2018 Kia Optima — dealer cannot reproduce an intermittent warning

Start with the test that can prove you wrong. Capture voltage while the 2018 Kia Optima is actually failing — after it restarts you've lost the clue. You'll know quickly if you're on the wrong tree. Not gospel, but it saved me a headache. Not interested in a five-hour wait for a shrug.

If it were in my driveway, move a coil or plug on the 2018 Kia Optima if it's cylinder-specific and see whether the code follows. Don't erase codes until someone who can help has seen them. This is from a 2018 Kia Optima in Seattle with 126,000 miles. Not gospel, but it saved me a headache. Video is ugly but it shows the hesitation.

If it were in my driveway, get a real battery/charging test on the 2018 Kia Optima, not just resting voltage, before blaming a module. You'll know quickly if you're on the wrong tree. I'd want that in writing, not as a promise. I'd sleep better after that step, even if it finds nothing. I keep a notes app thread for this now.

Ask what changed right before it started. Capture voltage while the 2018 Kia Optima is actually failing — after it restarts you've lost the clue. You'll know quickly if you're on the wrong tree. Learned this the expensive way on a previous car. Parking it somewhere I can hear it better next time.

Intermittent stuff lies if you only catch it once. Move a coil or plug on the 2018 Kia Optima if it's cylinder-specific and see whether the code follows. That's the branch I'd chase this week. On “dealer cannot reproduce an intermittent warning,” that was the fork that mattered for me. Take it or leave it — that's what I'd do. If it repeats twice more I'll book time.

Ask what changed right before it started. Two 2018 Kia Optimas can feel identical and have different causes, so measure before you copy someone else's repair. Save the big job until that test fails. Write the result down so the next test isn't a repeat of the last one. If this is nothing, great. I want that in data.

I wouldn't throw parts yet. Loaded-suspension checks on the 2018 Kia Optima catch play that a wheels-hanging inspection misses. Save the big job until that test fails. This is from a 2018 Kia Optima in Seattle with 126,000 miles. Run the total, not the monthly, before you commit. I'll update if anything new shows up.

OP update: scanned the 2018 Kia Optima again and still only have the one pending code, no new lights. Heat soak after errands is the other window.

I wouldn't throw parts yet. Loaded-suspension checks on the 2018 Kia Optima catch play that a wheels-hanging inspection misses. You'll know quickly if you're on the wrong tree. Time, temperature, and whether it's in gear are the notes that actually help a shop. If the story changes I'll post the new data.

I went back under the 2018 Kia Optima and it only happens after a heat soak, not on a cold start. Trying not to diagnose from the couch.

Checked the easy stuff on the 2018 Kia Optima and found one clue worth chasing before I book a shop. I keep a notes app thread for this now.