Which parts fail
Components named in complaints (fuel pump, injectors, fuel tank, hybrid and EV propulsion).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2015 Kia Optima owners, lightly cleaned up (personal details are redacted by NHTSA).
I purchased a kia turbo optima from bob's lamphere's beaverton oregon kia dealership 9 days later I felt the acceleration awkwardly bi wanted to return it or exchange but was told no contract was only within 5 days. I took it to kia dealership for diagnostic 3 times I had it for 9 months the last 6 weeks was the 3rd time until Feb 28th It was totaled by a uninsured motorist memes william benton penny lll Or. Driver lic# 1289466 Of 1633 n.e. 76th portland oregon 97213 he was speeding illegally bypassing on a bridge into on coming traffic which was me he ending totally the back end of my kia. No air bags deployed I had no airbag warning light on I suffer injuries whiplash in my neck shoulder and back to this day Wild willy seemed to have injured his leg to the point of amputation ... Portland police report# 21-54465 which is the report that wild willy gave a false identity. …
The contact owns a 2015 Kia Optima. The contact stated while driving 65 MPH, the vehicle shut off without warning. Due to the failure, the vehicle was towed to a dealer where a diagnostic test was performed. The vehicle was diagnosed with engine failure and the vehicle was repaired by the dealer under Warranty. The contact stated that several months after the repair was performed, the contact noticed a fuel odor coming from the vehicle after a visit to the gas station. The next day upon inspection of the vehicle, the contact's husband discovered a puddle of fuel underneath the vehicle. The dealer was notified of the failure and requested that the vehicle be towed to the dealer for an inspection. Upon investigation, the contact discovered NHTSA Campaign Number: 18V907000 (Fuel System, Gasoline; Engine) which the contact linked to the failure. …
The contact owns a 2015 Kia Optima. The contact stated that while driving 70 MPH, the vehicle inadvertently lost motive power. The contact was able to pull over to the shoulder of the roadway, where the vehicle failed to restart. After a visual inspection, the contact observed an excessive amount of oil leaking from underneath the engine compartment. No warning lights were illuminated. The vehicle was towed to an independent mechanic, who diagnosed a failure with engine failure, observing a hole on the side of the engine block. The vehicle was not repaired. The vehicle was then towed to the dealer however, the diagnosis was not yet confirmed. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 18V907000 (Fuel System, Gasoline, Engine), but the VIN was not included. …
The contact owns a 2015 Kia Optima. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently lost motive power. The contact was able to coast to the shoulder of the roadway, where the vehicle was able to be restarted. However, several days later the failure reoccurred, and the contact heard an abnormal sound coming from the engine compartment, prompting the contact to discontinue driving the vehicle. No warning lights were illuminated. The vehicle was towed to the dealer, who diagnosed a nondescript failure with the engine. The contact was informed that the engine needed to be replaced. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 18V907000 (Fuel System, Gasoline, Engine), but the VIN was not included. …
The contact owns a 2015 Kia Optima. The contact received a recall repair regarding a system upgrade for the knock sensor detection system and experienced the failure since the repair was performed. The vehicle was emitting a fuel odor and had a burning odor as if the vehicle was overheating. The driver's and passenger's side side-view mirrors would close while driving at various speeds. The Push to Start button had to be pressed several times to start the vehicle. The contact had taken the vehicle to the dealer who stated that the fuel odor was due to a hole in the fuel line hose. The passenger's side side-view mirror had been replaced. The failure reoccurred. The contact stated that the failure was related to NHTSA Campaign Number: 18V907000 (Fuel System, Gasoline, Engine) however, the VIN was not included. The manufacturer was made aware of the failure and opened a case. …
The contact owns a 2015 Kia Optima. The contact stated that the check engine and battery warning lights were illuminated. The contact stated that the engine had been replaced two weeks prior to the failure. The vehicle was taken to a local dealer for routine maintenance; however, the cause of the failure could not be determined. In addition, during a battery replacement, there were several unknown warning lights illuminated and smoke was coming from the vents. The vehicle was towed to a local dealer where it was diagnosed that there was an EVAP leak, the canister purge valve had cracked, and the battery needed to be replaced. The vehicle was not repaired. The contact referenced Kia Campaign Number: SC135. The manufacturer was made aware of the failure. The failure mileage was approximately 160,000.
My 2015 KIA optima experienced a catastrophic engine fire while I was driving. There was no warning, I just heard a boom in the engine bay the breaks stopped working and all electrical cut out. As I'm coasting, because I'm unable to stop, flames started to come in through under the dash. I couldn't turn the car off, nor put it in park so the doors stayed locked. The driver window was opened just enough for me to grab the top and break it, allowing me to crawl out. The car coasted itself to the shoulder then blew up (I had a full tank of gas.). All this happened in the manner of 30 to 35 seconds. It's important to note that KIA just replaced the engine 2 months prior to this incident.
The contact owns a 2015 Kia Optima. The contact stated that the engine was previously replaced due to abnormal knocking sound. Additionally, the contact stated while driving 60-65 MPH, there was a strong gasoline odor coming through the A/C vents. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed that the low-pressure fuel hose was leaking and needed to be replaced; however, the part was not available. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 22V093000 (Fuel System, Gasoline). The manufacturer was not notified of the failure. The failure mileage was approximately 142,000.
The contact owns a 2015 Kia Optima. The contact stated that while attempting to start the vehicle or while driving at undisclosed speeds, there was an abnormal fuel odor inside the vehicle after the vehicle was serviced by the dealer. The contact stated that the vehicle received an undisclosed engine repair. The vehicle was not taken to an independent mechanic or the dealer to be diagnosed. The manufacturer was not notified of the failure. The failure mileage was 123,323.
Engine lost power and when restart was attempted, it could torn turn over. Tried restarting 3 times with no success. After this, smoke started coming from the hood. I opened the hood and noticed a small flame at the driver side bottom of the engine compartment. Flame intensified and grew and eventually I extinguished with a fire extinguisher. I had just replaced the starter that same week and replaced some wiring at a local car repair facility.
Fuel System complaints in other Optima years
Frequently asked questions
How common are fuel system problems on the 2015 Kia Optima?
NHTSA has 56 complaints about the fuel & propulsion system of the 2015 Kia Optima, 6% of the model year's 1,009 complaints. The component named most often is storage › evaporative emissions › canister (1 mentions).
Is there a recall for 2015 Kia Optima fuel system problems?
No. NHTSA lists no fuel & propulsion system recall for the 2015 Kia Optima, though it has 4 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2015 Kia Optima fuel system problems start?
Half of the complaints with a recorded mileage happened before about 108,000 miles, and 10% before 25,000 miles.
Is it dangerous?
Owners linked 4 crashes, 8 fires and 5 injuries to fuel & propulsion system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.