NHTSA owner reports · September 18, 2026 snapshot.
What owners actually said
232 reportsMileage unknown · Jul 11, 2025
Engine
Engine failed despite maintenance and repairs. The car is part of the active class action for Kia Engine Defects. The KSDS software was never installed as we were never notified about the recall by kia. As a result, Kia denied coverage under the engine defect class action settlement. We need this vehicle repaired or compensation…
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Engine failed despite maintenance and repairs. The car is part of the active class action for Kia Engine Defects. The KSDS software was never installed as we were never notified about the recall by kia. As a result, Kia denied coverage under the engine defect class action settlement. We need this vehicle repaired or compensation for replacement
NHTSA ODI #11672753
Mileage unknown · Jul 10, 2025
Fuel/propulsion SystemService BrakesVehicle Speed Control
Purchased car about 4 months ago, before warranty ran out, the shop looked at it told me it was fine, it wouldn't accelerate. Few weeks later same issue but all my oil was gone, they found 11 things wrong with the vehicle, told me warranty wouldn't take care of it unless the engine blow up. The salesman Scottie Mitchell told me…
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Purchased car about 4 months ago, before warranty ran out, the shop looked at it told me it was fine, it wouldn't accelerate. Few weeks later same issue but all my oil was gone, they found 11 things wrong with the vehicle, told me warranty wouldn't take care of it unless the engine blow up. The salesman Scottie Mitchell told me check Kia for recalls, called Kia 3 recalls, they were trying to finance another car higher, back wanted to know why the dealership didn't know about recalls, Kia place did call a Robert. One of the owners did know about recalls, why dealership didn't pass them on. They trying to sell me a higher vehicle to keep cover the cost of the one I got 1st
NHTSA ODI #11672508
Mileage unknown · Jul 9, 2025
Electrical SystemEngine
The car is literally burning through oil so bad every other week I am putting more in, the electrical system continues to fail and shorts, the motor sounds like it is ticking now due to the oil consumption.
NHTSA ODI #11672225
Mileage unknown · Jul 3, 2025
Engine
The 2.4L Theta II engine in my 2018 Kia Optima is failing, exhibiting excessive oil consumption, with oil loss documented at over 1 quart per 1,000 miles, leading to secondary failures in the catalytic converter, clogged with oil carbon and breaking into pieces that may damage the cylinder walls, and the spark plugs, which are f…
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The 2.4L Theta II engine in my 2018 Kia Optima is failing, exhibiting excessive oil consumption, with oil loss documented at over 1 quart per 1,000 miles, leading to secondary failures in the catalytic converter, clogged with oil carbon and breaking into pieces that may damage the cylinder walls, and the spark plugs, which are fouled with carbon, causing misfires. The engine and related components remain intact and un-repaired, pending Kia’s required 3,000-mile consumption test. Safety of drivers have been put at significant risk. The excessive oil consumption and potential engine seizure threaten sudden loss of power, especially on freeways where car fails to accelerate to city and highway speeds, increasing the chance of a collision. The clogged catalytic converter poses a fire hazard, (reported by NHTSA investigations into Theta II) where oil leaks or debris can ignite on hot surfaces. Risk is heightened during the mandated 3,000-mile test as well. Problem has been confirmed by both a dealer and an independent service center as recent at 1 July, '25, documenting oil loss and new engine recommendation. Symptoms began with noticeable oil loss during oil changes, starting at least 1 quart per interval on May 10, 2023 (mileage 43,374), with the loss increasing over time. Misfires and RPM loss during acceleration first appeared after the oil valve gasket replacement in late May 2025, and freeway pickup issues became apparent around mid-June 2025. The full engine failure was confirmed by Spitzer on July 01, 2025.
NHTSA ODI #11671015
Mileage unknown · Jun 15, 2025
Engine
Got an oil change, and they advised that it was low on oil. (I had just replaced it recently) I took it to the dealer and they advised a part was bad, that they replaced. I was driving and the check engine light and oil light came on . I had to tow car. Dealer said the engine was burning oil, and that the engine is covered, but …
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Got an oil change, and they advised that it was low on oil. (I had just replaced it recently) I took it to the dealer and they advised a part was bad, that they replaced. I was driving and the check engine light and oil light came on . I had to tow car. Dealer said the engine was burning oil, and that the engine is covered, but I would have to drive it until it got worse.
