2015 Kia Optima: sudden loss of power

Filed Jun 23, 2026 · Engine · OK

While driving my 2015 Kia Optima, the engine failed completely without warning. The vehicle lost power while in motion approximately 300 miles away from my home. All warning lights illuminated and the car shut down during driving conditions, creating a serious safety hazard. The vehicle was towed to a Kia dealership where it was inspected. I was informed the engine has failed and may be related to the known 2.4L engine defect and prior recall campaign involving this engine type. This vehicle has a history of multiple recalls, including engine-related recalls issued in 2018 for the same engine family. The failure occurred suddenly and without prior adequate warning, and the vehicle is now inoperable. I purchased the vehicle in May 2023, and at the time of failure it had approximately 133,000 miles. The engine began knocking loudly prior to failure, then stalled and shut off completely while driving. This incident placed me and others at risk because the vehicle lost propulsion while in traffic. I believe this may be related to a known manufacturing defect in Kia 2.4L engines that has been the subject of recall and/or investigation. I am requesting that this complaint be documented as a safety-related engine failure potentially associated with the existing recall and that it be reviewed for further investigation and manufacturer accountability

Filed Jun 22, 2026 · Electrical, Engine · CA

1. What component or system failed or malfunctioned, and is it available for inspection upon request? The primary failure involved the engine. The vehicle experienced a major engine failure that resulted in an engine replacement under a manufacturer recall. After the replacement engine was installed, the vehicle later developed additional engine-related problems. An independent mechanic advised that the vehicle would require another engine replacement or extensive engine repairs. Additional defects included a malfunctioning moonroof that would no longer close properly and other mechanical issues affecting the vehicle's operation. The vehicle may be available for inspection depending on its current status and location. 2. How was your safety or the safety of others put at risk? The repeated engine problems created concerns about the reliability and safe operation of the vehicle. Sudden engine failure while driving resulted in loss of power, inability to maintain speed in traffic, and being stranded in unsafe conditions. The ongoing mechanical failures caused significant concern regarding the vehicle's dependability and safety. 3. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. The original engine issue was confirmed by authorized service personnel and resulted in an engine replacement under a manufacturer recall. The subsequent engine-related problem was evaluated by an independent mechanic, who advised that the vehicle required another engine replacement or significant repairs. 4. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives, or others? The vehicle was inspected in connection with the original engine recall and replacement. It was also inspected by an independent mechanic regarding the subsequent engine issues. At this time, I am not aware of any inspection by police or insurance representatives related to these mechanical failures. 5. yes, right away

Filed Feb 22, 2026 · Engine · CA

Engine failure while driving on freeway. Almost hit by semi truck. Towed to Dealership. Engine check light flashing complete loss of power. Kia refusing engine replacement under settlement.

Filed Feb 13, 2026 · Engine, Transmission · CA

On December 27, 2025, at approximately 150,556 miles, my 2015 Kia Optima Hybrid experienced sudden engine knocking, power loss, and failure while driving at 65 mph on a highway. The vehicle dropped into limp mode and I had to pull off the highway. The car required towing to the dealership as it would not drive safely. Diagnostics revealed a knock sensor error (P1326 code) and failing connecting rod bearings via Bearing Clearance Test, consistent with the known Theta II engine defect (manufacturing debris causing oil starvation and premature bearing wear). This follows earlier symptoms: Intermittent 'Check Hybrid System' warnings in early December 2025 at 148,665 miles (dealership unable to reproduce, but historical codes noted). The Knock Sensor Detection System (KSDS) software update was performed in February 2022 during prior CHS warnings. Despite onset of issues under the 150,000-mile extended warranty limit per the Kia E2 Settlement, Kia denied coverage due to the minor mileage overage and directed me in a loop between Consumer Assistance and the Settlement Administrator. The defect poses a serious safety risk: potential for sudden engine seizure, stalling while driving, or engine compartment fire (as seen in related Theta II recalls and thousands of the federal safety agency complaints). No crash, injury, or fire occurred in my case, but the failure left the vehicle undrivable and unsafe on the road. I have service records and diagnostic reports to support this.

Filed Sep 26, 2025 · Engine · ID

The engine in my 2015 Kia Optima Hybrid failed due to a known defect with the 2.4L engine used in Kia and Hyundai vehicles. The vehicle suddenly quit running and has been inoperable since. Prior to failure, the car had exhibited knocking noises and loss of power. This placed my safety at risk as the vehicle stalled unexpectedly and could have caused an accident if it occurred in traffic. The failure has been confirmed by an independent mechanic, who diagnosed the engine as needing complete replacement. Kia has refused to cover the repair, stating that the vehicle is past the extended warranty mileage, even though the issue is consistent with widely reported manufacturing defects on this engine family. The engine is still available for inspection, and there were no warning lights before the sudden failure. This problem has been widely reported by other Kia owners but my vehicle’s VIN is not included in the current recall campaign, leaving me with a non-functional vehicle despite the same defect.

Filed Sep 17, 2025 · Electrical, Steering · NJ

Lost power while in the middle of a turn while driving happened intermittently power steering and traction control lights come up on dashboard.

