2015 Kia Optima fuel/propulsion system problems

“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.”

“This is a formal vehicle safety complaint regarding a manufacturer's active refusal to remedy a known safety defect under an active recall campaign guidelines.My 2015 Kia Optima Turbo experienced an active internal mechanical engine knock, violent sputtering, and a complete engine seizure. The vehicle is currently sitting un-driveable at an authorized Kia dealership.The required Knock Sensor Detection System (KSDS) software update was successfully completed on this vehicle prior to the incident, legally qualifying it for a 100% free long-block engine replacement under the manufacturer's active Lifetime Warranty extension. However, the dealership service department is actively withholding the safety warranty paperwork and refusing to submit the diagnostic photos and engine seizure data to corporate for warranty approval unless I agree to pay an additional $800 out of pocket for an external throttle body and O2 sensor.I have explicitly declined the retail accessory charges five separate times. I only authorize the replacement of my front sway bar links. Instead of separating the ticket and processing the free engine block safety remedy, the dealer is holding my…”

“12-01-2025 driving to work in the morning approx 7:00A.M. and turned on the heater and had a very strong smell like fuel so immediately turned it off. Cracked my windows to air it out and then was super cold again and had turned on the heater to try again. Immediately had to turn it off and rolled windows down to air it out because the smell was intense and had started to feel nauseas. Later in the day, about to head to lunch and had started the vehicle and smelt a lot like gas and turned it off and had someone come out to double check the smell. Co worker had strong smell from the hood area and looked underneath the car and can see a little drop puddle. Opened the hood and lifted the cover to engine where you can see the leakage coming from the center hose and spill puddle. Service tech came to take a look and advised its the fuel feed to the high pressure pump. This is a safety concern because fuel is extremely flammable and can put myself in dangerous situation of firing igniting in the car or hurt others around. No check engine light and prior the vehicle incident car has been consuming oil putting in about 1- quart a week or so with commute miles about 270 weekly.”

“While driving my 2015 Kia Optima (VIN: [XXX] ) at highway speed, the engine suddenly shut off without any warning lights, alerts, noises, or check-engine indicators. This created a dangerous situation for me and surrounding drivers. The vehicle had passed state inspection only 3 months earlier with no issues. The sudden shutdown is consistent with the known Theta II engine defect investigated by NHTSA. The car is now completely undrivable. Two Kia dealerships refused to assist, claiming that they cannot perform KSDS because the engine is already dead. These reasons directly contradict the Kia Theta II engine settlement terms. This sudden stall is a safety hazard and could have caused a severe crash. I am requesting that NHTSA review this incident as a potential recurrence of the engine-stall defect already documented in Hyundai/Kia vehicles.”

“While driving my 2015 Kia optima I was getting ready to turn in to my residence.My car completely shut off but my lights had got dimmed.So I had it towed to the Kia dealership then proceeded to tell me it has three recalls on it.Then a customer service representative said that I would have to pay $200,and something dollars to have my car diagnostic done.Whoever I replied even with these recalls I have to pay for diagnostic test to be done she replies yes,but I’m thinking they are just trying to make money off customers.”

“My 2015 Kia Optima Hybrid poses a serious safety risk. While driving at highway speeds, the car has randomly shut off multiple times. A "Check Hybrid System" or hybrid battery warning appears on the dashboard, and the vehicle either loses power entirely or switches to electric-only mode and coasts to a stop. This happens without warning, putting my life and the lives of others at risk. I already had the relevant hybrid system recall work completed by a Kia dealer, but the issue persists and the car remains unreliable and unsafe. This appears to be a known issue affecting many 2011–2016 Optima Hybrid vehicles. Kia needs to be held accountable for continuing hybrid system failures that occur post-recall and outside of warranty. This is a dangerous, recurring defect.”