NHTSA ODI #11667034
Mileage unknown · Jun 12, 2025
Engine
Subject: Urgent Request for Engine Replacement – 2018 Kia Optima Dear Kia Consumer Affairs, I am writing to formally report a recurring and increasingly dangerous engine issue with my 2018 Kia Optima, and to request immediate assistance, including consideration for an engine replacement due to ongoing safety and reliability c…
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Subject: Urgent Request for Engine Replacement – 2018 Kia Optima Dear Kia Consumer Affairs, I am writing to formally report a recurring and increasingly dangerous engine issue with my 2018 Kia Optima, and to request immediate assistance, including consideration for an engine replacement due to ongoing safety and reliability concerns. Since June 2024, I have routinely visited the Kia dealership on a near-monthly basis for service due to persistent problems with excessive oil consumption and spark plug failures. Each visit has resulted in service-related expenses, despite my efforts to maintain the vehicle in accordance with manufacturer recommendations. Unfortunately, the issue has not been resolved and continues to worsen. Most recently, on [XXX], I experienced a critical incident. While driving, the engine began shaking aggressively, the check engine light illuminated, and smoke was detected coming from the engine compartment. Out of concern for my safety, I immediately pulled over and had the vehicle dropped off at a nearby garage for emergency inspection. This incident, combined with the repeated monthly service visits and associated costs, clearly indicates a systemic issue that may be linked to known engine defects in similar Kia models. I urge Kia to review my case for warranty coverage, recall eligibility, or goodwill engine replacement assistance. I have attached supporting documentation including service records, receipts, and oil consumption logs. Please advise on the next steps for resolving this matter. Thank you for your attention. I look forward to your prompt response. Sincerely, [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA ODI #11666542
Mileage unknown · Jun 4, 2025
Electrical SystemEnginePower Train
There is already the theta 2 campaign on my Kia optima but Kia is not upholding their warranty for a new engine. Kia customer care told me that untill my car actually throws a rod then they will not fix it. So I could be doing 80 down the freeway and jeopardize not only my safety but everyone else's for them to uphold their life…
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There is already the theta 2 campaign on my Kia optima but Kia is not upholding their warranty for a new engine. Kia customer care told me that untill my car actually throws a rod then they will not fix it. So I could be doing 80 down the freeway and jeopardize not only my safety but everyone else's for them to uphold their lifetime warranty? Also upon doing further investigation and I don't know how many cars this pertains to but the fuse box in my 2018 actually belongs to a 2016 which if you look it up yes they are comparable but don't offer all the same functions or power that my 2018 needs to run I fully believe Kia knew this when they were being built on the factory line because it just so happens that there is about 6 different versions to the pcb relay that can fit from a 2016 to a 2020 k5 but for some odd reason every car got something different why?
NHTSA ODI #11664974
146,000 miles · May 23, 2025
Engine
The contact owns a 2018 Kia Optima. The contact stated while driving 70 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. The contact turned off the cruise control; however, the failure persisted, and the vehicle stalled. The contact stated that the check oil warning light was illuminated.…
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The contact owns a 2018 Kia Optima. The contact stated while driving 70 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. The contact turned off the cruise control; however, the failure persisted, and the vehicle stalled. The contact stated that the check oil warning light was illuminated. The contact was able to coast to the side of the road. The vehicle failed to restart, and the vehicle was towed to a service station. The vehicle was then towed to a dealer where it was diagnosed and determined that the high-pressure fuel pump had failed, causing fuel intrusion into the engine and engine failure. The vehicle was not repaired due to the cost. The manufacturer was not made aware of the failure. The failure mileage was approximately 146,000.
NHTSA ODI #11662780
96,145 miles · May 22, 2025
Air BagsCrash
The contact called on behalf of his son who owned a 2018 Kia Optima. The contact stated that while driving at approximately 25 MPH, the front of the vehicle crashed into the rear end of the vehicle that was in front of him whom made a sudden stop. The contact was concerned that the air bags were not deployed. No warning lights w…
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The contact called on behalf of his son who owned a 2018 Kia Optima. The contact stated that while driving at approximately 25 MPH, the front of the vehicle crashed into the rear end of the vehicle that was in front of him whom made a sudden stop. The contact was concerned that the air bags were not deployed. No warning lights was illuminated. A police report was filed. No medical attention was sought, and no injuries were sustained. The vehicle was pronounced totaled at the scene. The contact attempted to contact the manufacturer however, received no response. The failure mileage was 96,145.
