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2018 Hyundai Sonata

Owner reports · Recalls · Investigations

More warning signs than most Sonata years

Owner complaints for the 2018 Hyundai Sonata are substantially higher than the model-year median of 161.

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When problems were reported

Mileage at the reported incident

140 reports with mileage · 232 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 210 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Electrical System. Review the 60 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Power Train. Review the 40 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →

NHTSA owner reports · September 18, 2026 snapshot.

18 crash reports13 fire reports9 injury reports

Fuel/propulsion System complaints

31 reports
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Mileage unknown · Nov 5, 2025
Electrical SystemEngineFuel/propulsion System

Unknown. 2018 Hyundai Sonata engine has failed. Only purchased the vehicle in December 2024, and the engine is defective. There is much information, via research, indicating that Hyundai is aware of the engine issues with this year vehicle, but are unwilling to make amends. Vehicle has 100,189 miles.

NHTSA ODI #11697623

Mileage unknown · Sep 25, 2025
Electrical SystemEngineFuel/propulsion System

Oil consumption was ridiculously high, changing oil/topping off oil constantly. Car would not accelerate over 30 mph without sputtering and rumbling. I had mechanic diagnose bad sparks plugs due to sitting in oil from leaking. After I had them repaired/replaced the car drove great for 1 day, then decided to die in the middle of…

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Oil consumption was ridiculously high, changing oil/topping off oil constantly. Car would not accelerate over 30 mph without sputtering and rumbling. I had mechanic diagnose bad sparks plugs due to sitting in oil from leaking. After I had them repaired/replaced the car drove great for 1 day, then decided to die in the middle of a busy intersection while I had my teenage son in the car with me. My son and I had to PUSH it out of the busy intersection onto a side street to get out of the way! I had it towed to Hyundai dealer who said the spark plugs were bad and that the fuel pressure sensor and gdi pump were faulty and needed replacement. Left front lower control arm/ball joint assembly also requires fix. To the tune of $3000 + . It’s been at dealer for past few months until I can afford the repairs including the 2nd diagnostic and tow it took to get it to dealership.

NHTSA ODI #11689709

Mileage unknown · Aug 7, 2025
Fuel/propulsion System

The fuel pump filter housing is the cause of the malfunction, it is available for inspection upon request. When I am driving I intermittently lose fuel delivery altogether and my car comes to a halt for a second until I press on the gas pedal to get the car going again, this puts myself and other people in danger if my car ran…

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The fuel pump filter housing is the cause of the malfunction, it is available for inspection upon request. When I am driving I intermittently lose fuel delivery altogether and my car comes to a halt for a second until I press on the gas pedal to get the car going again, this puts myself and other people in danger if my car randomly stops while I am driving around others and causes crash risk. An independent service center ran a diagnostic and stated it was the fuel pump filter housing. It has not been inspected by the manufacturer, police, or insurance reps. But it has been inspected by the service center near me. An engine code was produced that pointed to the gas cap, but the gas cap was fine, which indicates fuel delivery issues. There was also shaking during acceleration prior to the incident happening. My VIN does not fall under the current extended warranty, but the issues are identical to the issues of the VINs that do fall under the extended warranty.

NHTSA ODI #11679080

Mileage unknown · Aug 6, 2025
EngineFuel/propulsion System

Urgent Complaint About Repeated Engine Issues on 2018 Hyundai Sonata (VIN: [XXX] ) Hello, I’m writing to file a formal complaint regarding a 2018 Hyundai Sonata, VIN [XXX] , currently financed and still owing $9,700, but the vehicle is no longer reliable or functional. For over a year, the car has had constant mechanical iss…

