Idles rough while stopped

[tommylama]

Sometimes I'll be stopped and my engine will start to idle rough (kind of like a bucking horse). It's only happened two or three times since I got my car in late May but still makes me wonder if there's something wrong.

2013 RS Auto.

 

[qwed94]

Well I cant answer for the turbo. but my 1.8 does that once in a while too. Every OBDII vehicle I ever had, has done that on occasion. Could be a little water/dirt in the gas. Could be the sudden changes in air pressure from going to stop. Could be a few things. Unless it starts idling rough "most" of the time. I wouldnt think about ever again.

 

[CjCsonic]

Mine will do that once in a while too. It's usually when I pull out onto the street and give her a little gas to merge, maybe it's the computer adjusting after startup?

 

[SONIC1.4]

Mine has always been that way

 

[tommylama]

Anyone know why it does this?


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[Chevrolet Customer Care]

Sometimes I'll be stopped and my engine will start to idle rough (kind of like a bucking horse). It's only happened two or three times since I got my car in late May but still makes me wonder if there's something wrong.

2013 RS Auto.

Hi tommylama,

I'm sorry to hear about this issue. I'm here to help, and would like to look further into this for you. Can you please private message me your VIN and mileage? I'm looking forward to hearing from you soon.

Patsy G
Chevrolet Customer Care

 

[Larrymer]

Give some more detail. Car is already warmed up? Stock or modded?

 

[tommylama]

Completely stock. Car should be warmed up by then. It normally does it within the first 10 minutes of me driving it, but I always start my car 5 to 10 minutes before I leave.


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[vicktorias]

Rough Idle

I have a 2013 Sonic that does the same. It was quiet starting when I first bought it. You could hardly tell if it was running. Now it idles so rough it shakes the whole car. The fan clicks loud also when it turns on.

 

[Larrymer]

No check engine or service lights? If you have access to a scan tool I'd see if anything is stored in history. Autozone may be able to tell you this for free.

 

[tommylama]

No lights. I'll stop by autozone to see what I can find out.


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[lattyd]

I had a rough-ish idle that got worse as winter blend gas started to propagate the pumps..... cleared almost all of it up by checking my plugs.

As many have found, they are frequently out of spec from the factory

I set mine to .028 for reference (1.4T)

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[Blue hedgehog]

Auto or manual? I read a thread, can't find it now but there is an issue with the autos not going into neutral when stopped. I believe the repair is to rebuild the trans and replace the clutches. My car is developing this issue. When it acts up, I throw it in neutral and it goes away. I have to bring it in and have it checked. Just need time to do it.

 

[tommylama]

Auto.


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[Blue hedgehog]

Try putting it in neutral when it acts up. If it goes away that's the problem. I don't feel any vibration when it automatically goes into neutral. When it doesn't I put it in neutral and all vibration goes away.

 

[Luv2xlr8]

I get that rough idle once in a while as well when I come to a stop. This only happens when the car is in "open loop". I've been searching on google but I keep getting different answers.

If you have an ultra gauge, check on the top right hand corner and you will see the ring. If your car idles rough, check to see if the ring has a open and that will indicate you are in open loop.

Edit: here I found this, i get the same symptoms except I don't have any codes. So it might seem I have a vacuum leak somewhere.
http://www.iatn.net/forums/13/42000/seeing-the-whole-picture-the-importance-of-loop-status

 

[Sonicnw]

okay guys, gals, your little engine is a 1.4 or 1.8... when you have your defrost on it uses the A//C to help defrost your car.. Likewise if you have your A/C on when its hot out the A/C runs. This is putting a load on the engine at IDLE. As soon as you apply the accelerator the engine is able to overcome the strain of the A/C at idle and you no longer feel it. Try this again with your cars with NO A/C or DEFROST on and see if it still does it. Also at idle with none of these on, do turn them on and you will feel the load on the engine that I am speaking of. Good luck, this is normal for small engines. you don't notice it in v-8 engines as they have the power and inertia of the bigger engine and rotating mass to overcome this issue at idle.

 

[Luv2xlr8]

Yes I know about the extra load when defrost is on. This happens without the defrost on, I should note that my car has the 1.8 though.

 

[SSTODD]

It may be the auto trans dis-engaging when you are stopped, it feels like lugging or surging sometimes when releasing the brake.

 

[Chevrolet Customer Care]

I have a 2013 Sonic that does the same. It was quiet starting when I first bought it. You could hardly tell if it was running. Now it idles so rough it shakes the whole car. The fan clicks loud also when it turns on.

Hey There,

I'm sorry to hear that you are experiencing problems with your Sonic. Please let us know if you would like for us to take a further look into your concern. We are just a PM away! We look forward to your reply.

Kristen A.
Chevrolet Customer Care