2014 6.2L Slight rough idle when cold - Anyone else have this?

[Nickshu]

I have not taken it in yet to my dealer. 2014 w/ 6.2L engine and only 750 miles on the odometer. When the engine is cold and during warmup I notice the idle is somewhat rough. I can feel it in the driver's seat but the truck still drives normally w/ no hestitation or stumbling I can notice. Seems to go away once fully hot. Anyone else have this? Normal??

[bass mechanic]

do a search for engine or motor mounts, its a known issue. your dealer should be able to find the info on it.

[bills]

I have the same issue and I'm bringing my truck to the dealer next week to check it out. It doesn't seem to happen all the time. At first I thought I may have gotten some bad gas, but that has now been ruled out.

[chuckwi11]

Rough idle or a "rumble"? If it isn't throwing a code then it's likely not electronic or a sensor. I know that the 6.0L in my TBSS will "rumble" at idle and most of the TBSS guys I know seem to believe it's just the "beast shuddering"... the 6.2L in my G8 would rumble as well. How bad is it and does it happen any other time than just at start up?

[Nickshu]

Not too bad and only when starting up and during warmup. After that it idles smoothly. Like the post above mine also does not seem to do it all the time, just sometimes, which means if I take it in they may not be able to reproduce it.

[fondupot]

My 5.3 has had the idle vibration TSB done a couple of times. At first I could feel a very prominent vibration in my truck at idle. Now its a lot better, still not perfect. I found that its better using mid grade 89 octane gas. Are you using premium 91/93 in your 6.2?

 

Could be that you need to have the TSB done as well.

[Newm]

My 6.2 has a slight rumble at idle during a cold start. Nothing to pronounced really and my thought is it's just a big V8 that is cold. Clears right up as soon as I start moving or has idled for 30-45 seconds. Only does it after it has sat overnight.

[GMCustomerService]

I have not taken it in yet to my dealer. 2014 w/ 6.2L engine and only 750 miles on the odometer. When the engine is cold and during warmup I notice the idle is somewhat rough. I can feel it in the driver's seat but the truck still drives normally w/ no hestitation or stumbling I can notice. Seems to go away once fully hot. Anyone else have this? Normal??

 

Hello Nickshu,

My apologies to hear that you have concerns with a rough idle when the engine is cold. What I can do is take your information and document this concern in our system and if you'd like I can reach out to your dealership on your behalf. I understand that this has been intermittent and you may not want to take your truck into the dealership just yet. However, if you'd like my assistance you may reach out to me via private message with your contact information and VIN.

Best,

Andraya

GM Customer Care

[Rewillia]

my 6.2 does it sometimes and I'm inclined to believe its the gasoline. here in Alaska 90 octane is the highest to be found

[Nickshu]

I am running 91 octane fuel. I generally use Shell V-power gas. May try different fuel. Thanks!!

[Rewillia]

I am running 91 octane fuel. I generally use Shell V-power gas. May try different fuel. Thanks!!

Not a lot of choices up here and 90 Oct is the highest that can be found. That said, haven't had any real/significant problem just ever so often I get slight rough idle but it clears once under a load/accelerating.

[Sooperdave]

Smooth enough for me.. Mine is smoother than my G8 was but not as smooth as my TBSS.

['01LS1]

Why not get it fixed if it is not baby butt smooth?

 

My guess is they are only going to say it is normal operation. My 2013 6.2(old version) does the same at start up. Idles a little high initially & then low before settling out within 30-45 seconds.

 

The Shell fuel should be fine. Have noticed they label it as 93 octane around here, but another station(Road Ranger) dropped theirs from 93 down to 92 but are still top tier certified.

[Nickshu]

My guess is they are only going to say it is normal operation. My 2013 6.2(old version) does the same at start up. Idles a little high initially & then low before settling out within 30-45 seconds.

 

The Shell fuel should be fine. Have noticed they label it as 93 octane around here, but another station(Road Ranger) dropped theirs from 93 down to 92 but are still top tier certified.

This is my expectation too... I'll waste a day of my time and they'll just call it a "normal characteristic". BTDT.

[Sooperdave]

Why not get it fixed if it is not baby butt smooth?

Cause I'm not a ninny when it comes to little shit like this. It doesn't bother me. I don't expect a 420/460 normally aspirated engine to be baby butt smooth.