2015 KIA OPTIMA Engine Problems

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 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...

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

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...

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?

Engine seized

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...

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 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...

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...

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...

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.

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...

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. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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...

All recalls were not done false input information they never fixed engine bearing recall I’m getting a consultant to handle all the false information being provided by Kia Federico in woodriver

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...

9/25/2025 - our vehicle suddenly stopped in the middle of a busy roadway creating a hazard. We had it towed to [XXX] Kia of Greenville. 9/26/2025 we were advised that the engine had seized with no symptoms and no warning lights. The technician said that it would be covered under the vehicles extended warranty due to the known defect/class action on the Theta II GDI engine documented here: [XXX] 10/2/2025 we were advised the car would NOT be covered under the warranty due to some conflict on a CarFax report. according to CarFax, the vehicle has 82k with 15 maintenance records. This was not a case of neglect by the owner, it is a known defect that Kia is not willing to fix. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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 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 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...

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 .

The car just shut off

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...

I have repeatedly been denied service by KIA Customer Service and KIA Dealerships regarding my safety recall. This ongoing issue has caused significant stress and inconvenience. I am simply requesting that my recall be completed so I can safely operate my vehicle. Despite my efforts, I continue to receive invoices for repairs while being denied the necessary service. I am frustrated by the lack of support and resolution.

The vehicle unexpectedly stalled while idling at a complete stop, posing a serious safety concern. Shortly afterward, the check engine light illuminated. These events occurred around 78,000 miles. Prior to the stall, the engine had been making occasional knocking or tapping noises, particularly at idle. The vehicle was immediately taken to a certified Kia dealership, where a technician diagnosed the issue as engine failure consistent with a known manufacturer recall affecting this vehicle model and year. A recall claim was submitted to the manufacturer, but the repair has been delayed for over a month with no authorization to proceed. No loaner vehicle has been provided. The engine failure puts the driver and others at risk, especially if the vehicle were to stall during active traffic conditions. The problem has been confirmed by the dealership but has not yet been resolved by the manufacturer. Inspection by the manufacturer is still pending....

My 2015 Kia Optima (VIN [XXX] ) case # [XXX] is covered under Kia’s engine recall for potential engine failure/fire. However, Kia and Ray Skillman Northeast Kia, Indianapolis refused to perform the recall repair because I do not have the last two years of oil change records. This is a safety recall, not a warranty claim, and denial of repair violates recall obligations. I am requesting NHTSA’s assistance to ensure Kia complies with the law and replaces the defective engine. Thank you. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

My motor bearing is knocking very loud I was refused service upon arrival dealer was making my service very complicated asking me to go dig up old receipts and various other things that was not actually caused for and I was at risk by driving the car there until it shut off due to engine failures when the car has fire risk and could possibly explode and they have confirmed it’s the engine but have not done any maintenance to my engine the check engine light flashes heavy non stop as well was even denied a loaner car still until today

Purchased 2015 Kia optima LX 4 cylinder. Had the car for 7 months. Driving home car stalled driving into our driveway. When restarted the engine there was a loud noise tapping. Oil light came on. Checked oil it was on empty. No oil light has come on ever before the car stalled. Regular oil changes . Researched the over 900 complaints. Same thing that has happened to everyone else. Thankfully this didn't happen on the drive home in traffic.

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

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.

The contact owns a 2015 Kia Optima. The contact stated while the contact's wife was driving at an undisclosed speed, the vehicle made an abnormal ticking sound. There was no warning light illuminated. The vehicle was taken to an independent mechanic, where the contact was informed that the failure could be related to the engine. The vehicle was then taken to the dealer, where it was diagnosed that the engine had failed. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was filed. The contact was informed that the VIN was included in an unknown related engine recall; however, the engine repair or replacement was not covered under warranty due to missing service documents. The failure mileage was approximately 78,000.

While driving, the engine suddenly shut off without warning. The car coasted to a stop and would not restart. When attempting to start it again, the starter smoked, and the engine would not crank or turn over. This is a serious safety hazard as the engine failure occurred with no warning and matches the symptoms of the known Kia Theta II engine recall for bearing and seizure issues. My VIN is not currently listed as part of the recall, but it experienced the exact same failure. I am requesting that NHTSA investigate and pressure Kia to include my VIN in the recall campaign, as this is a sudden engine seizure defect that could cause a crash if it happens at speed.

The engine seized and is out of commission on 7/16/25.

The contact owns a 2015 Kia Optima. The contact stated while attempting to accelerate from a stop light, the vehicle stalled and failed to restart. The vehicle was later towed to the local dealer who diagnosed that the engine had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 126,000. The VIN was not available.

My car started having electrical issues, started smoking and stopped completely while driving, now it won’t turn on / start

The car makes a raddled noise when turn on and the car turns off when I press the brakes

I own a 2015 Kia Optima (VIN:[XXX]) with a 2.4L GDI engine. The engine has failed — a local repair shop diagnosed it as a “jumped timing” issue, which matches the well-documented Theta II engine defect. I never received recall notice or notice of the required KSDS update. Kia has denied me coverage, stating the update was not done before failure. I now have a vehicle that is undriveable and potentially unsafe. Kia confirmed there is no extended warranty or coverage for rod bearing failure — despite widespread issues — and they ignored my open fire-risk recall (NHTSA 21V331000) in their denial. I am requesting that NHTSA review why my VIN is excluded despite the same failure symptoms, and ask that Kia be required to expand recall eligibility or offer a goodwill resolution. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

My engine went out at 100,000 miles I bought the car with 118,000 mi on it I drove it for 3 years and the engine went out need help

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 NHTSA Hotline to report the failure. The approximate failure mileage was 130,000.

Car was purchased April 2025, I’ve had it less then 2 months and check engine light came on and then flashing. I had it scanned at Auto Zone and was told the code is VVT Solenoid. I had it replaced 6/12/25. I was told by the mechanic that it didn’t solve the issue and metal shavings were on the old one. The car is still constantly going in to limp mode and there’s a knocking noise now. The Auto zone scan listed the mileage as 150,000 yet the car dealership listed and sold it as 101,000. I have a 2015 Kia Optima Ex. The title does not list it as a rebuilt and appeared to be fairly clean and maintained . The mechanic told me the engine needs replaced.

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...

I was driving on the freeway when I noticed smoke coming out of my hood. I immediately exited the freeway, pulled over, popped the hood open, and my engine was on fire. There were no warning lamps on my dash. I don’t know which components were involved and inspection of the components after was not possible, because everything under the hood burned by the time firefighters responded.

I purchased a 2015 Kia Optima 2.4L GDI (VIN: [XXX] ) with a blown engine, which is covered under Kia’s extended engine warranty. I contacted Jim Butler Kia in Chesterfield, MO, where the last service was performed, and requested the free engine replacement under warranty. They acknowledged that the car is covered, but refused to perform the repair because the vehicle is not yet registered. I explained that I have the title in my name and proof of ownership, but cannot register the car in Missouri because it does not run and must pass safety and emissions inspection to be registered. Despite showing them the title and explaining the situation, they continue to deny warranty service. I believe this is unfair and against Kia’s warranty policy, which requires proof of ownership—not necessarily registration. I’m requesting the dealership to honor the warranty and perform the repair, as the issue is known...

The contact owns a 2015 Kia Optima. The contact stated while driving 55-60 MPH, the engine seized. There was no warning light illuminated. The contact inspected the vehicle and became aware of a burning odor around the exterior of the vehicle. The contact attempted to start the vehicle; however, the vehicle failed to start as intended. The vehicle was towed to the residence. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 85,000.