2018 5.3 Yukon idle flutter at the stop in Drive

[dvzzz]

My first post and my first GM truck. Came to American trucks from the world of Japanese 8-cylinders. I bought 5.3 Yukon as used with 7500 miles on it, still in warranty. While I like how this truck drives the idle seems to be unstable.

Problem:

When I stop this 2018 5.3 4x4 6-speed Yukon SLE at the traffic while transmission is in Drive (fully warmed up engine) the idle is fluttering (feels like hear misses a beat, tach needle moves a tiny bit too).

 

I am sure that dealer will not detect anything or see anything and classify all is normal, however 2019 Tahoe 5.3 that I drove in is butter smooth. I am wondering if there are ways for me to narrow down the problem with idle. I know it could be dozens of things from leaky intakes to spark plugs or injectors. I hope this community points me to the areas to check. 

 

Thank you in advance!

[Lsgun1]

Its normal. Unless its going up by hundreds of RPMs don't concern yourself with it. I think its because they idle down so low, mine will go to about 500rpm, all the toyotas and nissan V8s I've been in idle up around 800rpm

[dvzzz]

This is a good point to know, 500 RPMs is certainly low. I have test-drove two other trucks in the past 5 days 2019 Tahoe 5.3 with 17 miles on odometer and 2017 Yukon XL 5.3 with 9,000 miles. I had to check if they were running on idle in D at stop, that how smooth they were, these engines can run butter smooth, I now know. I do not think mine fluctuates several 100s RPMs but it is very very tactile and noticeable, you actually feel like you are going over a bump except you are standing. This sensation is super unpleasant and my wife is now mad in this $59,000 truck, it reminds me of a Soviet Lada from 1980 era, except with those people were happy if they started at all.

Local independent ASE mechanic checked my truck and said indeed he felt it, no codes though. He told me "GM will wear you out on this one, they will keep sending you back with "no fault found" until you give up and trade-in the truck it is much cheaper strategy for GM than paying for extensive troubleshooting because, you will be losing money not GM". I like how quiet the truck is, the looks and want to own an American product if it is fixed but looks like nobody can win the battle with the mighty old GMC. 

I am taking it to the dealer on Thu and let the games begin