Rough idle.

[Jeremy76]

I have a 2012 Equinox that has developed an issue. Upon startup, it will do its usual higher idle, then come down to normal idle where it will start bucking, and either die completely, or come out if it. 90% of the time it dies. After starting it back up, it will run fine.

While the vehicle has sat for the last 2 years, basically because of this issue, plus the amount of money spent to keep it in the road.

It has had an O2 sensor, multiple vvt solenoids, plugs, exhaust manifold, high speed fuel pump, the timing chain done twice since we’ve owned it, but believe to have been replaced one other time, and has the breathable oil cap.


If this is an easy fix, we’ll keep it for a spare car, if it isn’t, it’s going bye-bye. I’m tired of spending money on it.

Has anyone else had this issue, or know of a solution to it?

Thanks in advance for any helpful info.

 

[Hey Vern!]

I wonder if it is the cold start valve. Before starting, turn the key on for 15 seconds then off, then start like normal. See if that eliminates the issue.

 

[Jeremy76]

I’ve never heard of the cold start valve. I will try starting it like that though, thanks.

 

[2025 Red Equinox]

I have a 2012 Equinox that has developed an issue. Upon startup, it will do its usual higher idle, then come down to normal idle where it will start bucking, and either die completely, or come out if it. 90% of the time it dies. After starting it back up, it will run fine.

While the vehicle has sat for the last 2 years, basically because of this issue, plus the amount of money spent to keep it in the road.

It has had an O2 sensor, multiple vvt solenoids, plugs, exhaust manifold, high speed fuel pump, the timing chain done twice since we’ve owned it, but believe to have been replaced one other time, and has the breathable oil cap.


If this is an easy fix, we’ll keep it for a spare car, if it isn’t, it’s going bye-bye. I’m tired of spending money on it.

Has anyone else had this issue, or know of a solution to it?

Thanks in advance for any helpful info.

If the vehicle [has sat for a long time, I’d bet bad gas and clogged fuel injectors are suspect.

You may want to also inspect (and clean if needed) the inside of the throttle body bore.

 

[Hey Vern!]

or maybe an intake leak:

 

[Jeremy76]

If the vehicle [has sat for a long time, I’d bet bad gas and clogged fuel injectors are suspect.

You may want to also inspect (and clean if needed) the inside of the throttle body bore.

It was doing this when we were still driving it.

I’ll try cleaning it.

 

[2025 Red Equinox]

It was doing this when we were still driving it.

I’ll try cleaning it.

If you clean the inside of the throttle body bore with spray cleaner, and do not remove it, do not use your finger to move the butterfly valve on the inside of the bore. That can damage the electronic gear control.