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Urgent Complaint About Repeated Engine Issues on 2018 Hyundai Sonata (VIN: [XXX] ) Hello, I’m writing to file a formal complaint regarding a 2018 Hyundai Sonata, VIN [XXX] , currently financed and still owing $9,700, but the vehicle is no longer reliable or functional. For over a year, the car has had constant mechanical issues, primarily: •Spark plug failures within weeks of replacement •Repeated misfiring •Constant oil consumption — requiring oil refills every few days •No clear cause ever detected by diagnostic machines Despite replacing the top engine cover, spark plugs, filters, and performing other repairs, the car continues to break down and remains unsafe to drive. These issues began shortly after the 2-year warranty expired in 2023, and have escalated rapidly. This has caused severe financial hardship for my family, who still have to pay nearly $10,000 on a loan for a failing vehicle. I am requesting Hyundai to investigate whether this vehicle qualifies for: •An engine recall, hidden warranty, or class action settlement •A buyback or goodwill repair INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI #11678903

Mileage unknown · Jul 4, 2025
EngineFuel/propulsion SystemPower Train

The engine shuts off, doesn’t start, check engine light flashing, losses power, jerks while driving it, i will get it up yo speed then will shut off or won’t move.

NHTSA ODI #11671246

Mileage unknown · Jun 5, 2025
EngineFuel/propulsion SystemUnknown Or Other

Multiple critical mechanical and safety issues have occurred with my 2018 Hyundai Sonata Sport. The vehicle has experienced persistent engine misfire, a severe oil leak, emissions system failure, and extensive paint deterioration. A certified technician confirmed an active oil pan leak with no dashboard warning lights, posing a …

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Multiple critical mechanical and safety issues have occurred with my 2018 Hyundai Sonata Sport. The vehicle has experienced persistent engine misfire, a severe oil leak, emissions system failure, and extensive paint deterioration. A certified technician confirmed an active oil pan leak with no dashboard warning lights, posing a fire and stalling hazard. To prevent further damage, I replaced the entire oil pan and spark plugs at a personal cost of approximately $800 at Firestone Complete Auto Care. The check engine light revealed diagnostic code P0420 – Catalyst System Efficiency Below Threshold (Bank 1). An O’Reilly emissions scan confirmed the catalytic converter failure, and emissions status was marked “RED.” The vehicle will not pass an OBD-based emissions test. At 149,219 miles, Hyundai refused warranty coverage due to mileage. A certified Hyundai dealership quoted $3,722 to replace both the catalytic converter and valve cover gasket, which remains unaffordable and unrepaired. In addition, the factory-applied white paint began peeling severely from the hood and roof. Although Hyundai issued a warranty extension for this known defect, the dealership refused to repaint the hood, citing a minor dent — even though the peeling is clearly unrelated. The exposed metal has started to rust, risking structural deterioration. All concerns have been evaluated by certified Hyundai service and independent professionals. These combined mechanical, emissions, and exterior failures raise serious safety and durability concerns. I am filing this report to document manufacturer-related defects that may affect other owners of this model and year.

NHTSA ODI #11664986

Mileage unknown · May 24, 2025
EngineFuel/propulsion System

Burns oil fast. 900 miles from an oil change the car oil stick was empty. There are no signs of oil leaking. Every 1000 miles you have to place oil back into it. I’m not the only one complains of this issue. I was reading on Reddit and it’s thousands of people having the same issue.

NHTSA ODI #11662951

Mileage unknown · Mar 27, 2025
EngineFuel/propulsion SystemPower Train

My 2018 Hyundai Sonata (approx. 60,000 miles) began consuming excessive oil, and the engine started smoking while driving. My wife barely made it to the dealership — the car was unsafe, struggled to stay running, and visibly smoked from under the hood. Hyundai acknowledged the oil issue but refused to cover engine replacement. I…

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My 2018 Hyundai Sonata (approx. 60,000 miles) began consuming excessive oil, and the engine started smoking while driving. My wife barely made it to the dealership — the car was unsafe, struggled to stay running, and visibly smoked from under the hood. Hyundai acknowledged the oil issue but refused to cover engine replacement. Instead, they approved a one-time combustion chamber cleaning and requested we drive the car 1,000 miles to "see if it gets better." This is a major safety concern. The vehicle is part of a group of Hyundai models known to have defective Theta II engines that have led to engine failure, fire risk, and recalls. This issue is widespread, and Hyundai is not taking proper responsibility for defective engines in cars like mine.

