Rough idle when coming to stop

tylerrmack · July 8, 2016

Deputy,

What was the sensor that was replaced at same time as ecm?

Thomcat · July 8, 2016

Some new trucks that are doing it is probably coming from the torque converter, hence why it won't vibrate unless the truck is put in drive. If it does it in park then its a diffrent issue. Like I said, the mounts are not the source of the problem, they just happen to be resonating to the vibration source.

There is more load on an engine through drag on the torque converter in Drive than Neutral or Park which will aggravate any vibrations. Forward and Reverse gears activate the hydraulic pump(s) used to generate pressure for operation of the band servos. The operation of the pump, (A/C compressor, or alternator) will cause the rpm to drop under the additional load.....the ECM should compensate to prevent this by adjusting the mixture and/or rpm, but anything unexpected in the induction system like an air leak, faulty PCV/EGR valve or bad/borderline temperature or MAF/CAT sensor can contribute to a rough idle. Worst case scenario is a combination of these operating at the upper or lower limits of their specification, not enough to trigger a detectable fault for any one particular sensor, but the cumulative effect is enough to screw up the ECM's fuel management (which always defaults to clean air, at the expense of passenger comfort....[Thank You EPA]) and cause a rough idle. If this is the case and no fault is triggered, the dealer's equipment is not likely to find it.

dbt1127 · July 14, 2016

I'm so fed up with this. Finally got a call back from the dealer after GM set up an appt for me to go in this past Tuesday. I get there and they tech tells me there is nothing they can do and I won't get satisfaction. I had the shop foreman come out and take a look at it. He confirmed the vibrations. didn't even have to drive it, just put it in gear. He said "yup, this is a bad one" but then continued to say there was nothing he could do for me. They can only do what GM tells them to do. This is crazy. I've blasted GM with calls and am waiting for a call back..can't believe the trouble I'm having with this.....

2015Z71 · July 14, 2016

Good luck i had soo many issues i had to take a loose on my 2015 and bought a 2016 and am still having issues.

dbt1127 · July 14, 2016

Good luck i had soo many issues i had to take a loose on my 2015 and bought a 2016 and am still having issues.

what are your issues?

OmniCamaro · July 14, 2016

I'm seeing the rough idle as well in my 2016 Silverado. It's worse in neutral. Almost like a miss.

Another day in paradise[emoji631]

Loupls · July 20, 2016

I have had my truck 2016 Chevy Silverado for about 6-7 days since I purchased it july 6th. It has been in the shop for 7 days. After having step rail installed and the chip in the paint fixed I notice a rough idle when in drive at lights when my foot is on the brake, does not do this in reverse or neutral. The dealer is telling me its normal, I told them to keep the Truck no one should have brand new truck idle like its going to die at every light or intersection. The thing is I don't think they know how to fix it is why they are say its normal. Also have seen the TSB of the fix most say it does not fix just covers up the issue and returns later, what does GM have to say about this? I had driven two different loner trucks no issues. The service guys are telling me its about the flex fuel issue that is why its doing that I call B.S.

HondaHawkGT · July 20, 2016

I have had my truck 2016 Chevy Silverado for about 6-7 days since I purchased it july 6th. It has been in the shop for 7 days. After having step rail installed and the chip in the paint fixed I notice a rough idle when in drive at lights when my foot is on the brake, does not do this in reverse or neutral. The dealer is telling me its normal, I told them to keep the Truck no one should have brand new truck idle like its going to die at every light or intersection. The thing is I don't think they know how to fix it is why they are say its normal. Also have seen the TSB of the fix most say it does not fix just covers up the issue and returns later, what does GM have to say about this? I had driven two different loner trucks no issues. The service guys are telling me its about the flex fuel issue that is why its doing that I call B.S.

If it was the flex fuel TSB your remote start wouldn't work and a service engine light would be on. They could figure it out but it requires a real time diagnostic scanner and enough time to troubleshoot it. That's where the problem comes in... for the amount of time it would take, it's not worth it for them. They give the same line every manufacturer's dealer will give you: "It's normal". Just google any brand plus a phrase like vibrating engine or engine shaking at idle. Part of the problem is they are required to minimize idle fuel consumption and exhaust emissions, which means setting the idle rpm as low as absolutely possible. Honda came close to a lawsuit recently for just that kind of issue.

