2012 Kia Optima Showing Troubling Signs: Jerking during Acceleration, Black Exhaust Smoke, Unsteady Engine, and Starting Issues

Hey there I totally understand how frustrating an unreliable ride can be. I had a similar issue with my 2009 Kia Sorento a while back. It wasn't exactly the same, but I also started facing rough idle and unusual stalling, coupled with a strange shaking sensation. Turned out, it was indeed the idle control valve. My mechanic found a faulty cable/plug on it. While it was a bit of a surprise, the fix was basically to replace the idle control valve and the associated cable/plug. And you know, it's not a small issue. A defective Idle control valve can cause all sorts of strange behaviour, and it was affecting the overall engine performance for me. It’s an essential part of the engine management system and honestly, a faulty one can lead to a pretty rough driving experience. I'd definitely suggest getting it checked out. It's always better to be safe than sorry, considering it can be a nuisance more than anything else. Hope this helps!

Hey there, Appreciate the response! It's reassuring to know someone else out there has faced something similar. I guess I'll have to bite the bullet and find a trustworthy mechanic to get my Optima fixed after all. Out of curiosity, do you remember how much that fix set you back? And have you had any other related issues crop up since you got it sorted? You know, just asking so I can get a rough idea on what I might be dropping and know what to possibly expect in the future. Thanks again for the help!

Hey! No worries, glad to help out a fellow car enthusiast. When I got the idle control fixed for my Sorento, it cost around 155.00 €. That was specifically for setting right the defective cable/plug on the idle control valve. Since that repair, the idle control has been smooth sailing, no quirks whatsoever. It was definitely worth the fix, the difference in ride quality was night and day. Just bear in mind every car and situation can be different, so costs may vary. But it surely provides a ballpark. Here's hoping your Optima gets back to her glory days soon! All the best!

That's good to hear and definitely something I was hoping to know! Paying around that ballpark doesn't sound too harsh for a much smoother ride. Looks like getting the idle control checked will have to be my first step, fingers crossed. Thank you for putting my mind at peace and for your kind words. Helpful insights from like you make situations like these less daunting. You've been a great help! Will update on the situation once I've gotten it sorted. Catch you later!