drpete12, Any update on your situation? I have a 2015 Chevy Tahoe LT with what sounds to be the exact same problem. First they added the 3mm shims to the motor mounts with no improvement. This week they replaced the motor mounts. I haven't picked it up yet so I can't say if it's really fixed.

 

I also have the 2015 Suburban

It has been back to the dealership 7 times.
They have replaced the shims twice
They have replaced the transfer case

This last time it was in the shop for 43 days. They said they are going to replace the motor mounts.

Got it back and it was good for about 4 days then the shaking was back worse than ever. Before it would only shake while you have it in drive. Now it shakes if it is in park or drive.

This is not normal, we have driven the same model rental cars and they did not shake.

Also we are experiencing a lag or hesitation when accelerating when shifting between 1st and 2nd gears. There are too many people having these same issues and I cannot believe there has not been a fix for this yet!!

If there is anyone out there that could we would appreciate the help!!!

Thank you

 

RoughIdle, my vibration problem went away after the motor mounts were replaced, but it has now returned with a vengeance. We are proceeding with a Better Business Bureau claim (Lemon Law), again. Have you tried this in order to get a new vehicle or a vehicle buy back?

This is not the only vibration related issues we've had. We also had a severe vibration when traveling at speeds in excess of 70 mph.

 

Hi MonkeyDaddy,
The vibration has gotten worse since driving for a few months. We noticed the shaking was not as bad around the beginning of March and then we had no cold air. The condenser had a small hole and it was leaking so the AC was not coming on. It took about 1 1/2 weeks to get the car back because the condenser was on back order. Once we got the vehicle back the car shakes worse than ever.

Not sure if a Lemon Law Lawyer can help we have 53k miles on the vehicle but we purchased the 100k power train warranty

 

We also have shaking when we travel 70-80 MPH....

 

Welcome to the forum.

The powertrain warranty should cover it as the last time I checked, the engine was part of aforementioned powertrain.

You could look into your state's Lemon law as they are all different.

 

All,

It appears I'm also being claimed as a victim in this ubiquitous problem across suburbans and tahoes. Our 2017 suburban is now in at the dealership for "Hard idle," and a "hard cold start" code. The dealership is saying there is a misfire in the cylinders somewhere (perhaps a plug or wire) but the truck is also periodically downshifting hard in lower gears at lower speeds--45mph and under (from 3rd, 2nd, 1st gear, etc.)

I'll try to keep everyone posted. I'm equally encouraged and concerned to see the same issue happening with similar models across the board. I also am not opposed to citing and attempting to enforce the lemon law if it comes to that. My parents successfully used the lemon law to force a buy-back when I was a kid on a Chrysler PT Cruiser (03, I believe).

All the best,
Billy

 

Check your evap system, it can cause it the rough idle