2015 Kia Optima Engine

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

The vehicle started making a loud knocking/tapping noise while driving. The vehicle has randomly acted as if it was going to stall while driving prior to the knocking. Instantly the car was brought home and parked. A mechanic has assessed the vehicle and states the noise we are hearing is the rods. We also contacted another mechanic and they advised us to look up the VIN due to a recall for 2015 Kia optima’s and the failure of this exact issue but we learned it was only for hybrid models even though this model has had the same exact issues as that model. I then see there have already been complaints made for my same issue and model yet no recall campaign has been initiated. I am fearful to drive or try to sell this vehicle because what if someone else drives it and it does stall again during driving and injury or death occurs.

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.

Engine seized and won’t turn at all

On Friday, February 27, 2026. This vehicle is being driven and vehicle seized and disabled on the road. In the middle of rush hour, traffic in a dangerous spot, local police had to be called out to assist, as no location was identified for a tow truck to be able to pick it up... The police had to dispatch their own tow service. After being towed from location where a car was disabled, mechanic looked at vehicle identifying there was no oil in the car. However on, September 9, 2025 an oil change was performed on the vehicle at 139,969 the car seized at 143,369.. That is approximately 3,399 miles driven from the time of the oil change up until the time it seized... There was no indicator lights that ever identified that an oil change was needed or low on oil on the vehicle prior to the car disabling..

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.

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?

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.

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.

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)

The contact owns a 2015 Kia Optima. The contact stated while driving 70 MPH, the vehicle lost motive power. There was no warning light illuminated. The contact pulled over, stopped on the shoulder lane, and had the vehicle towed to a local dealer to be diagnosed. The contact was informed that the knock sensor was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 98,000.

See attached document for complaint.

My engine failed in my 2015 Kia Optima. I took it to the Kia dealership in my city, and was advised to provide documentation of oil changes. In which I did, and was told that coverage for the engine recall was denied due to one gap where I went roughly 15,000 miles without an oil change. When asked when this gap was, they stated in 2021, and I asked how can I get documentation of that if I don’t have the receipt from that long ago. They stated that they need documentation to be able to approve the engine to be covered under the recall. it has been advised that Kia would have to prove exceptional neglect, in which one gap from 2021 is not exceptional neglect. I called the Kia. Customer service complaint line and filed a complaint with a case number, and was told that there’s nothing they can do without that documentation from that one gap. In which I asked to escalate this to a manager or supervisor and was told I could not do that. when I called the Kia dealership to see options, all they kept doing was trying to persuade me to just buy a new car asking don’t you just want a new car. I am without a vehicle and I have two kids that I need to help get to and from school doctors appointments as well as after school activities. I do not believe that a one gap should disqualify you from coverage of an engine under the recall.

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.

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.

I experienced a sudden engine failure on the highway due to the known Theta II engine defect. The engine completely shut down in the middle of traffic, nearly causing a serious accident. I never received any notice from Kia regarding the KSDS (Knock Sensor Detection System) update or any engine recall programs. When I contacted Kia Consumer Affairs, they told me they would not cover the engine replacement because the KSDS update was not installed prior to the failure. Kia admitted that the notice was sent to the previous owner, not to me, even though I am the current registered owner of the vehicle. I was never given the opportunity to install the software update or address the defect before this dangerous failure occurred. Kia representatives also stated that KSDS “was not a recall, only part of a class action lawsuit,” and therefore they are not obligated to cover the engine. This is misleading. The underlying Theta II engine defect was subject to NHTSA investigations and multiple recall campaigns. The sudden engine shutdown on a public highway created an immediate safety risk for me and other drivers. I am filing this complaint because Kia is denying coverage for a federally recognized engine defect due to their own failure to notify the current owner. I am requesting that NHTSA review Kia’s handling of this defect and their use of KSDS as a barrier to coverage. Their failure to notify current owners has resulted in dangerous, potentially life-threatening vehicle failures.

As I was driving going at a rate of 40 MPH my engine shut off. I was able to pull to the side of the road without an accident thankfully. Cranked the vehicle back up and then the same thing it happened again. No check engine light came on either time. Drove for another 200 miles no issues. Going apx. 75 MPH it went into limp mode and check engine light came on and the P1326 code appeared. There is a recall on this vehicle for this code. However the dealership states it’s a knock sensor needing to be replaced and I will have to cover that. The same knock sensor they had me update in 2018 under there advisory. The motor burns apx. 2 quarts of oil every 3000 miles. Requires oil to be added to maintain oil level in between oil changes. Irregular mechanical noise (rattle) during cold start ups. I am scared to drive this vehicle and do not feel I am being treated fairly due to the recalls on this engine.

The contact owns a 2015 Kia Optima. The contact stated while driving at an undisclosed speed, the vehicle lost motive power. There was no warning light illuminated. 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 dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was not available.

My engine recently sustained damage. Although my vehicle’s VIN is listed in the affected recall range, I never received any safety recall notification. I purchased the car in January 2024 while the KSDS recall was still active, yet no one informed me of the recall at the time of sale and I have received no updates since.

The contact owns a 2015 Kia Optima. The contact stated that while his son was driving at 60 MPH, the instrument panel was entirely illuminated, and he pulled over. There was smoke inside the cabin. The occupants were able to exit the vehicle. An independent mechanic opened the hood and noticed a fire. They were able to extinguish the fire. The vehicle was towed to the local dealer, where it was diagnosed that the drive belt had failed and had broken. There was friction from the drive belt, which caused the fire. The vehicle was not repaired. The manufacturer was contacted, who opened a claim. The manufacturer had called the contact, but no further assistance was provided. The approximate failure mileage was 114,000.

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.

The contact owns a 2015 Kia Optima. The contact stated that while driving at 35 MPH and attempting to accelerate, the vehicle entered LIMP Mode, lost motive power, and was unable to accelerate above 30 MPH. The contact was able to pull over to the shoulder of the roadway to turn off the vehicle; however, the vehicle failed to restart. Several unknown warning lights were illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the engine. The contact was informed that the engine needed to be replaced, and the repair could not be covered by the manufacturer because the vehicle had not received the Knock Sensor Detection System (KSDS) ECU upgrade (PI2002D) prior to the failure. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 58,000.

The contact owns a 2015 Kia Optima. The contact stated that while driving at an undisclosed speed, the vehicle lost motive power. There was no warning light illuminated. The vehicle was not able to restart. The vehicle was towed to the residence. The dealer was not contacted. The vehicle was diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 127,000.

The contact owns a 2015 Kia Optima. The contact stated while driving approximately 65 MPH, there was an abnormal knocking sound coming from the engine compartment before the vehicle stalled. The vehicle was towed to the local mechanic who diagnosed and determined that the engine had failed and needed to be replaced. The manufacturer was notified of the failure and advised the contact to tow the vehicle to a local dealer for assistance. The vehicle was towed to the local dealer but was not repaired. The failure mileage was 60,000.

Ive had a recall once before got it fix . Few months later it started smoking from exhaust pipes smoke was white . Took it to kia shop they had told me it was a gasket . Ever since then it has been sitting and ive been paying payments for something i can not drive and for a car i keep having recalls and problems with and I need fix . Kia should have a recall on all motors for 2015 as well . But something needs to be done . Been nothing but issue after issue .