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2018 Kia Optima

Owner reports · Recalls · Investigations

Similar to other model years

Owner complaints for the 2018 Kia Optima do not stand out strongly from the model-year median of 186.5.

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When problems were reported

Mileage at the reported incident

73 reports with mileage · 159 unknown

NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.

What to inspect

Issues worth paying extra attention to based on owner reports.

  • Engine. Review the 131 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Electrical System. Review the 33 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Power Train. Review the 18 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →

NHTSA owner reports · September 18, 2026 snapshot.

10 crash reports10 fire reports7 injury reports

Power Train complaints

18 reports
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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

Mileage unknown · Jan 20, 2025
EnginePower TrainVehicle Speed Control

My engine burns oil very bad. Black smoke comes out of my tailpipe and I burn through 5 quarts in less than a thousand miles. I just got my oil changed two weeks again and I just had to add more oil to my car bc it was empty. I’ve had to replace the spark plugs twice due to soot build up. I can’t afford a new car I’m 17 and can …

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My engine burns oil very bad. Black smoke comes out of my tailpipe and I burn through 5 quarts in less than a thousand miles. I just got my oil changed two weeks again and I just had to add more oil to my car bc it was empty. I’ve had to replace the spark plugs twice due to soot build up. I can’t afford a new car I’m 17 and can barely afford the maintenance let alone a whole new engine. Have spoken to many mechanics and they all say the same thing “it’s a Kia it’s gonna burn oil” ITS A KNOWN ISSUE. And yet Kia will not resolve it bc they don’t want to spend their own money to fix their mistake. I got an estimate for a new engine which is basically crucial and it’s over three grand. No matter where I take it everyone always says the same thing- to get rid of it before it’s too late. But I simply cannot afford to do that and I know my car is not the only one with this issue so many other people with the same car/engine have the same issue. 2.4 L GDI !!!!! I wish someone would have warned me before buying Kia. A recall to fix this issue is needed now. I lose control of the speed sometimes. I will keep my foot at a set position on the throttle and the engine will take off because it’s jumping to the usual power it should have. ( it has reduced power most of the time bc of the struggling engine) sometimes on the highway I’ll get a sudden burst of power and I have to let off the accelerator. Not safe at all

NHTSA ODI #11637108

Mileage unknown · Jan 18, 2025
Power Train

It burns oil constantly. I constantly have to get new filters put on because they become black very quickly same with the oil itself. The engine has a tic and I know other people with optima’s that have the same problem. I burn through 4 quarts in two weeks- less than 600 miles.

NHTSA ODI #11636731

76,270 miles · Oct 1, 2024
EnginePower Train

The contact owns a 2018 Kia Optima. The contact stated while driving approximately 40 MPH, the accelerator pedal was depressed; however, the vehicle failed to respond as needed. The contact stated that there was an abnormal growling sound coming from under the floorboard, and the engine was making an abnormal knocking sound. The…

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The contact owns a 2018 Kia Optima. The contact stated while driving approximately 40 MPH, the accelerator pedal was depressed; however, the vehicle failed to respond as needed. The contact stated that there was an abnormal growling sound coming from under the floorboard, and the engine was making an abnormal knocking sound. The contact stated that the RPM gauge was revving high while depressing the accelerator pedal; however, the vehicle failed to respond. The contact pulled over and turned off and restarted the vehicle; however, the vehicle was not running normally. The contact stated that the failure was a recurring failure. Additionally, the contact stated that vehicle was consuming approximately one quart of engine oil per week and the transmission was hesitating and was making the vehicle jerk while shifting gear. The contact had taken the vehicle to an independent dealer, but the vehicle was not diagnosed or repaired. The manufacturer was informed of the failure. The failure mileage was 76,270.

NHTSA ODI #11617527

Mileage unknown · Sep 20, 2023
EnginePower TrainVehicle Speed Control

Car will NOT go pat 60mph and i haven’t had this car just over 6 months. And the camshaft sensors are gone out. Smoke comes out the pipe when mash on gas…. It is really a bad vehicle. And Southeast auto refuses to fix it. I really honestly think the motor is bad in it. Because I been having issues with it since I had it

NHTSA ODI #11545624

Mileage unknown · Aug 8, 2023
EngineFuel/propulsion SystemPower Train

I'm reporting these issue pertaining to the engine within the first 3 weeks AFTER the engine replacement recall was serviced and completed. The vehicle was exhibiting the same defects and major health and safety hazards as before the new engine. Intermittent engine failure, even worse, while i was trying entering the hwy at spee…

