2021 Kia K5 engine problems
28 owner complaints filed with NHTSA name the engine on the 2021 Kia K5 — 18% of all complaints for this model year.
What owners report
“The contact owns a 2021 Kia K5. The contact stated that while driving approximately 55 MPH, the fuel gauge suddenly went from one-half tank to empty. The fuel level displayed 120 miles to empty. The contact attempted to refuel the vehicle but was unable to add fuel to the tank. The contact also…”
filed Jul 23, 2026
“The contact owns a 2021 Kia K5. The contact stated that there were failures with the spark plugs. While driving at an undisclosed speed, the vehicle shuddered, and the engine sputtered. The contact stated that fuel spewed out of the filler neck while refueling the vehicle, and the fuel gauge…”
filed Jul 22, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Engine problems in other K5 years
| Year | Reports | Share |
|---|---|---|
| 2025 K5 | 3 | 6% |
| 2024 K5 | 8 | 30% |
| 2023 K5 | 12 | 12% |
| 2022 K5 | 25 | 20% |
Other reported problem areas on the 2021 Kia K5
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.