Rough Idle when stopped.

TREY TURNER

MEMBER
BUICK LESABRE

I have a 1998 Buick LeSabre Custom with 40k miles. The car starts fine and runs fine but when stopped the rpms fluctuate from up to 1500 then suddenly drop to almost 500. At ths point, it acts as if it is going to die but hasn't yet. This idle cycling up and down has the exhaust missing and spitting but without smoke of any color. A non-professional scan was run that indicated an ignition concern. What do you think?

1 Reply

JDL

MECHANIC
16,098 POSTS

Sorry for the late reply.

How long since a tune-up? If you have applicable trouble codes, it's best to post them with your question. The basics for a rough idle is to check for a leak of some kind, fuel--egr--vacuum leak, something like that.

Also, clean the throttle body and idle air system, see if it helps. Check the maf sensor where applicable.

I realize this is an old post. In the future, hope you don't have any vehicle issues, but, if you do, keep the site in mind. They are always working to improve the site and it's free to ask a question. They have more moderators now, to answer questions, than they did several years ago.

Have a good day.