What 1,000 owners told NHTSA about the 2015 Kia Optima

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.

NHTSA ODI 11719695

Engine seized and won’t turn at all

NHTSA ODI 11719754

Paint is peeling off all over my car. I see this is a known issue with the white paint and nothing is being done about it. I have touched up a few spots but it is only getting worse

NHTSA ODI 11718562

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 NHTSA 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.

NHTSA ODI 11717931

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.

NHTSA ODI 11717265

Valve cover leaking and oil dripping oil on exhaust at 114k miles. Risk of engine fire.

NHTSA ODI 11716870

The contact owns a 2015 Kia Optima. The contact stated that while driving at various speeds, the driver's side and passenger's side doors' exterior trims separated from the vehicle. The dealer was notified of the failure. The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the repair was not covered because the VIN was not included in an unknown related recall. The failure mileage was approximately 120,000.

NHTSA ODI 11715114

The contact owns a 2015 Kia Optima. The contact stated that while driving at an undisclosed speed, the engine seized, and the vehicle stalled. The vehicle was able to coast to the side of the road. The check engine warning light and several other warning lights were illuminated. The contact raised the hood, and there was a burning odor coming from the engine. The vehicle was towed to the place of employment. A mobile mechanic arrived at the place of employment and used a handheld code reader to diagnose the vehicle, but no DTC was retrieved, and no cause for the failure was determined. The starter was replaced; however, the vehicle failed to restart. The vehicle was towed to an independent mechanic, who diagnosed that the engine had failed and needed to be replaced. The vehicle was not repaired due to the cost. The contact stated that the vehicle was purchased six months prior to the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 96,000.

NHTSA ODI 11714265

I've had car for not very long and rid bearings now all of a sudden went out and engine is bad at this point and don't understand why my vehicle wouldn't be included in all the different recalls for 2015 optima because it's one of the years of theta 2 engine being recalled and mine says 0 recalls why is that?

NHTSA ODI 11713208

Yesterday, [XXX], My 2015 kia optima engines reved up wothout me pushing the gas & within seconds later a loud noise and metal fell from under the hood. After pulling over, popping the hood on the passenger side and under the engine a fire had started. My daughter was seated in the back passenger side her door had locked, thankfully the passenger door was left opened bc within minutes the entire car was filled with smoke and engulfed in flames. Prior to this the steering wheel would jerk even while at a red light. This car just did have 100,000 miles & no knowledge this prior. Thank god i was able to get my daughter out of this vehicle & this didnt end in a tragedy due to negligence if this was a prior known fact. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11713230

**This complaint isn't directly related to the safety of the car** However, due to outstanding number of similar cases i've witness online. I would like to formally make a complaint for the defective White paint on my Kia vehicle. Like many other "white" Kia and Hyundai vehicles, the white paint is bubbling and peeling from multiple areas of my vehicle all at once. I have always taken care of and hand washed my car, so i know the paint isn't peeling because of user/owner damage. Road debris would also only cause paint damage on the front bumper and/or hood, which doesn't explain the bubbling and peeling happening on all the other parts of my car.

NHTSA ODI 11712126

The contact is calling on behalf of her grandson for a 2015 Kia Optima. The contact stated that while he was driving at approximately 35 MPH, the vehicle was making an abnormal sound and stalled. The contact stated he restarted the vehicle and was able to shift to drive (D), but the vehicle again stalled. The contact stated that he observed that white smoke was coming from under the hood. The contact stated that he pulled over and stopped the vehicle, opened the hood, and saw that smoke and flames had formed under the engine. The contact stated that he called the fire department. The fire was extinguished using foam. The vehicle was towed back to the contact's residence. The contact had not called a dealer or the manufacturer. The vehicle was not diagnosed or repaired. The contact had researched online and related the failure to NHTSA Campaign Number: 21V331000 (Service Brakes, Hydraulic). The contact stated that her grandson had not received a recall letter from the manufacturer. The failure mileage was 158,006.

NHTSA ODI 11712145

I’ve gotten my vehicle fixed four times now thinking it was an electrical issue, not aware of the recall. Did my research this fifth time when my brake lights completely went out and smoke at some point in times come through my air-conditioning. I’ve spent more money trying to fix the vehicle with no idea that there were issues already about it.

NHTSA ODI 11711673

My Kia OptimaLX had no check engine light not running any different no warning or light indicators turned on but car caught on fire while parked after only driving less than 5mins less than 1 mile from home. Entire front dash burned all the way to the gear shift. Every recall notice recieved was taken care of as soon as I was notified that there was a recall and they had the part to change it out. The engine was part of the recall and was replaced and a fuse module box was replaced 1 month or less from the time of the fire. Car is considered a total loss from insurance company.

