2018 Hyundai Sonata engine problems
206 owner complaints filed with NHTSA name the engine on the 2018 Hyundai Sonata — 56% of all complaints for this model year.
What owners report
“The lower aluminum engine oil pan developed a structural hairline fracture ("micro-crack") directly along the factory casting ridge adjacent to the drain plug. The component failed without any external impact, road hazard, scraping, or underbody damage. The failure was officially confirmed and…”
filed Jul 20, 2026
“I purchased my vehical at Car Culture in Warren, Oh. The dealer said to only take it there for maintenance, so I did as required. Whenever the check engine light came on I would bring it there and they would say it was a sensor and they fixed it. And one day it started miss firing and the light…”
filed Jul 6, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related service bulletins
Certain Santa Fe (TMA), Santa Fe Sport (AN), Sonata (LFA), and Tucson (TL) vehicles equipped with Theta II engines may exhibit elevated engine-out emissions. The California Air Resources Board has determined that these…
26-01-013H-2 DN · Service Campaign · issued May 21, 2026Certain 2019 – 2020 model year Santa Fe, 2017 – 2018 model year Santa Fe Sport, 2015 – 2019 model year Sonata, and 2018 – 2021 model year Tucson vehicles may exhibit elevated engine-out emissions. Hyundai is conducting…
9C2 OL · Service Campaign · issued Apr 14, 2026
Engine problems in other Sonata years
| Year | Reports | Share |
|---|---|---|
| 2024 Sonata | 3 | 7% |
| 2023 Sonata | 26 | 31% |
| 2022 Sonata | 24 | 26% |
| 2021 Sonata | 34 | 27% |
| 2020 Sonata | 30 | 18% |
| 2019 Sonata | 83 | 53% |
| 2017 Sonata | 382 | 50% |
| 2016 Sonata | 444 | 62% |
| 2015 Sonata | 614 | 54% |
| 2014 Sonata | 299 | 40% |
| 2013 Sonata | 728 | 38% |
| 2012 Sonata | 567 | 36% |
Other reported problem areas on the 2018 Hyundai Sonata
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.