Loupls · July 21, 2016

If it was the flex fuel TSB your remote start wouldn't work and a service engine light would be on. They could figure it out but it requires a real time diagnostic scanner and enough time to troubleshoot it. That's where the problem comes in... for the amount of time it would take, it's not worth it for them. They give the same line every manufacturer's dealer will give you: "It's normal". Just google any brand plus a phrase like vibrating engine or engine shaking at idle. Part of the problem is they are required to minimize idle fuel consumption and exhaust emissions, which means setting the idle rpm as low as absolutely possible. Honda came close to a lawsuit recently for just that kind of issue.

Well now they say they are replacing the motor mounts,but from everything I've read this will only mask the issue, even though the one the higher ups in the company said its not a engine issue I am now questioning everything they are telling me. Mainly because I had to google it to find the TSB about this. There service tech did not have clue. I have driven this truck for about 6 days and its brand new, this is totally bad business, I am going to rethink my customer loyalty to GM at this point. I have driven Chevy or GM for 30 years.

dbt1127 · July 21, 2016

Well now they say they are replacing the motor mounts,but from everything I've read this will only mask the issue, even though the one the higher ups in the company said its not a engine issue I am now questioning everything they are telling me. Mainly because I had to google it to find the TSB about this. There service tech did not have clue. I have driven this truck for about 6 days and its brand new, this is totally bad business, I am going to rethink my customer loyalty to GM at this point. I have driven Chevy or GM for 30 years.

I had the shims done.....I still vibrate like a mother f'er at red lights or in traffic....it's horrible. I have a case open with GM about this. I have taken my truck back to my dealer 3 times for this. They refuse to even look at it anymore, even though 3 techs and the shop foreman acknowledged that my truck had an issue. The 3rd visit which the dealer was forced to see me was a complete waste of my time. As soon as I got there they told me there was nothing they could do and that I would not get satisfaction. They can not fix this issue. I asked GM to buy my truck back and was denied. The reason being "it's a natural characteristic of the vehicle". That's coming from the regional manager. A person who has not even seen my truck. I refuse to accept this. I demanded a solution. The GM lady suggested I try another dealership to see if they can figure it out. They are sending me around in circles. I say those of us with this issue keep fighting them. This is absurd. ALL 2016 do not do this, if they did, they would not be able to sell any of them. It drives like a NYC taxi cab with 450,000 miles on it

Loupls · July 21, 2016

I had the shims done.....I still vibrate like a mother f'er at red lights or in traffic....it's horrible. I have a case open with GM about this. I have taken my truck back to my dealer 3 times for this. They refuse to even look at it anymore, even though 3 techs and the shop foreman acknowledged that my truck had an issue. The 3rd visit which the dealer was forced to see me was a complete waste of my time. As soon as I got there they told me there was nothing they could do and that I would not get satisfaction. They can not fix this issue. I asked GM to buy my truck back and was denied. The reason being "it's a natural characteristic of the vehicle". That's coming from the regional manager. A person who has not even seen my truck. I refuse to accept this. I demanded a solution. The GM lady suggested I try another dealership to see if they can figure it out. They are sending me around in circles. I say those of us with this issue keep fighting them. This is absurd. ALL 2016 do not do this, if they did, they would not be able to sell any of them. It drives like a NYC taxi cab with 450,000 miles on it

No they don't I have driven two other 2016 one the same model as mine and an up country neither feel like they are dying when you are at idle in drive.I know this will be a huge pain for me because the dealer I bought it from has a business relationship with the company I work for, but I not getting stuck with a truck that runs like turd at traffic stop what does your vin # start with a 3 read that those are built in Mexico. Mine start with a 3?

dbt1127 · July 21, 2016

No they don't I have driven two other 2016 one the same model as mine and an up country neither feel like they are dying when you are at idle in drive.I know this will be a huge pain for me because the dealer I bought it from has a business relationship with the company I work for, but I not getting stuck with a truck that runs like turd at traffic stop what does your vin # start with a 3 read that those are built in Mexico. Mine start with a 3?

yup, it's 3...I believe all crew cabs are made in MX....

Worst part is I traded my 2014 double cab that had 0 problems in for this hunk of junk

Loupls · July 21, 2016

I have 2004 Z71 that runs better that with a 160000 miles on it

Loupls · July 21, 2016

My next calls are going to be Ohio's attorney general and lawyer I am not playing around I don't care how big GM is this maybe a class action before its over with.