Engine rough

Discussion in 'Engine & Drivetrain' started by rjr, Aug 7, 2018.

  1. Doubeleive

    Doubeleive Elite Member Supporting Member

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    Wes
    and the dealer should be able to adjust it upon request as well, I don't know why they would say it's unrepairable that sounds like a total copout
     
  2. rjr

    rjr TYF Newbie

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    Doubelieve, I have been advised, and it has been repeated in this forum, that trying to move the throttle plate by hand in a drive-by-wire system will damage the motor. This is a 2015.
     
  3. Doubeleive

    Doubeleive Elite Member Supporting Member

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    I suppose it could happen if you bent it or was rough with beyond the norm, I have done mine multiple multiple times on 3 different vehicles (all drive by wire) and never had a problem as many others have. let me ask you this, what the heck do you think the mechanic does when he does it and gets paid handsomely for it????
     
  4. dmad1

    dmad1 Member

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    Our '12 started idling rough and it was the injectors. Ran two tanks of Techron with no change, ran two tanks of Sea Foam with no change. Then ran two tanks of Amsoil P.I. (Performance Enhancer) and it not only smoothed out but the mileage improved. Made a believer out of me for Amsoil P.I. It's about $10 a bottle.
     
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  5. jcgvt01

    jcgvt01 TYF Newbie

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    May be ground out through engine mounts. I'm experiencing these same symptoms myself at 34,000 on a 2016 LT

    Found a GM Tech service Bulletin.

    Bulletin No.: PIP5211E


    Date: Jun-2016


    Subject: Rough Idle In Drive


    Models: 2015-2016 Cadillac Escalade Models

    2014 Chevrolet Silverado 1500

    2015-2016 Chevrolet Silverado 1500, Suburban, Tahoe

    2014 GMC Sierra 1500

    2015-2016 GMC Sierra 1500, Yukon Models

    With engines 4.3L, 5.3L, 6.2L RPO L83, L86, LV1, LV3


    Condition/Concern

    Some customers may comment about a rough idle and/or vibration at idle in Drive.

    This condition may be most noticeable following extended driving, after hard acceleration, while idling at a stop in Drive.

    May feel like a lopey or lumpy idle, or may be described as a low idle.

    This condition will not be present in Park, or Neutral.

    (There have been a few cases for rough idle in Reverse.)

    Note: There will not be any DTCs with this concern.


    Recommendation/Instructions

    This concern may be caused by ground out within the one or both engine mounts.

    Familiarize yourself with the entire PI before proceeding.

    If the rough idle / vibration concern is E1.5 in the horizontal / lateral direction with Pico sensor mounted in seat track as indicated – continue with steps to reduce

    the amplitude (mg) of the vibration by adding spacers in key locations to reduce / eliminate ground out within the engine mounts.

    Note: The 6.2L engine has a characteristic E1 which can be felt, and may be described as a lopey idle. V8 engine firing frequency produces E4 which will

    typically be very low frequency at the seat track. Do not confuse 6.2L E1 characteristic (not caused by mount ground-out), with E1.5 normal idle characteristics

    being transmitted into the truck via ground-out thru the engine mounts.
     
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  6. DLAv8r

    DLAv8r Member

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    I have the same issue on my 2017 since new (14,000 miles on it). I’m at the dealer right now getting an oil change and brought the issue up. They see it on the sierras as well and there is nothing GM will do to fix it.

    I’ve noticed it’s less severe for me when I run premium 93 gas. I need to check out the AMSOIL and report back. It sounds promising. The factory tune appears too low. I also get a little bit of surging when the Yukon is cold and I’m light throttle driving in my neighborhood. Very annoying for a 65k vehicle.
     

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