Ok I've read a few post regarding this issue. I have taken my Tahoe in too many times to count. Motor mounts have been changed last year but still shakes at idle. Anyone else have anything else changed/fixed and issue go away? Bumper to bumper ends soon so want to get it taken care of before i just sell the thing back to chevy and buy something else!!!

 

Hard to say will the limited info provided.

What all has been done in an attempt to repair this? What do they think it is?
Is the check engine light on?

 

In my opinion if what you post is accurate, park the vehicle at the dealer, and NOT accept it till it is fixed

 

What Kevinkpk said. Have you tried getting the OBD codes from
a scan tool independently? It sounds like some job the dealer's trying
to blow you off. Insist they fix it.

 

 

Subject: I fixed my rough idle problem
Hi everyone,
I am posting here my issue and how I fixed it in case somebody may benefit since the rough idle seems to be pretty common. I bought a new 2018 Tahoe like 60 days ago. It was fine when I got it until the odometer reached around 700 miles when I notice the idle had become very rough for moments while in drive at a red light. The problem has been more noticeable once the engine is warm. It was shaking and acting as if misfiring but no check engine light was on. The local dealer told me this was normal but did not inspect it. GM customer support told me to wait further until the engine reaches more miles (however, the manual only alludes to 500 miles as the breaking in period). I am not a mechanic but a doctor. Nevertheless, my perception of this sudden "normal behavior" of the engine did not seem to me like normal. This is what I did: I inspected the MAF sensor and it the bolts seemed to be not well torqued so I re-torqued them. The bolt on the clamp that holds the air intake to the air filter housing seemed also somehow loose so I re-torqued it. The same was notice on the clamp that holds the intake to the throttle body and I did the same there. Guess what, it now works as the day I bought it. I don't know the rationale for my findings but I suspect that my humble adjustments corrected a small vacuum leak. The idle is not like butter when compared to other cars I have owned but it is now good enough as I recalled it to be at the beginning. I will update my post within 30 days or earlier if the roughness returns. As an observation, I inspected the opening at the TB and it was super clean so deposits was not the cause, I think. Good luck.

 

Good catch,what happened was your vehicle was a donor for another problem truck,parts swapping,not a big deal,but someone was in a hurry

 

 

I bought a 2018 Tahoe new 2 months ago and have had a rough idle from the beginning. No codes and dealer says its normal. I have checked the air intake hoses and MAF sensor torx screws. The roughness seems to be getting worse when at a stop light in drive. I am irritated after spending al this money on a vehicles and it idles rough. Its really annoying.. Any clue on where I can look/do next.. Any help would be much appreciated.

 

My 2016 Tahoe had a similar sounding rough idle w/o any codes or computer issues. Ended up being the body mounts being torqued incorrectly at the factory, according to the service bulletin the service adviser showed me on their screen, it is a known issue covered under the 60K warranty. They replaced all of the body mounts, torqued them the right way, and now it idles super smooth.