Inconsistent Idling after Battery Replacement?

2011 KIA OPTIMA

115,000 MILES • AUTOMATIC

JAYFIVS

MEMBER
10 POSTS
FOLLOW

I replaced the battery to my 2011 Kia Optima earlier and upon cranking it back up, it started right up and idled around 750RPMs. Letting it sit for a few minutes, the RPMs bounced between 500-800 in park and my engine would kind of "stop" and "go" causing small shudders and vibration.

Is this normal or is there another issue I should check for?

May 25, 2026 at 10:37 PM

STRAILER

CAR REPAIR CONTRIBUTOR
54,233 POSTS

This is normal as the computer is relearning the engine idle map. I would just drive it and the problem should go away, here is a guide to help you as well.

https://www.2carpros.com/articles/engine-stalls-idles-too-high-low-after-dead-or-replaced-battery/

Let me know how it goes

May 26, 2026 at 4:38 PM

JAYFIVS

MEMBER
10 POSTS

Thanks for the response; but now we have another issue.

Even with a brand new battery, my car drive fine this morning then while idling in a parking lot, my warning lights flickered and flashed on again and after turning the car off, my car didn't start again.

Does this point more towards an alternator issue; or what could be causing my battery to completely drain even after a brand new one was put in last night?

May 26, 2026 at 4:41 PM

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