Newbie with 2016 Tahoe rough idle

[Axeman417]

Hello everybody, I'm new here. I thought I'd skip the intro thread and go straight to the point. I apologize if the following topic has been beat to death, but I didn't see any recent enteries and I'm becoming very frustrated.

Here's the story:

Last summer we purchased a new black Tahoe LS. The car drove fine, but I was never happy with it since it wasn't exactly what I wanted, so I sold it. I then purchased a slate gray Tahoe LT with the luxury and destination packages from GM's Factory PreOwned Collection website. It's exactly what I wanted at a price I could afford. I took a chance on purchasing the vehicle(former rental) from across the country because I figured if there was anything wrong with it, it was still under warranty. Plus it only had 13k miles on it, so what are the chances something would go wrong with it.

WRONG!!!!! Rough Idle. The vehicle had a rough idle when stopped and in drive, such as being stopped at a stop sign or red light.

I took it to the Chevy dealer I used to go to and they gave me the runaround, and told me the rough idle was normal for that vehicle. I guess they forgot I previously had a 2016 Tahoe. That's why I "used to " go to them.

I took it to a different dealership, and they immediately mentioned a service bulleting regarding the engine mounts and shims. It seemed to help a little bit, but it was still there.

I took it back the following week and they changed the engine mounts completely, but called me back and said it was still idling rough. They told me they were going to scan it with a "picoscope" to determine where the vibration was coming from. Currently our Tahoe is still at the dealer because they had to order a longer censor for the picoscope. But based on all the stuff I've read on the internet, I don't expect too much. It seems like this issue isn't exactly uncommon with 2015-16 GM Suv's and trucks.

I'm very frustrated. i sold our new Tahoe with no issues and some equity, for a used Tahoe with issues, and now I'm upside down . The rough idle isn't horrible, but I feel like an idiot. I had no idea something like this could happen.

Anyone else experiencing something similar?

 

[chicagofan00]

I have the rough idle but it isn't at every stop I make so it hasn't honestly bothered me much and haven't brought it in yet.

It sounds like the current dealership is trying to do right by you and get it fixed. It's most definitely a bummer to have to be going through it but give them a chance and perhaps all will be good in the end.

 

[Axeman417]

I have the rough idle but it isn't at every stop I make so it hasn't honestly bothered me much and haven't brought it in yet.

It might be the same thing as mine. The vibration is minor, and not always there. It seems to develop after the vehicle is driven about a mile or two. My biggest concern is that it will get worse.

 

[chicagofan00]

Mine hasn't worsened after 27,000 miles, if that makes you feel any better...lol.

 

[Axeman417]

Actually it does, a little bit....lol.

 

[Tahoe14]

Axeman, I also did a lot of research and unfortunately it sounds like a lot of owners across the board are experiencing the same thing. It looks like the motor mounts were aligned or replaced which helped very few or they just said screw it and put in a tune to increase the idle which helped most if not all. Many just gave up and are living with it which they should not have to. Maybe the scope will turn up something. Good luck and keep us posted.

 

[Axeman417]

Thanks. Will do.

 

[Miami-Dade]

Is your a/c constantly on?

I keep mine constantly on and do not notice any rough idle..Not sure if that has something to with it but I have never had the a/c off since I brought the Tahoe home so do not know if the idle is different with it off..Ever since the 70's I just set the a/c and forget it and never shut it off.

 

[nj16yukon]

For those experiencing this, can you describe exactly what you're feeling? I just bought a 16' XL Denali a few weeks ago. When stopped, I notice a little vibration or "gurgle" that happens every few seconds. However I'm not seeing any movement in the tach when it occurs. I wasn't sure if this was normal behavior for the 6.2, or if this is the rough idle that others are describing.

 

[Axeman417]

Is your a/c constantly on?

I keep mine constantly on and do not notice any rough idle..Not sure if that has something to with it but I have never had the a/c off since I brought the Tahoe home so do not know if the idle is different with it off..Ever since the 70's I just set the a/c and forget it and never shut it off.

I'll have to try that.

