2008 Chevrolet Avalanche LTZ 8 Cyl 6.0L
what causes rough idle
milage 88000, mild case of semi rough idle(hardly noticible) just put a new set of plugs in
Dirty throttle plate-add cleaner available all parts stores. BG brand 44K very good, only available at shops. Could be fuel issue, very common this time of year, when winter/summer blends of fuel change. If not bad enough to cause misfire codes, don't worry about it . DO NOT throw parts at this problem, probably caused by fuel. If there is a problem that needs to be addressed, I assure you Check Engine light will illuminate. Until then, don't fret. The Engine control module will let you know if there is a problem you should be concerned about. Please reply to this post, as there is no gratification to visiting this site due to no feedback/dialogue, and I am looking for a reason to continue offering my not inconsiderable expertise to people for nothing.