2018 Kia Optima problems and complaints
Owners have filed 233 complaints with NHTSA about the 2018 Kia Optima. The most-reported areas: Engine (132), Unknown Or Other (38), Electrical System (33).
Key takeaways
- 233 owner complaints on file with NHTSA.
- 10 involve a crash, 10 a fire, 9 reported injuries.
- Complaints are unverified owner reports; recalls are confirmed defects.
| Component | Complaints | Share |
|---|---|---|
| Engine | 132 | 57% |
| Unknown Or Other | 38 | 16% |
| Electrical System | 33 | 14% |
| Power Train | 19 | 8% |
| Service Brakes | 17 | 7% |
| Engine And Engine Cooling | 14 | 6% |
| Exterior Lighting | 14 | 6% |
| Fuel/Propulsion System | 13 | 6% |
| Steering | 12 | 5% |
| Vehicle Speed Control | 10 | 4% |
| Air Bags | 9 | 4% |
| Structure | 7 | 3% |
One complaint can name several components, so shares add up to more than 100%.
Parts for the 2018 Kia Optima
GarageDex's verified specs for this car. Each Buy button searches Amazon for that exact part.
- Battery
- Engine oil
- Oil filter
- Engine air filter
- Cabin air filter
- Wiper blades
- Headlight bulb
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| Version | Overall | Front | Side | Rollover |
|---|---|---|---|---|
| 2018 Kia Optima 4 DR FWD | 5/5 | 5/5 | 5/5 | 5/5 |
Latest complaints, as filed
Owner-written and unverified by NHTSA.
Power Train,unknown Or Other,engine - filed 2026-10-21
My 2018 Kia Optima has the Theta II 2.4L engine. In February 2026, the dealer performed an engine/powertrain computer reprogramming. In August 2026, the engine failed and the vehicle was taken to an authorized Kia dealer, where the engine was replaced under the Theta II engine warranty. The vehicle was at the dealer fr...
Engine - filed 2026-09-08
The contact owns a 2018 Kia Optima. The contact stated that upon starting the vehicle, the vehicle jerked abnormally. The failure persisted while driving, and the vehicle lost motive power. The contact was able to restart the vehicle; however, the failure persisted while driving. The vehicle was towed to a dealer to be...
Engine - filed 2026-08-20
The contact owns a 2018 Kia Optima. The contact stated that while driving at an undisclosed speed, the vehicle failed to accelerate and failed to exceed 52 MPH. The vehicle shut off. The contact stated that the engine was running rough while stationary and the vehicle shut off without warning. The vehicle was taken to ...
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More for the 2018 Kia Optima
Complaints are reports filed by owners with the National Highway Traffic Safety Administration. NHTSA publishes them without verifying them, and counts rise with how many cars were sold, so compare years of the same model rather than different models. Crash ratings are NHTSA's own 5-Star Safety Ratings results.