NHTSA ODI #11651132

Mileage unknown · Dec 31, 2024
EngineFuel/propulsion System

- Component or system that failed: engine (cylinder #4 misfire) - Safety was put at risk twice: once when knock sensor went off on interstate (October) and engine went into limp mode (aka protection mode). Required a tow from the, which was tricky with a vehicle full of passengers. Safety was put at risk gain when vehicle began …

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- Component or system that failed: engine (cylinder #4 misfire) - Safety was put at risk twice: once when knock sensor went off on interstate (October) and engine went into limp mode (aka protection mode). Required a tow from the, which was tricky with a vehicle full of passengers. Safety was put at risk gain when vehicle began to stutter/sputter on interstate (December). Drove 4-cylinder vehicle essentially on three cylinders an hour to dealership - Problem has been confirmed by dealer (Southern States Hyundai, Raleigh, NC) - vehicle has been inspected by warranty inspector, who requests approval before disassembling engine to diagnose issue. However, based upon maintenance records and manufacturer's history of engine issues (more on this below), owner should not be liable for investigating a well known issue. At the time of this writing, the issue has been escalated beyond the dealership and warranty to Hyundai Motor America, and currently awaiting the results of their findings. - symptoms of the problem include constant oil leak from vehicle purchase in May 2024 up to engine failure in December 2024. Various temporary remedies (oil changes and repairs, including oil drain plug gasket replacement, crush washer replacement, and replacement of cracked oil pan) did not fix the issue. Additionally, in the October incident, Hyundai dealership (Sport Durst Hyundai, Durham, NC) simply updated the knock sensor detection (KDS) software, despite the vehicle previously receiving the update in 2019 (this can be verified). Finally, owner, noted "engine knocking" (aka 'tapping') in vehicle prior to engine failure. - Hyundai (the manufacturer) settled a class action lawsuit in 2021. Vehicle is one of the vehicles listed under Class Vehicles, but dealer, nor warranty company, nor Hyundai seem to want to resolve issue, which both alienates owner and presents a safety hazard, as the vehicle is unsafe to drive. All claims here will be supposed via documentation and images.

NHTSA ODI #11633308

Mileage unknown · May 1, 2024
EngineFuel/propulsion System

The motor blew in my 2018 Hyundai sonata due to a manufacturing defect. There was a recall on it a couple of years ago. They acknowledged it was a defect which is why they put an extended warranty on the engine. Because I could not come up with maintenance records dating back until 2018 (I only had them dating back to 2020), the…

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The motor blew in my 2018 Hyundai sonata due to a manufacturing defect. There was a recall on it a couple of years ago. They acknowledged it was a defect which is why they put an extended warranty on the engine. Because I could not come up with maintenance records dating back until 2018 (I only had them dating back to 2020), they denied my motor and will not fix it. I bought the car brand new in 2018 and have had nothing but issues ever since. I have had to change the oil in this vehicle every 2 weeks, because it would be nothing in the oil tank at all. When the recall come out, they said they could not fix the vehicle until the motor was blown. Now that the motor has blew, they won't fix it because I don't have repair records dating back 6 years ago.

NHTSA ODI #11586305

Official recalls

1

21V619000 · Latches/locks/linkages:trunk Lid:latch

Aug 6, 2021

Hyundai Motor America (Hyundai) is recalling certain 2017-2018 Sonata, 2016-2018 Sonata Hybrid, 2018-2020 Accent, and 2016-2017 Azera vehicles. The trunk latch may become damaged, 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, free of charge. Owner notification letters were mailed December 4, 2021. Owners may contact Hyundai customer service at 1-855-371-9460. Hyundai's number for this recall is 208.

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.