Filed Sep 3, 2025 · Engine · TX

The component that failed was the engine of my Kia vehicle. The vehicle was purchased in 2020. In Q4 2022, I received a recall notice by mail regarding the engine. I immediately took the vehicle to Kia of McKinney, TX, and requested that the recall repair be performed. I was informed at that time that the engine could not be replaced until it actually failed. This forced me to continue driving a defective vehicle for several years. The engine ultimately failed in the second week of June 2025, when the car would not start. It was towed to Southwest Kia in Texas, where it remains available for inspection. My safety and the safety of others were put at risk because I was instructed to continue driving a vehicle with a known defective engine. Kia’s refusal to remedy the recall in advance increased the risk of sudden stalling, engine seizure, or loss of power while driving — all of which pose serious hazards on the roadway. The problem has been confirmed by Kia’s own service centers. Southwest Kia acknowledged the engine failure but denied coverage, citing a supposed “gap” in maintenance records. However, Kia never informed me that there were specific maintenance requirements tied to recall eligibility, and I was never given a clear diagnosis of if the failure aligned with that of the recall. Kia corporate has denied responsibility for replacing the engine despite the active recall. There were no warning lamps or messages prior to the engine failure. The car simply failed to start in June 2025. At no earlier point was I warned that the vehicle was unsafe to drive, nor was I given any proactive remedy other than waiting for failure. I am requesting that Kia be compelled to honor the recall and replace the engine, as their refusal has left me with a significant financial loss and ongoing safety concerns.

Filed Jul 31, 2025 · Engine · TX

Driving towards town on freeway car suddenly die at high rate of speed and lost power at the wheel had to sway to side of road opened up hood of the car and smoke came out had recker pick me up and drove it to the house and started to find the issue and the starter module burn up . the gas line was near started . replace starter and now the car doesn’t crank so is used wrench to trunk motor and now more seized up remove spark plugs and tried manually turn motor nothing lookup recalls on the matter and it said it was recall on the main bearing of the car are premature and Kia won’t honor the recall due to no oil change records I have all items bought and tow truck expense

Filed Jul 30, 2025 · Engine · IL

While driving my 2015 Kia Optima, the engine suddenly failed without warning. I noticed a loss of power, and shortly after, the oil pressure warning light illuminated. Upon pulling over safely, I discovered that the engine had drained all of its oil, despite recent maintenance. There were no prior warning signs or leaks visible. This posed a serious safety risk as the failure occurred in the midst of traffic. The vehicle had approximately 75,885 miles at the time. A mechanic later confirmed catastrophic engine failure due to oil starvation. This issue appears to be consistent with known engine defects in similar Kia models.

Filed Jun 18, 2025 · Engine · 130,000 miles · NY

The contact owns a 2015 Kia Optima. The contact stated while driving 60 MPH, there was a loud clunking sound coming from the engine before the vehicle lost power. The contact exited the vehicle and pushed the vehicle to the right side of the roadway while awaiting Roadside Assistance. No warning light was illuminated. An independent mechanic was contacted. The vehicle was towed to the independent mechanic to be diagnosed, and the contact was informed that the engine had seized and needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure but offered no assistance. The contact was referred to the federal safety agency Hotline to report the failure. The approximate failure mileage was 130,000.

Filed May 20, 2025 · Engine, Transmission · CA

Vehicle experienced sudden loss of power while driving when cylinder 3 completely failed (0 PSI compression). Metal particles found in oil and excessive oil consumption (1 pint/100 miles). KIA dealer diagnosed as piston rings but ignored metal in oil that suggests bearing failure covered under recall campaign. Refused proper diagnostic testing. Vehicle now unsafe to drive with failed cylinder that could cause complete engine seizure while driving. Kia had all recommended services and oil changes since acquired in 11/2016. These service records demonstrate the progression of my vehicle's engine issues, from early oil consumption problems documented by York Auto Care in July 2023 (3 quarts low) to complete cylinder 3 failure with zero compression confirmed by Kia's own diagnostic testing in May 2025. Despite this documented history and Kia's own test results showing catastrophic engine failure, they have denied warranty coverage under their engine campaign that specifically covers bearing-related failures on my 2015 Kia Optima 2.4L.

Filed Feb 17, 2025 · Engine · OH · fire

My wife driving the 2015 Kia Forte on [XXX] on [XXX] Mile Marker [XXX] North bound at 60mph and vehicle lost all power and caught on fire. The vehicle coasted to the side of the road. Police and fire were called and extinguished the flames. There were no accidents or no injuries. I attempted to get KIA to resolve the case as the Theta Engine is known for this issue. Kia refused all claims under Kia Customer Care Case number [XXX]. Kia of Dayton Car dealership reported an engine connecting rod broke and ejected out the side of the engine allowing engine oil to hit the exhaust manifold starting the fire. This is know Safety Issues with this Engine Series that Kia refuses to honor past Law Suit Settlement. I have the Police report, Fire Dept. Report, and Estimate for repair. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)