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I'm reporting these issue pertaining to the engine within the first 3 weeks AFTER the engine replacement recall was serviced and completed. The vehicle was exhibiting the same defects and major health and safety hazards as before the new engine. Intermittent engine failure, even worse, while i was trying entering the hwy at speeds of 45-50 miles it jerked very violently and loss total power while vehicles were behind me nearly rear ended. Prior to this I reached out multiple times to have it serviced at again. The original service department didn't respond, so I called other service departments and was told it needed to be serviced by the original dealership/service department that replaced the engine. I had the vehicle in normal working conditions a few days before it began exhibiting the same problems as before the engine replacement. It was in operable condition but still stalling and refusing to crank unless primed, until it ultimately just would not crank at all and is back in the same condition it was before the new engine but it is not locked up currently. The time frame and Milage between first experiencing the issues to now, March 2023-64745 Started shuddering, loss of power while driving, but would crank right back up without issues. Happened a few times, charged up battery thinking is was am electrical issue. April 2023 More frequently the issues occurred, still same severity levels. May 2023 Began happening every time at an idle, whether I was at a fast food in drive through placing an order, or to wash the car. Every time at an idle this would happen, and would take a few times of trying to start the vehicle and after about 5 seconds of cranking it would catch and work. I began placing the vehicle in neutral while at idle and it would assist In the stalling out sometimes. After a few days of this it refused to crank due to the engine locking up. Milage at this time was 68048. Aug 2023-New engine, drove about 2k miles-70207 current

NHTSA ODI #11537251

Mileage unknown · Jun 1, 2023
Power TrainUnknown Or OtherVehicle Speed Control

Ever since I got my car I’ve had black oil since the start . Second my car breaks on its own at times 3rd my car system keep breaking down as the sparks leaking in some where has this issue since bought it 2 years ago low miles

NHTSA ODI #11524862

60,000 miles · Mar 3, 2023
Power Train

The contact owns a 2018 Kia Optima. The contact stated that while driving at an undisclosed speed, the vehicle was jerking. The vehicle was taken to the dealer; however, no cause for the failure was found. The vehicle was then taken to Battleground Kia of Greensboro (2927 Battleground Ave, Greensboro, NC 27408) but no cause for …

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The contact owns a 2018 Kia Optima. The contact stated that while driving at an undisclosed speed, the vehicle was jerking. The vehicle was taken to the dealer; however, no cause for the failure was found. The vehicle was then taken to Battleground Kia of Greensboro (2927 Battleground Ave, Greensboro, NC 27408) but no cause for the failure was found. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 60,000.

NHTSA ODI #11510005

Mileage unknown · Oct 26, 2022
Power Train

UNKNOWN When slowing to a stop, the vehicle spontaneously makes a sudden jolt, throwing passengers forward. It’s as if the the transmission malfunctions when down shifting and results in engine braking.

NHTSA ODI #11491042

Mileage unknown · May 9, 2022
EngineLane DeparturePower Train

Engine overhead and stopped working in addition to it consuming massive amounts of oil without physically putting oil in. I've went to 2 dealerships who refuse to provide me with a new engine even though I'm covered under the engine extension warranty due to me having the knock sensor update done. I am now involving my attorney …

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Engine overhead and stopped working in addition to it consuming massive amounts of oil without physically putting oil in. I've went to 2 dealerships who refuse to provide me with a new engine even though I'm covered under the engine extension warranty due to me having the knock sensor update done. I am now involving my attorney and will go to the news channels to inform how kia manufacturer has become a disgrace with not providing quality engines in their vehicles and don't want to be responsible for it. there's already a settlement going on for kia optimas and other cars they've made because of faulty engines. They can better believe I'm coming for them next with a lawsuit.

NHTSA ODI #11463963

Official recalls

2

23V594000 · Latches/locks/linkages:trunk Lid:latch

Aug 24, 2023

Kia America, Inc. (Kia) is recalling certain 2016-2017 Rio, 2016-2018 Optima, 2017-2018 Optima Hybrid and Optima Plug-in Hybrid vehicles. The trunk latch base may crack, preventing the opening of the trunk from the inside. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 401, "Internal Trunk Release."

Consequence & remedy

Consequence: A person inside the trunk compartment may become trapped, increasing their risk of injury.

Remedy: Dealers will replace the trunk latch base subassembly, free of charge. Owner notification letters were mailed October 19, 2023. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC278.

18V161000 · Hybrid Propulsion System

Mar 8, 2018

Kia Motors America (Kia) is recalling certain 2017-2018 Kia Optima hybrid vehicles. These vehicles are equipped with a Voltage Protection Device (VPD), designed to protect the high voltage battery module, that may activate inadvertently.

Consequence & remedy

Consequence: If the VPD activates while the vehicle is being operated in Electric Vehicle (EV) mode, there may be a loss of power, increasing the risk of a crash.

Remedy: Kia will notify owners, and dealers will remove the VPD switch and install two newly designed Battery Management Systems (BMS) that contain Overvoltage Protection Devices (OPDs), free of charge. The recall is expected to begin May 2018. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC162.

Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗

NHTSA investigations

2

DP22003 · 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.