Rough idle when coming to stop

rilcoat · May 22, 2016

I have a 2015 RC LT with the rough idle issue in gear at stop with brake on and yes I have had the shims put into my motor mounts at the dealership. The truck has 3000 kms and did it from new. It has helped. I do get it now and then which I think if I bump the idle a bit it should go completely away. I had to tell my dealer to do the shims because they did not know about it. They did research it and found the service bulletin.

GMCustomerService · May 23, 2016

Our new 2016 Silverado(500km) has a somewhat rough idle also when parked. I notice the tach shimmy and it feels like the truck has a miss or too low of a idle. I'll be bring this up when I go for my first oil change to see what they have to say. Maybe like with our Canyon I had to tell them what needed to be fixed after their recall screwed up the steering system.

Something else I noticed is when you start up the air conditioning there is IMO a old PCV valve oil smell comes out, my wife says its still new but I remember that smell from the olden days. We have only had the truck for a week now and sure hope it goes away.

Hi Alter,

I regret to hear you are experiencing these concerns with your new Silverado. If you would like us to assist you when you eventually bring it in for an oil change, feel free to send a private message our way.

Have a great day.

Julianne M.

GM Customer Care

rilcoat · May 29, 2016

Alter, on 20 May 2016 - 03:49 AM, said:

Our new 2016 Silverado(500km) has a somewhat rough idle also when parked. I notice the tach shimmy and it feels like the truck has a miss or too low of a idle. I'll be bring this up when I go for my first oil change to see what they have to say. Maybe like with our Canyon I had to tell them what needed to be fixed after their recall screwed up the steering system.

Something else I noticed is when you start up the air conditioning there is IMO a old PCV valve oil smell comes out, my wife says its still new but I remember that smell from the olden days. We have only had the truck for a week now and sure hope it goes away.

Ignore GM customer service. They are not and I repeat, they are not going to help you in any way. There are far too many people in this forum with the same issues as us and more with other concerns and GM is turning a blind eye. As long as we keep buying the product, they will not change. I personally know after my recent dealings with GM customer service and had no help from them, I will not support GM again. Lean on the guys in the forum for fixes and the hell with GM customer service.

HondaHawkGT · May 30, 2016

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TonyM16 · June 7, 2016

I have a 2014 GMC Sierra 1500 5.3L. It has a very rough idle AT TIMES. Other times, I don't even notice it running. The idle gets rough enough that my wife has actualy asked me if my truck was "missing". I'll try Sea Foam in intake and see if that helps. Will post if it does.

holty · June 7, 2016

Add another 2016 to the rough idle list. My truck has 900 miles on it. Idle has been intermittently rough since it had 10 miles on it.

SierraMyst · June 9, 2016

Same here 2016 5.3L, rough idle while stopped in Drive. 3500 miles on the truck.

The more and more I think about it, the more I regret not getting a 6.2L.

The shift TSB all apply to the 6.2L, there's no rough idle for a 6.2L.

b1gted · June 9, 2016

my 2016 occasionally is rough at stop lights. I notice it is below 500 rpm when it is doing this. I would think the computer would bump up idle if it senses this roughness. Guess not!

OmniCamaro · June 9, 2016

Are you me?

You just described exactly what I'm having AND I had to drive a loaner for the last 2 months that didn't do this at all.

Yea.. try this out though, mine will idle rough (like.. omg is this thing going to stall out?) rough in DRIVE and ONLY when warm. If its cold, no problem, if its rolling, even a little bit? no problem, reverse? no problem. ONLY drive.

Is that that what you're seeing?

You should see the water bottle I keep in my cup holder. It's a trip.

If its nothing actually WRONG.. I can put up with this, my concern is that there's some component thats gonna blow at 60,001 miles and put me like $20k in the hole for a new engine.

EXACTLY what I'm seeing with my brand new 2016 5.3gas. Feels like a miss and the water bottles are a great example. Easy to see with them in there. Don't like it at all!

Sent from my iPhone using Tapatalk

tylerrmack · June 10, 2016

I have a 2016 1500 6.2l. Lifting the hood the engine vibrates pretty good. The mounts absorb most of it. But still vibrates more than I would think a engine should these days. Anyway, During idle its ok, except every 3 seconds or so it seems to stumble. Just slight enough to be noticeable and annoying. If it was more steady I would chalk it up to a big engine and just tell myself "its the power!", then I would feel good and move on. It can be intermittent though. I took it in and of course it was being calm that day, which also happened to be a 100 degree day. Could that have something to do with anything? Anyway, that was Saturday and they stated all was fine. Then started up on Monday morning for work and incredible rough, no power (limp mode). P0300 Misfires Engine light blinking. Towed to dealer. #2 plug fouled, soaked it gas. Dealer said "bad plug, just happens". This was with 1k miles. Really?! Been having rough idle issue then this happens, but just bad plug. Maybe there is something else going on! Stumbling again every few seconds and noticed a little needle fluctuation, so going to go back when I get a chance. Tech drives a older truck so Im afraid everything feels smooth to him.

HondaHawkGT · June 10, 2016

Actually modern engines have had a increasingly common tendency to have some vibration during warm idle. Manufacturers are under pressure to cut idle fuel consumption down to the least amount of fuel possible. If they can cut idle fuel consumption by 5 grams of fuel by making idle slightly low (borderline too low), they will do it. Honda has been in the news for vehicles that owners complain idle too low and rough. As long as the engine doesn't stall, who cares. AFM is far far far more annoying than an intermittent warm idle vibration, yet some guys want AFM to come on more often than GM intended. Kind of ironic since the engine mounts on the 14+ trucks are tumed for AFM vibrations yet are probably a big culprit for exacerbating a low idle vibe.

Willshire · June 10, 2016

19000 miles and no issue with idle. 87 octane since new

tylerrmack · June 13, 2016

Took off my air box today to look at the pcv hose to see if it was overly oily, couldnt tell much from it. But opened the throttle body plate and looked in with a flashlight and saw a pool of oil behind the plate. I know the pcv puts a little oil back in but it was a pool. Probably easily a tablespoon or more sitting right behind the plate. Is it ok or normal to have this much. Seems excessive. I know people like catch cans but this seems more than what even those are designed for (enough to pool in the throttle body, not just coat the valves). I again i have a intermittent rough idle/shutter and already fouled a plug at 1k miles. Pressung on the gas in park to increase rpm, i can still feel something like a miss/shutter at 1000rpm

Brianibew · June 13, 2016

Your right, it should be smooth as silk at 1k rpm. Take it in, let the dealer deal with it. Also, it's not uncommon for oil to pool in the intake. A good catch can should take care of most of that.

dbt1127 · June 13, 2016

Well, all I can say is that I'm disappointed. I traded my '14 double cab in 2 weeks ago for a '16 crew cab. My '14 ran and drove great. No issues. About 15 minutes in from the drive home I experienced the rough idle at a stop light while in drive. I took the took in about 5 days later and they shimmed the mounts....without even asking me. Not that I would have said no, but seems a bit drastic for a brand new truck with less than 300 miles on it. Anyway, I was hopeful that would fix the issue. I was wrong. All it did was put a band-aid on it.

I took the truck back exactly a week later to explain that the issue was still there. Granted it is not as intense and it doesn't happen all the time, but when it does the whole damn seat shakes. I drove around with a manager, the same one who test drove my truck after the "fix" and he basically acknowledged that there was a vibration when stopped but said there was nothing they could do for me. Most if not all the new trucks do this is what he said. I highly doubt this. Not sure what my options are except to keep bringing the truck back in and complaining. He told me GM was aware of the issue and that they are working on a fix.

They better hurry up......