2015 Kia Optima transmission & drivetrain problems

Related recalls

No recalls on file.

What owners say

1. Filed Jun 8, 2026AZEngineTransmission & Drivetrain

   P1326 code flashing engine light knock sensor went out 3 times in 6 months and just replaced it again and this time engine light didn't go off I was reading that there was a recall on this but apparently mine doesn't state it. Car cannot pass emissions if engine light is on and the 15th of June is approaching. The car doesn't make any sounds or nothing.

   NHTSA complaint #11742779 · source
2. Filed Feb 13, 2026CAEngineTransmission & Drivetrain

   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…

   NHTSA complaint #11717931 · source
3. Filed Nov 23, 2025TXEngineFuel, Hybrid & EV PropulsionTransmission & Drivetrain

   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…

   NHTSA complaint #11701029 · source
4. Filed May 20, 2025CAEngineTransmission & Drivetrain

   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…

   NHTSA complaint #11662125 · source
5. Filed Apr 10, 2025TXElectrical SystemFuel, Hybrid & EV PropulsionTransmission & Drivetrain

   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…

   NHTSA complaint #11653852 · source
6. Filed Apr 3, 2025OHElectrical SystemEngineTransmission & Drivetrain

   Was driving down the highway and all of a sudden the car shut down in the highway lucky cars was not close by. Tried to crank it it would not crank would not take a boost it won’t say anything I had the battery checked at auto zone the battery is really good. The mileage on the Kia optima is 1,900 actual miles it will not crank or move it was very scary I called Kia customer service there wanted to charge me over $400.00 dollars to come get it and take it to the shop so it…

   NHTSA complaint #11652671 · source
7. Filed Aug 5, 202488,000 miSCEngineTransmission & Drivetrain

   The contact owns a 2015 Kia Optima. The contact stated that while driving at various speeds, or while at a complete stop, the vehicle would shut off without warning. The vehicle would resume normal operation upon restart of the engine. The vehicle was taken to a dealer for an inspection; however, the dealer was unable to duplicate the failure. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 88,000.

   NHTSA complaint #11606492 · source
8. Filed Jul 17, 2024120,000 miCATransmission & Drivetrain

   The contact owns a 2015 Kia Optima. The contact stated while driving at an undisclosed speed, the vehicle lost motive power and stalled. There were no warning lights illuminated. The vehicle was towed to the residence and then to a local dealer where it was diagnosed with a wheel bearing failure. The vehicle was not repaired. The manufacturer was made aware of the failure; however, no assistance was provided. The failure mileage was approximately 120,000.

   NHTSA complaint #11603025 · source
9. Filed Jun 1, 2024AZTransmission & Drivetrain

   Driving one day in Dec 2021, and there was a hybrid system warning and vehicle suddenly stopped on the road. Called tow truck. We were unable to put the car in neutral to tow. Had tow truck deliver to dealership for diagnostic and repair. Dealer replaced transmission and stated it was covered under warranty. Finally got vehicle back and warning still pops on dashboard. We’ve taken it back several times and warning randomly appears. Dealership unable to recreate the warning…

   NHTSA complaint #11591929 · source
10. Filed Mar 24, 2024CAElectrical SystemEngineTransmission & Drivetrain

    I need remedy compensation in regards of my recalls my engine warranty was gone after being replaced due to engine seized 01/01/2023 i had engine warranty since 2020 and now my car was being rejected refused rejected excluded iam being discredited i own my 2015 kia optima i lived sleep in my car iam hoing through financial hardship since 2021 i need legal advice help assistance please

    NHTSA complaint #11579201 · source
11. Filed Dec 12, 2023CATransmission & Drivetrain

    The vehicle has a seized motor within the manufacturers powertrain warranty. They are denying to repair/ replace the motor because they claim a recall was not performed. The NHTSA does not currently show the recall that needed to be performed. The vehicle should still be covered by KIA's powertrain warranty and the dealer is not accepting responsibility.

    NHTSA complaint #11559762 · source
12. Filed Dec 8, 2023WABrakesEngineTransmission & Drivetrain

    1. While stepping on the brakes my car has revved up as if I was pressing the gas. So I let my foot off the pedal and pressed the brakes again. This happened 2 times that week. And another time while I was coming to a stop light as I pressed the brakes, my car revved up but didn’t actually make my car speed up. I had to press the brakes again for it to stop. 2. My battery was smoking and I replaced it. 3. My car is consuming oil. The dealership did a series of oil…

    NHTSA complaint #11559073 · source

Source: U.S. National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation public data. Complaints are submitted by owners and are not verified by NHTSA or by us; a complaint does not prove a defect exists. View this vehicle on NHTSA.gov Methodology