NHTSA ODI 11709571

Engine seized

NHTSA ODI 11709557

My 2015 Kia Optima has a failing ABS/HECU module consistent with the Kia ABS fire recall. The brake lights stay on constantly even when the brake pedal switch is unplugged. If I unplug the ABS/HECU module, the brake lights immediately turn off, which confirms the ABS module is back-feeding power into the brake light circuit. I also previously experienced the ABS pump running with the vehicle turned off. Currently the ABS, ESC, EPS, and Brake warning lights are illuminated and all stability/ABS functions are disabled. This is a clear safety hazard affecting braking, electrical safety, and vehicle fire risk. I have already been to the Kia dealer twice and they dismissed the issue after only checking the recall fuse. They refused to address the ABS module itself even though the vehicle is unsafe. The recall appears insufficient because the module has now failed. I need Kia to replace the ABS/HECU module under recall safety remedy.

NHTSA ODI 11708255

The car is experiencing the same problem reported on technical service bulletin SA187 (Blind spot detection (BSD) system logic improvement (SA 187)) BUT KIA states my VIN number is not listed under the service bulletin and therefore I have to pay $189 to get a software upgrade done. The "Check BSD system" illuminated in the instrument cluster has been cleared twice by my mechanic and still comes back after a few days. To me this issue should have been made a recall because of its criticality... the BSD system is a core safety feature of cars and reduces accidents substantially. There was no way for me to know my car has this problem unless it is made a recall. I have NOT had any accident related to this issue but i had to pick an incident date to complete this complaint. I have called KIA customer service at 1-800-333-4542 twice to find out whether the VIN number should be included in the service bulletin and the answer was no and whether i should report this to NHTSA with the possibility that certain VIN numbers were left out of the service bulletin in error. No answer as to what to do to investigate this was given by KIA. That's why i'm reporting this on here. The service bulletin has been attached to this complaint. My question to NHTSA is whether certain vehicles were left out of the service bulletin in error and whether the manufacturer is liable for the repair at no cost to the consumer. If NHTSA finds out the manufacturer is liable will you notify them to pay on a case per case basis or will you make this service bulletin a recall? Again this is SAFETY HAZARD that can cause crashes and accidents. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11707481

The contact owned a 2015 Kia Optima. The contact stated that while driving at 55 MPH, while depressing the accelerator pedal, the contact could smell a burning smell within the vehicle, and then he noticed smoke coming from the front of the vehicle. No warning lights illuminated. The contact pulled over to the right side of the road and exited the vehicle, opened the hood, and noticed smoke and flames coming from the engine. The contact exited the vehicle and stood on the side of the road, and called 911. No injuries were sustained. No medical attention was required. The contact mentioned the police showed up on the scene; however, he could not remember if he received a police report. A fire department report was filed. The fire department extinguished the fire. The vehicle was destroyed. The vehicle was towed to Pro-Cars. The vehicle was not repaired. The contact mentioned he contacted his insurance company, and they informed him that the vehicle was a total loss. The manufacturer was notified of the failure, and they transferred him to the escalation department and informed him that an inspector would inspect the vehicle, and he had to wait seven to ten business days for a resolution. The failure mileage was 53,000.

NHTSA ODI 11705972

The engine in my 2015 Kia Optima suddenly seized due to connecting rod bearing failure at approximately 55,000 miles. This vehicle is known to be affected by the Theta II engine defect. I was never aware of the seriousness of the recall software update and did not receive meaningful notice that failure to install it could result in catastrophic engine failure. Kia has denied engine warranty coverage solely because the software update was not installed prior to failure, despite the defect existing regardless of software.

NHTSA ODI 11705421

My 2015 Kia Optima (VIN [XXX] ) experienced sudden engine failure and stalled while driving at approximately 90,000 miles. There was no oil pressure warning light and no knocking prior to failure. The check engine light illuminated shortly before the stall. Kia is denying engine coverage solely because an ECU/KSDS update was not performed. I was never notified of this update because Kia had an incorrect address on file for me. This failure is consistent with known Theta II connecting rod bearing defects that have resulted in recalls and warranty extensions. I believe this is a safety-related defect and am requesting review. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11705206

The contact owns a 2015 Kia Optima. The contact stated that while driving at an undisclosed speed, the engine seized. The contact stated that the check engine warning light was illuminated several minutes before the engine seized. The vehicle was towed to an independent mechanic, where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The vehicle was then towed to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact was informed that the repair was not covered under warranty. The manufacturer was made aware of the failure but provided no assistance. The contact was informed that because the previous owner did not have an unknown software update performed, the repair was not covered under warranty. The failure mileage was approximately 138,000.

