I have a 2016 Chevrolet Sonic 1.8L with vin code G automatic sedan. 82,000 miles
When car has not ran in a few hours(motor is “cold”) coasting down hill my car at speeds under 40 the car will surge between 900 and 1400 rpms.
I was having a skip when under load in conjunction with this surging when cold. I replaced coil pack and plugs. This alleviated the skip but I am still left with the surging.
No codes, no lights, and I’ve searched the internet and haven’t found anything. Any suggestions other than throwing away my bowtied Daewoo?
I would check for vacuum leaks. You may have a rubber hose or plastic piece that is leaking air which will cause surging.
Check for vacuum leaks, it could be because of the fuel management system. It could be running lean. Check the simple stuff like checking vacuum leaks or MAF sensers, and have a mechanic check it out.