 

[Axeman417]

For those experiencing this, can you describe exactly what you're feeling? I just bought a 16' XL Denali a few weeks ago. When stopped, I notice a little vibration or "gurgle" that happens every few seconds. However I'm not seeing any movement in the tach when it occurs. I wasn't sure if this was normal behavior for the 6.2, or if this is the rough idle that others are describing.

It's pretty much what you've described. If you've ever had a vehicle shut off on you at a stop. It's kind of like that, but not to that extreme.

As far as the tach, it is barely noticable. But it only happens under 500 rpm's.

I used to have a Chevy Colorado 1st gen that did something very similar, but a throttle body cleaning took care of the vibration completely. As a matter of fact that's the first thing I did to this vehicle, but it didn't do any good.

Had I not had a 2016 Tahoe before this one, I probably wouldn't be making such a big stink about it. But there's an obvious difference. Seems like a quality control issue. "These engines just run like this", is a bunch of BS. I've experienced what this engine is supposed to run like first hand.

We'll see what the dealer tells me tomorrow. The service advisor already hinted at the vehicle being within the manufacturers acceptable vibaration level.

 

[Axeman417]

Well it's been a week since the service advisor told me they would need to order a longer sensor for the pico scope. He gave me the option of picking it up and they would call when the part came in, or leaving it at the dealership. I chose to leave it at the dealership, believing that they would probably never call me to bring it back in.

I called today for an update, and they told me the part hadn't arrived yet. Since there's no urgency to get the vehicle back on our part, I told him I would continue leaving it until the part gets there.

....to be continued.

 

[2016YUKONSLT]

Well it's been a week since the service advisor told me they would need to order a longer sensor for the pico scope. He gave me the option of picking it up and they would call when the part came in, or leaving it at the dealership. I chose to leave it at the dealership, believing that they would probably never call me to bring it back in.

I called today for an update, and they told me the part hadn't arrived yet. Since there's no urgency to get the vehicle back on our part, I told him I would continue leaving it until the part gets there.

....to be continued.

You should take the spare key fob, go up to the dealer and move it in front of the service bay to bring it to their attention until they feel some urgency...lol

 

[Axeman417]

Three weeks since I first took my Tahoe in to the dealer, and they told me they're still waiting for the Picoscope part. So i finally picked it up my Tahoe from the dealer. It had been sitting there in their back lot, untouched. The service advisor told me the part they are waiting for hasn't come in. He told me he would call me as soon as the part comes in. I'm not going to hold my breath.

At this point my options are...
1. Leave it as is. Honestly it's not that bad. I just expected better.
2. Find another dealer....again.
3. Just wait and maybe this dealer will call me.......eventually.

 

[revolt]

Heard the same issue over a buddy here and he just get used to it.

 

[chevypat]

I had the same issue on my 2016 LT. It kinda feels like its kicking the V4 on idle to save gas? (Hopefully that's the concept), But the cluster still says V8. Its not worse but I can feell the vibration. Currently at 32k.


Sent from my iPhone using Tapatalk

 

[Axeman417]

*****UPDATE*****
Completely unexpected. The dealership called me two Thursdays ago to tell the the part for the Picoscope came in, so I took it back in to the dealer this past Tuesday. They still haven't found the issue, but he told me he had a GM field engineer helping their tech.

 

[Axeman417]

I had the same issue on my 2016 LT. It kinda feels like its kicking the V4 on idle to save gas? (Hopefully that's the concept), But the cluster still says V8. Its not worse but I can feell the vibration. Currently at 32k.


Sent from my iPhone using Tapatalk

Exactly. At first I didn't realize there is an indicator that tells you when the vehicle is in V4 mode. But the vehicle still shows V8 when the rough idle exists. Either way, my previous 2016 Tahoe LS didn't vibrate like this. So it seems like a quality control issue. Unless the LS models aren't equipted with AFM.

 

[Axeman417]

*****Update****. Dealer indicated GM wants them to install a new set of shims, on the motor mounts.

 

[Axeman417]

Alright, so just to end this thread, in case anyone has the same issue in the future. They put new shims. According to their Picoscope diagnostic tool, the trembling was reduced to within the "acceptable range". To me it's not perfect, but It's not horrible. Since I purchased this vehicle used, and I didn't notice the condition on the test drive, I don't have a leg to stand on.