6.2L Rough idle and poor low RPM response

[tj40371]

Our 2023 exhibits the same characteristics from time to time, but much more prevalent in the first few thousand miles (like nearly all the time). Dealer never found anything wrong and now at 17000 miles it is mostly smoothed out.

 

[apex944]

Our 2023 exhibits the same characteristics from time to time, but much more prevalent in the first few thousand miles (like nearly all the time). Dealer never found anything wrong and now at 17000 miles it is mostly smoothed out.

Thx, good to know. I'll have dealer take a look and then cross my fingers if they dont fin anything.

 

[jbooose]

I experienced the same rough idle issues you described when I took delivery of my 2021 Yukon Denali. It was definitely a rough idle and you could feel the engine and car slightly vibrate/shake. It did not occur all of the time though and I always used the correct octane fuel. If I applied just a bit of throttle to raise the RPMs up by about 100-200, it went away.

Dealer looked it over but said because there were no codes there was nothing they could do. They also told me they could not adjust the idle speed without a real "issue".

I now have about 34K miles on it and it rarely, if ever, happens now. Hopefully yours will go away too as seems to have happened with me and others.

 

[apex944]

I experienced the same rough idle issues you described when I took delivery of my 2021 Yukon Denali. It was definitely a rough idle and you could feel the engine and car slightly vibrate/shake. It did not occur all of the time though and I always used the correct octane fuel. If I applied just a bit of throttle to raise the RPMs up by about 100-200, it went away.

Dealer looked it over but said because there were no codes there was nothing they could do. They also told me they could not adjust the idle speed without a real "issue".

I now have about 34K miles on it and it rarely, if ever, happens now. Hopefully yours will go away too as seems to have happened with me and others.

Thanks. I just did my first real "tow" this past weekend. 20' steel enclosed with car. About 5500-6000 lbs I would guess. At lower RPMs (even way above idle) it does feel rough. Just doesnt feel smooth at all with part throttle loads.

 

[WalleyeMikeIII]

Thanks. I just did my first real "tow" this past weekend. 20' steel enclosed with car. About 5500-6000 lbs I would guess. At lower RPMs (even way above idle) it does feel rough. Just doesnt feel smooth at all with part throttle loads.

It is possible this is transmission shudder vs. engine...worth taking it in and ask service manager to take a ride w/ you.
Techs can hook up diags and drive it, or have you drive it, and monitor things...Misfires are reported as are fuel trims, and a bunch of otther stuff...

 

[apex944]

Yup, its time to gather some real data.