Rough Idle 2008 5.3 Flex

[RAT-ON]

Guys, I have been searching on here and not really seen an issue exactly as mine and with a truck as new as mine. When in gear setting at a stop light (a/c on or off has no effect) my truck idles rough. You can't actually notice anything on the Tach, but you feel it in the truck. Pretty noticeable. I took it in while it was under warranty (around 30k) and they just said it needed a throttle body and injector cleaning for $$$$. I cleaned the throttle body myself since I have to do my wife's Envoy on an annual basis and ran some injector cleaner through it a few times and no change. I do not believe this is my issue and never did. I am not getting any codes, and have not driven another truck for comparison. Does anyone else's truck do this? Mine is the iron block, flex 5.3. thanks-Jason

[semper3318]

I have the same issue, and needless to say it is aggravating. My truck idles rough but of course won't throw any codes. I guess nowadays without a code GM just says nothing is wrong. From what I've seen online the problem is widespread but GM currently won't admit to any problems. If you find an answer please let me know. I have an appointment for dealer warranty coming up to try and get some answers. I'll let you know if I do.

 

Guys, I have been searching on here and not really seen an issue exactly as mine and with a truck as new as mine. When in gear setting at a stop light (a/c on or off has no effect) my truck idles rough. You can't actually notice anything on the Tach, but you feel it in the truck. Pretty noticeable. I took it in while it was under warranty (around 30k) and they just said it needed a throttle body and injector cleaning for $$. I cleaned the throttle body myself since I have to do my wife's Envoy on an annual basis and ran some injector cleaner through it a few times and no change. I do not believe this is my issue and never did. I am not getting any codes, and have not driven another truck for comparison. Does anyone else's truck do this? Mine is the iron block, flex 5.3. thanks-Jason

[redjewel2ss]

when you cleaned the throttle body, did you look inside the intake manifold for any oil build up? it's possible there is some in there which is "normal" because the stock PCV system allows for some oil blow by. a can of Seafoam intake spray will clean that stuff up real good!

 

it's also possible your injectors are clogged with junk that standard injector cleaner through the fuel system is not cleaning up. i would recommend finding a shop that services cars using BG products. best stuff hands down to clean your fuel system and upper cylinders up! what they do is hook up a line directly to the fuel rail at the service port and pump the cleaner in right there at the source, so it isn't diluted down by your fuel in the tank.

http://www.bgfindashop.com/locator/index.php

 

if this fixes your problem, start filling up at stations who carry only top tier fuel! that means no more filling up at wally world or your local grocery store

http://www.toptiergas.com/retailers.html