issue 2014 rough engine idle

[Cnmx27]

My 2010 did the same, luckily at my job my boss worked for gm truck development for 14 years. The problem is with the fuel/alcohol sensor/calibration. It's changing the timing slightly to compensate for ethanol or gasoline. Mostly just annoying. But my 2010 had it real bad and 4 different dealers told me it was fine. Well, called gm corporate got a case number explained what the problem was and the fact I've been a mechanic for 18 years, they made my local dealership actually look at it and by that point it had burned 3 of my pistons. They fixed under warranty. My 2014 gmc is starting to do the same thing. On the older 5.3 vortec it was simply a matter of a software update. Don't know about the new engine.

[Matrixticity]

Well, here it is 2016 and still there hasn't been a fix for the rough idle issue. My truck has 34000 miles and from weeks after buying it I've had the issue. With just a few thousand miles on it and after driving a steady 65 mph I stopped at a rural redlight and the engine idled down so low it was stumbling as if about to stall out. This happend twice and when taken into the dealer they told me no codes kicked and nothing could be found. Once I complained several times while in for oil changes, they informed me they found a bulletin to shim of engine mount. Had the truck another day but this didn't help the issue at all. I just recently took it to a different dealer and they claim they don't note an issue. I explained that it generally happens when sitting in drive at a stop light and engine will idle smooth then stumble out for a few seconds then run smooth again then same issue. But they did not feel there was anything they could do to remedy this issue. I have a $40k truck and have to watch tach to make sure not stalling in traffic.

Am I just not talking to the right people about this? My bumper to bumper is about to expire.

[HondaHawkGT]

Is your truck acting similar to this:

 

 

 

His idle dips were caused by a bad O2 sensor. A service technician with a scanner could watch the signal from the O2 sensors to identify whether something is wrong with them. Same if it were a fuel pressure issue, catalytic converter issue, etc. You need a real-time scanner to identify it.

 

I had a rough idle on occassion. It's always been due to bad fuel. I stopped filling my truck with that 87 octane junk and never looked back.

[Jsdirt]

I too switched to 93, mainly because my truck would nearly knock itself to pieces with any kind of a load on the engine.

 

Still idles somewhat rough. Same as when it had 2k on the clock. Just the way they built 'em today.

[ic3man5]

Well, here it is 2016 and still there hasn't been a fix for the rough idle issue. My truck has 34000 miles and from weeks after buying it I've had the issue. With just a few thousand miles on it and after driving a steady 65 mph I stopped at a rural redlight and the engine idled down so low it was stumbling as if about to stall out. This happend twice and when taken into the dealer they told me no codes kicked and nothing could be found. Once I complained several times while in for oil changes, they informed me they found a bulletin to shim of engine mount. Had the truck another day but this didn't help the issue at all. I just recently took it to a different dealer and they claim they don't note an issue. I explained that it generally happens when sitting in drive at a stop light and engine will idle smooth then stumble out for a few seconds then run smooth again then same issue. But they did not feel there was anything they could do to remedy this issue. I have a $40k truck and have to watch tach to make sure not stalling in traffic.

Am I just not talking to the right people about this? My bumper to bumper is about to expire.

 

Inspect the Intake valves, they are probably caked with oil.

[Jesse Davidson]

 

Inspect the Intake valves, they are probably caked with oil.

I think every GM does this, mine does it too, maybe not quite as bad? but it does it.

[Jsdirt]

All the new Direct Injected engines do this - no fuel present to keep them clean with DI.

[ic3man5]

I did seafoam spray for the intake valves and gained 2-4MPG and a smoother idle. Only have 4500 miles on the truck so far. Have a catch can on order and going to install it asap.

[Evan48]

I had my 2014 Sierra into the dealer to complain about this issue and they told me that it was clogged injectors from bad gas. They told me I needed an injector flush for $300 to correct the issue.

 

Apparently it's not covered under warranty.

I said, ok well when something breaks, you can fix it under warranty, to which he replied "well actually if you skip routine maintenance, any issues that arise will not be covered under warranty"

Funny, when I checked the maintenance schedule, I didn't see anything about injector service at any mileage, certainly not as low as 20K.

 

They sent me a few survey e-mails so I really let them know what I thought, they got back to me with apologies but no solutions. I'm pretty pissed off and won't be buying another GM product, that is for sure. $50k for a truck that runs like crap.. I wouldn't have this problem with Ford.

[HondaHawkGT]

I had my 2014 Sierra into the dealer to complain about this issue and they told me that it was clogged injectors from bad gas. They told me I needed an injector flush for $300 to correct the issue.

 

Apparently it's not covered under warranty.

I said, ok well when something breaks, you can fix it under warranty, to which he replied "well actually if you skip routine maintenance, any issues that arise will not be covered under warranty"

Funny, when I checked the maintenance schedule, I didn't see anything about injector service at any mileage, certainly not as low as 20K.