NHTSA ODI #11662673
Mileage unknown · May 14, 2025
Engine
This vehicle has an active recall: SC218 / DTC P1326 – ECU UPDATE / ENGINE REPAIR. I brought it to Martin Kia in Newark, Delaware, but they refused to perform the recall stating that since the vehicle is owned by a used car dealer, the recall is not applicable. They also provided a written statement saying that the extended warr…
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This vehicle has an active recall: SC218 / DTC P1326 – ECU UPDATE / ENGINE REPAIR. I brought it to Martin Kia in Newark, Delaware, but they refused to perform the recall stating that since the vehicle is owned by a used car dealer, the recall is not applicable. They also provided a written statement saying that the extended warranty does not apply because I am a dealer, and that they will not perform any recall work until the vehicle is owned by a “customer.” However, federal law requires all safety recalls to be completed free of charge, regardless of the vehicle’s current ownership status or whether it is owned by a dealership. This is a safety issue and refusal to perform recall work puts future drivers at risk. I have attached the letter they gave me for your reference. I kindly request your urgent review of this case and enforcement action to ensure the dealership complies with federal recall obligations.
NHTSA ODI #11660972
NHTSA investigations
2DP22003 · Loss Of Motive Power
Opened Sep 12, 2022 · Closed Dec 12, 2023
Status: closed (inferred from source dates) · Engine
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021. The Petitioners cited examples of complaints indicating that the subject vehicles were experiencing rapid loss of engine oil due to oil drain plug back outs, resulting in loss of motive power and/or catastrophic engine damage. Additional complaints were provided which alleged that the oil drain pans lack sufficient structural integrity and are susceptible to cracking. The petition itself can be reviewed at NHTSA.gov under ODI number 11481745. On September 12, 2022, the Office of Defects Investigation (ODI) opened Defect Petition (DP22-003) to evaluate the Petitioners’ request. The Petitioners have provided additional complaints within four supplemental letters dated January 31, 2023, March 21, 2023, May 23, 2023, and August 4, 2023. ODI’s evaluation included the review and analysis of the complaints and supporting information submitted by the Petitioners, as well as additional complaints submitted directly to NHTSA which referenced either the oil drain plug or a crack in the oil pan. After reviewing the available data, ODI has not identified evidence that would support opening a defect investigation into the oil drain pan assemblies of the subject vehicles. Based on a review of the available information, a loss of motive power resulting from an oil drain plug back out has not occurred between the initial sale of a vehicle and the completion of its first oil change. If during an oil change service, a technician fails to remove the existing drain plug gasket before installing a new gasket, it is likely that a proper seal between the drain plug and the oil pan will not be made. An improper seal between the drain plug and oil pan could lead to the backing out on the drain plug, resulting in the sudden loss of oil while driving. Additionally, the provided examples of oil pan cracks were localized to the immediate vicinity of the oil drain plug and/or appeared to be the result of direct-contact with a tool during servicing. There is no information to support that a vehicle-based defect exists relating to the oil pan assembly, and instead the documented incidents are related to the failure to follow the proper maintenance procedures during oil change service. In October 2023, Hyundai published a Technical Service Bulletin (TSB) that provided detailed instructions for oil change service on its gasoline powered vehicles, specifically highlighting the need to remove and replace the existing drain plug gasket prior to reinstalling the drain plug. After a thorough review of the material submitted by the petitioner, the information already in NHTSA's possession, and the potential risks to motor vehicle safety implicated by the petitioners' allegations, NHTSA does not believe that a formal investigation is warranted. Therefore, the petition is denied. A Federal Register Notice (FRN) further detailing NHTSA’s reasons for denial of the petition will be published. The reference numbers for the complaints to NHTSA cited by the petitioner can be found in the petition submission documents in the public file for DP22-003. To review those complaints and the additional complaints ODI added to its evaluation which are cited in the Closing Resume ODI Report Identification Number document, go to NHTSA.gov.