NHTSA ODI 11704313

The contact owns a 2015 Kia Optima. The contact stated that while driving at an undisclosed speed, the engine seized. The contact stated that the failure had occurred while driving on the highway. No warning lights were illuminated. The contact used a portable diagnostic machine but failed to retrieve a fault code. The vehicle was towed to an independent mechanic, where it was diagnosed with engine failure. The vehicle was not repaired. The contact was advised to tow the vehicle to the dealer. In addition, the contact was informed of an unknown recall for the year, make, and model vehicle. The vehicle was towed to the dealer, where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. In addition, the contact was informed of an unknown recall; however, the VIN was not under recall. The contact was advised to contact the NHTSA Hotline to report the failure. The manufacturer was made aware of the failure but provided no assistance. The contact was informed that the vehicle was purchased used. In addition, the contact was informed that the recall mileage limit was 100,000. The failure mileage was approximately 99,325.

NHTSA ODI 11704336

In September of 2025, my radio and back up camera stopped working. I contacted Hayward Kia and was informed by staff member, Eraca Craig, that my 2015 Kia Optima needed a software update that was covered by a recall. I waited several weeks for the dealership to contact me once the update was available. During the waiting period my car's battery started to drain intermittently. I had to have the battery recharged multiple times by AAA. The battery would stay charged for a few days, maybe a week, then I'd experience the same issue. AAA towed my car to Kia Hayward on October 3, 2025. They charged my battery and kept my car over night to see if the battery would stay charged, it did not. Eraca told me that the AC Delco battery I purchased on January 16, 2025 was not "compatible" with my car. She recommended a factory Kia battery which I purchased on October 7, 2025. By November 1, my Kia battery had drained. AAA recharged the battery and it held a charge until November 25, 2025. When I took my car to Kia on November 11, 2025 for the software update, I was told that the update did not apply to my malfunctioning radio and camera therefore I needed to replace the entire unit for $4,080.49. On December 6, 2025 I had a diagnosis performed on my car, it reported codes C1102, B1102, B1112, and P000. C1102 indicates an issue with the HECU. My 2015 Kia Optima has had three recalls related to the HECU (#SC284,#SC212, &#SC197). On December 8, 2025 I made a request, via e-mail, to Eraca Craig that my HECU be inspected for leaks and to have the HECU fuse replaced. I understand that these services were recorded as performed in the past, but I need them performed again because I'm not satisfied that Kia has remedied the situation. I've also filed complaints with the Kia Customer Care Center. My case numbers are #25697367 and #25723089.

NHTSA ODI 11703872

The incident took place on Sunday, December 30th. I was driving to pick up my children from their father and on our way home my car stopped accelerating entirely. This had only happen one other time a few days prior. I was in a gas station parking lot and initially when I turned my car on and went to put it into drive it wouldn’t accelerate. I thought that was odd so I did the only thing I knew how to, I checked my oil levels. Levels were full and no other issues were there. The check engine light had popped up when I turned my car back on but my car did accelerate so I thought nothing of it. I took my car to auto zone for a diagnostic and they told me my “B cam shaft” sensor needed to be moved and that could be causing the engine light to come on and ticking in my motor. I called a few shops getting quotes and eventually was forced to tow to the closest shop to me after my car refused to start overall. They replaced the battery and the b cam shaft censors and still were unable to get the car started. They told me 3 recalls were open on my car, including the motor and to have it towed to Kia for a full replacement. After calling Kia to have the repairs done, they refused me service based on a previous owner not handling prior recalls.

NHTSA ODI 11702641

The contact owns a 2015 Kia Optima. The contact stated that while driving at 40 MPH, there was an abnormal knocking sound coming from the engine. No warning light was illuminated. The vehicle was taken to the dealer, where it was diagnosed with engine failure, and the contact was informed that the engine needed to be replaced. The contact stated that the dealer refused to repair the vehicle. The contact was informed that the HECU recall repair needed to be completed first. The contact was unaware that the vehicle was included in NHTSA Campaign Number: 21V331000 (SERVICE BRAKES, HYDRAULIC). The vehicle remained at the dealer unrepaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 77,000.

NHTSA ODI 11702771