permalink) Old 07-21-2013, 07:44 PM Thread Starter
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uhh meanwhile back at the farm...

okay I had someone turn the key on and push the pedal to the floor so I could clean the throttle body which was dirty but now it idles to high, now what to do?
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post #7 of 13 (permalink) Old 07-21-2013, 09:58 PM
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Is it a cold engine? wait a few minutes until it can pick up some heat, the idle should come down to below 1000rpm.

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post #8 of 13 (permalink) Old 07-21-2013, 10:07 PM Thread Starter
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Quote:
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Is it a cold engine? wait a few minutes until it can pick up some heat, the idle should come down to below 1000rpm.
Thanks PJ,

no the engine is warmed up and driven several miles and still idles too high about 1500 RPM.

should I disconnect the battery to reset the ECM?
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post #9 of 13 (permalink) Old 07-21-2013, 10:47 PM
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You didn't read the "how to clean throttle body" did you? Key must not be in ignition while cleaning throttle body. Now you will have to do a relearn.

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post #10 of 13 (permalink) Old 07-22-2013, 04:10 AM
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Yep, to the dealership!

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