2016 rough idle

[Fred_e81]

I've searched and I have used some if the suggestions but nothing. With that said, I have a 16 Tahoe that I purchased recently. Took it home found it had the rough idle that seems to be pretty common, from reading the forums. I've checked plug wires, sprayed sea foam, checked alternator. Nothing seems to fix it.

I've heard that getting a tuner and bumping up the idle would do the fix along with getting rid of the AFM. Has anyone actually used a tuner like Diablo to do this? I'm not really looking for performance just wanna bump up rpm to get rid of the rough idle, get rid of AFM maybe that's the issue as well, better gas mileage and maybe mess with shifting points. Has anyone done this? What were the results with what tuner? Thanks in advance for any input.

 

[BobMc]

Take it to the dealer--there is a TSB (?) out concerning motor mounts.

 

[Yeep740]

I just bought a '16 Denali and took it back to the dealer for a few things (480 miles) and one of them was a rough idle. Mike is when I am in gear like at a stop light. I described it to the dealer as a "miss" thy said it had no codes and to bring it back when they had more time and they would do an extensive test to see what was causing the miss/vibrations. They said they would add shims to different areas in the vehicle (motor mounts, body points, seat frame depending on what their machine measured during the test. My question is how is a shim going to fix what feels like a miss in the engine?

 

[#1taho]

With problems like these and many people with them, I think I am going to have mind 05 for a long LONG time.

Please let us know how you make out. I am curious how a shim on the body mount will fix a miss feeling

 

[BobMc]

• Date Reported JUNE 08, 2016

• NHTSA Reference #10080684

• TSB Reference #PIP5211E

Description: THIS PRELIMINARY INFORMATION COMMUNICATION PROVIDES INFORMATION TO THE TECHNICIAN THE STEPS NEEDED TO DIAGNOSE AND REPAIR VEHICLES WITH A ROUGH IDLE AND/OR VIBRATION AT IDLE IN DRIVE. THIS CONDITION WILL NOT BE PRESENT IN PARK, OR NEUTRAL.

They replaced motor mounts.
It worked om my 2015i!

 

[Yeep740]

This explains how they "should" be able to fix the rough idle....

http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=196420

 

[Fifty]

Wow that's crazy...

 

[Yeep740]

Been sitting at the airport waiting to pick up my buddy and his wife and his thing shakes like a mofo in park. Bulletin said it only happens in drive or reverse. Awesome....

 

[Fred_e81]

Update.....So last month I got a check engine light. Took it to the dealership where they said that #7 and 8 injectors were not working properly. They replaced both but about 2 weeks later the problem started again. Yesterday I got another check engine light. Took it to the dealership today and I was told that the injectors for cylinders 7,8,1 and 5 were misfiring. They said that within the last 15 days I had over 100 misfires at a cold start. I was told it might be an electrical issue.....we'll see. In the mean time, I'm gonna start looking into the Lemon law.

 

[Fred_e81]

Update....I got a call from my service rep who advised that they did an ohm test on the fuel injectors which turned out negative and they are working as they should. He said there might be a wire from the main harness grounding off and causing the injectors to malfunction. As of now we're standing by for the gm engineers to give direction on where to go from here. I also asked that if even without a check engine light on, they are still getting the misfires and he said yes. Something to think about if you guys take yours to the dealership and they say they cant do anything because they dont have a cel warning light go off. It will still tell them that it has a misfire without that light going off. I'll keep you posted