2005 Chevy Uplander Has a Rough Idle – What Causes This?

Reader Question Hello Austin, I have a simple yet very irritating problem. I have a 05 chevy Uplander V6 travers mount front wheel drive. It currently has 48,900 and I have meticulous records and service. The engine has one problem in that it will not keep a steady idle.

The idle fluxuates from 500 to 800 RPM. It fluxuates at idle,in drive, with or without the air on. Had injectors serviced and it did not seem to help. No service codes either and no engine light. Help! It idled fine the first 26,000 mile the gradually got to this point.
Mike C.

Hi Mike

This vehicle is still under warranty for most people (unlike you driving 48K miles in a year)…..so we have not had any dealings with it in our shop except minor oil changes etc.

Any other vehicle I would first clean the throttle body and the idle speed control motor. These items get dirty with carbon deposits and will cause an erratic or rough idle like you mentioned.

Most dealerships have an “upper intake” cleaning service that will include cleaning these items.

Austin C. Davis

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