EA19001 · Electrical Overstress
Opened Apr 19, 2019 · Closed Sep 19, 2024
Status: closed (inferred from source dates) · Air Bags: Air Bag/restraint Control Module
The Office of Defects Investigation (ODI) opened this investigation to determine if the failure of airbags to deploy during severe crashes, in certain vehicles, was the result of a safety related defect. During the investigation a complex failure was studied that can result in non-deployment of subject vehicle air bags and other restraint system devices in severe crash events. The subject vehicles may be equipped with an airbag control unit (ACU) for the supplemental restraint system (SRS) Electronic Control Unit (ECU) manufactured by ZF-TRW. The ECU receives signals from crash sensors mounted in the vehicle and deploys the vehicle air bags and seat belt pretensioners in accordance with manufacturer design specifications. The ECU in the subject vehicles contains a model DS84 application-specific integrated circuit (ASIC) which controls the communication of the crash sensor signal, firing commands (i.e., when to deploy the airbag(s) and/or pretensioners), and fault information (e.g., diagnostic trouble codes). In September 2016, FCA announced recall 16V-668 for certain model year (MY) 2010 to 2014 Chrysler, Dodge and Jeep products manufactured with the subject ZF-TRW ACU. In this recall, FCA discussed an EOS condition that resulted in a failure of the subject DS84 ASIC, which caused air bag non-deployment. FCA noted that the defect condition had only been observed in vehicles equipped with sensor harnessing routed across the front of the vehicle. Other FCA vehicles that also used the subject ACU, but were not equipped with cross-car harnessing, had not experienced EOS failures, despite similar time in service. During the course of this investigation, ODI sent two separate Information Request (IR) letters to six vehicle manufactures (including FCA, Hyundai, Honda, Kia, Mitsubishi, and Toyota) and one IR letter to ZF-TRW. These IR letters resulted in ODI receiving comprehensive data from these manufacturers and suppliers. Studies of this data found that the DS84 ASIC does not have sufficient protection against negative electrical transients or electrical overstress (“EOS”) that can be generated in certain severe crashes. An electrical transient occurs when the electrical power supplied to a circuit changes momentarily over a short duration of time. In these severe crash cases, the crash sensors and other powered wiring can be damaged and short circuited so as to create a negative electrical transient of sufficient intensity and duration (that are outside the vehicle manufacturer's specification) to damage the ASIC before the restraint device deployment signal is received by the SRS ECU. This damaged signal can lead to incomplete or nondeployment of the air bags and/or pretensioners. Airbag non-deployment and/or lack of pretensioner operation can increase the risk or severity of injury in a crash.A total of 8 fatalities and 14 injuries were associated with known EOS events. The common element in all investigated manufacturers vehicles is the SRS ECU containing a DS84 ASIC manufactured by ZF-TRW. The risk associated with the ASIC is equally shared among all OEMS involved in the investigation. The actual real-world risk can be mitigated by other factors which were assessed by ODI during this investigation. The first mitigating factor involves protections built into the ACU design which protect the DS84 ASIC from damage. There are multiple strategies and levels of protection employed by different OEMs that provide effective EOS mitigation. The two most common strategies at the ACU level are circuit protection diodes on the remote senor signal lines, and current limiting resistors that protect critical components. The second mitigating factor is found at the vehicle level and involves the location and routing of the wires leading from the crash sensors to the SRS ECU. If the wires are well protected in a crash and are not routed with other power wires carrying large currents, the risk for an EOS event is significantly reduced or eliminated. These design specific factors combine to produce a spectrum of risk for the vehicles equipped with ACUs using the DS84 ASIC. Given the many of years of field exposure, it is possible to divide the subject population into two groups; vehicles which have experienced EOS events, and vehicles which have not experienced EOS field events. Four of the six OEMs involved in this investigation have experienced EOS field events on at least one of their models equipped with a DS84 ASIC. All vehicle models (including the Toyota models identified in the Failure Report Summary of the opening resume for this investigation) with field events have been recalled. In an abundance of caution, ODI kept this investigation open five years to monitor field performance and did not identify any field events on vehicles not included in existing safety recalls. Given the spectrum of risk identified in this investigation and that all vehicles with a demonstrated unreasonable risk have been recalled, ODI is closing this investigation. ODI is closing this investigation with the following manufacturer safety recalls: 16V-668, 18E-043, 18V-137, 18V-363, and 20V-024. With the recall actions taken by the subject vehicle and equipment manufacturers, this investigation is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exists on other model or model year vehicles outside of the recall scopes. The agency reserves the right to take further action if warranted by the circumstances.