 

They sent me a few survey e-mails so I really let them know what I thought, they got back to me with apologies but no solutions. I'm pretty pissed off and won't be buying another GM product, that is for sure. $50k for a truck that runs like crap.. I wouldn't have this problem with Ford.

 

HAHAHA you think Ford would handle it differently? You might want to do a little google research and see how Ford dealers handle a rough idle complaint. I'll tell you what they do: scan for codes, look over the engine bay for obvious things, and hand you the keys back while telling you "Ford says it's normal".

 

 

My advice to you is to eliminate the easy things you can do yourself. As long as your truck isn't throwing a code and runs, rough idle or not, you're probably not going to get a quick fix at a dealer. I certainly wouldn't pay a dealer to do an "injector flush", which sounds like a BS dealer scam.

 

Install an oil catch can

Try running an injector cleaner like Chevron Techron or Gumout Regaine All-in-One (the one that says PEA on the bottle)

Remove and inspect your spark plugs for abnormal combustion conditions

Get a BG Induction service or buy a product like CRC GDI IVT cleaner spray

 

A warm rough idle is an extremely common occurance with many vehicles. I've had it with nearly every vehicle I've owned at one time or another. There are plenty of guides on troubleshooting it. Unfortunately a dealer isn't going to troubleshoot it for free for you, but some will try to sell you services like an "injector flush".

 

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

[scottie350]

I just bought a 2014 silverado crew cab last week. I noticed a minor shake in the engine while idling (not 100% of the time). Ive felt this in older trucks that Ive owned but figured a brand new truck wouldnt do this. My question is, is this normal to feel this? if so, at what point does normal idle shakes turn into some i should be concerned about? I was under the impression that i shouldnt feel any shakes (minor or not). I have set up a appointment with my dealership, but i want to be prepared when i go in. Also, Im hearing a noise like a belt noise coming from the engine especially when i and parked in a drive through next to a wall. Should i be hearing any ticks form belts? Am i being too picky?

 

Any help would be great

Jason

Throw high octane in it, and see if it smooths out. It's been found that these engines are pulling knock on 87 octane, at 11:1 compression, it's understood why, a lot of ppl have been finding running 89-91 octane made the truck run significantly better.

 

That doesn't help, bringer to the dealer that's what u r warranty is for man

 

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[scottie350]

Also I'll tell u right now, my 15 has the loudest aftermarket exhaust and it doesn't shake a damn thing lol take it to a different dealer

 

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[scottie350]

And as stated, there is some things you can do, injector flush being one, I'd do it immediately after installing a catch can( these DI engines basically require them, or they should, oil going back through the system and bungling up lifters is common place with DI). and run at least 89 octane. All assuming any check of engine codes and stuff uve had done ect turns out fine. Once you've done the flush and changed fuel, go from there

 

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[scottie350]

I did seafoam spray for the intake valves and gained 2-4MPG and a smoother idle. Only have 4500 miles on the truck so far. Have a catch can on order and going to install it asap.

4800kms on mine, wish I had gotten a catch can put on right away when I bought it at zero, It'll be there by the time.i get home from work in a couple weeks, and then intake cleaning will ensue moments after install.

 

 

 

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[HondaHawkGT]

I though I'd pass this along. GM recently posted a reminder about the importance of quality fuel with adequate additives.

 

http://sandyblogs.com/techlink/?p=5563

 

All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the “Lowest Additive Concentration” (LAC), which is the EPA and CGSB minimum detergent treat rate requirement. GM strongly recommends the use of TOP TIER Detergent Gasoline. Many gasoline retailers provide fuels with lower-quality additive packages that can build up deposits on fuel injectors and on intake valves. (Fig. 15) Fuel injectors that become restricted with carbon deposits over time result in an incorrect injector spray pattern. The deposits on intake valves reduce fuel economy by creating a porous surface that collects wet fuel, affecting the air to fuel mixture in the cylinder and releasing fuel late in the combustion cycle, which leads to increased unburnt hydrocarbon (HC) and carbon monoxide (CO) emissions.

 

 

 

The carbon deposits can build quickly if a catch can isn't installed. Oil vapor and combustion gases get pulled into the intake by way of the PCV system. The carbon can end up increasing the chances of pre-ignition, causing the engine to adapt by pulling timing especially on regular 87 octane. Due to the ECU pulling timing, it causes poor fuel economy and power, as well as creating issues like rough idle.

 

Injector cleaner containing PEA can help clean combustion chamber deposits and the injector orifices. Top Tier fuel has more detergents than non-TT fuels, but the minimums required by the Top Tier spec is still quite low, varies wildly between different brands, and is not enough to deal with an engine that's constantly pulling PCV by-products in.

 

An oil catch can will also help reduce carbon deposits:

http://www.gm-trucks.com/forums/topic/154204-oil-catch-can/