2017 Hyundai Sonata

764 complaints on file, page 1 of 39.

1. Filed Sep 22, 2026Failure Aug 28, 2026Bakersfield, CAEngine

   I am reporting an unaddressed, critical safety defect involving the Theta II engine in my 2017 Hyundai Sonata. The engine has developed a severe internal metallic knocking noise consistent with connecting rod bearing failure—the exact manufacturing defect associated with Hyundai's major engine recall campaigns (such as Recall 198 / Campaign 966)

   NHTSA complaint 11766104
2. Filed Sep 16, 2026Failure Sep 9, 2026Loxahatchh, FLUnknown or other

   I was driving down the road when my sunroof glass completely ripped away from the top and flew off. The glass is gone but the frame is still there but bent. I took it to a auto glass repair shop that stated "sunroof glass separated from urethane, came off and bent frame." I am dropping off at Hyundai dealership 9.17.26 to have them inspect. My insurance will not cover repairs. So I am hoping maybe this has happened to other people. There was a recall on sunroofs for the 2014-2016 Hyundai Sonata's NHTSA campaign 16V726000 A bonding issue with the front sunroof wind deflector anchor plate can cause the deflector to come loose and jam the glass panel when closing, or detach entirely while the car is moving.

   NHTSA complaint 11764613
3. Filed Sep 4, 2026Failure Jan 1, 2026Green river, UTEngine

   The vehicle suffered a sudden, catastrophic internal mechanical engine failure out of nowhere without any warning lights or previous symptoms. An inspection of the engine cylinder revealed a physical hole blown through the top of the Cylinder 2 piston, causing immediate and complete loss of engine compression. This sudden structural failure caused the vehicle to completely lose all propulsion and stall unexpectedly while in operation, creating an immediate, severe safety hazard on the road.This vehicle features Hyundai's 2.4L Theta II Gasoline Direct Injection (GDI) engine, a family with a well-documented history of manufacturing defects, severe oil consumption, and catastrophic internal structural failures. Because this failure occurred instantly and without a progressive warning, it put occupants at risk of a severe rear-end collision or stranding in an unsafe traffic pattern. I am filing this safety report because the catastrophic destruction of the internal engine components presents a persistent and dangerous hazard to public safety.

   NHTSA complaint 11762255
4. Filed Jul 26, 2026Failure Jun 11, 2026Ft Pierce, FLEngine

   We had a recall done, Campaign 92C, and every since then the car drives horrible. It's worse when cool, it sputters, and hesitates especially when excellerating. Even after warmed up it seems to slam in and out of gear at low speeds, even when foot is not on the gas. The drive is choppy. The dealership told us to drive it and let the transmission "learn" our driving patterns, but it has not resolved itself. Before campaign car ran smooth, now shuttering and sputtering.

   NHTSA complaint 11752878
5. Filed Jul 25, 2026Failure Jun 1, 2026Bellmead, TXElectrical system, Seats, Steering

   I was driving and all of a sudden the traction lights turned on and the sterring wheel is hard to turn. Almost go in a car accident. The windows just stopped working and the brakes light constantly keep getting burned out.

   NHTSA complaint 11752817
6. Filed Jul 21, 2026Failure Jul 11, 2026Rowlett, TXElectrical system, Engine, Fuel/propulsion system

   I am writing to report a direct violation of the Theta II Class Action Settlement terms by Hyundai Motor America. This morning , I emailed an Executive Case Manager explicitly explaining that my 2017 Sonata has an active P1326 code, has the 2019 KSDS update, and requires a mandatory diagnostic under NHTSA Recall 17V226 that cannot be denied due to a salvage title. Instead of replying to my facts, the Case Manager Kathy gave me a hard denial falsely framing my federal recall safety request as a "voluntary goodwill warranty" issue to justify her rejection. Please help me in getting authorization my car with Hyundai dealership in Plano Tx to run the bearing rod test and get it fixed.

   NHTSA complaint 11751813
7. Filed Jul 6, 2026Failure Jun 25, 2026Clermont, FLEngine, Unknown or other

   My engine seemed to be consuming oil way to much I had to do a oil change at 61,000 recommend by tire plus but at 58,000 is when I had to change my oil I also noticed there is a buring smell and its also been leaking oil at times I went to get it checked out by a mechanic at tireplus but they also they are seeing that the oil consumption was not normal and they recommend a possible recall for it because it hazardous for how fast its consuming and the leaks

   NHTSA complaint 11748628
8. Filed Jun 30, 2026Failure Jun 19, 2026Hagerstown, MDEngine

   Driving home from work on [XXX] (not a safe location)when my car lost power and engine light began to flash. I pulled off to the side of road and called my dad. He came with a code reader and said there was a code P1326. He cleared the code and car drove normally again. 2 days later it began to run rough. I was told about the engine recall so I called Hyundai corporate and told them this same story. I was advised to take to dealership and have the “rod bearings inspected” and shouldn’t matter that my dad cleared the code. The dealership(Massey Hyundai MD) said it had a burnt valve and not part of warranty. But never checked rod bearings. When I called corporate. They said nothing they could do. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

   NHTSA complaint 11747509
9. Filed Jun 23, 2026Failure Aug 29, 2025Preston, MOEngine

   High oil consumption, burning a quart of oil or more every 500 miles since bought used at Hyundai dealership.

   NHTSA complaint 11745870
10. Filed Jun 22, 2026Failure Sep 26, 2021San Diego, CAElectrical system, Engine, Power train

    My 2017 Hyundai Sonata SE, equipped with the Theta II 2.4L GDI engine, is experiencing severe powertrain failures including rhythmic metallic engine knocking, catastrophic oil consumption, and un-commanded surges/jumping in speed while driving. These symptoms manifested following an unauthorized engine replacement performed by Hyundai of El Cajon under Repair Order [XXX], where the dealer covertly outsourced my vehicle to a third-party shop (Legacy Motor Works) to install an unverified used salvage engine block rather than a certified factory assembly. This vehicle is a Class Vehicle under In re: Hyundai and Kia Engine Litigation (Case No. [XXX]), and the KSDS software update (Campaign 953) was successfully completed on my vehicle in 2019. The engine knock, surging, and oil consumption are consistent with the known connecting rod bearing failure defect described in NHTSA investigation PE17-007. The dealership is currently denying warranty coverage, citing a mileage limit that does not exist under my Lifetime Powertrain Warranty, and they are withholding physical documentation of the repair terms. The vehicle is also experiencing secondary safety failures, including a continuous airbag SRS warning light (two years) and electrical shorts caused by the salvage-yard alternator installation, which have destroyed 4 to 5 car batteries. This engine failure represents a significant safety hazard, as the vehicle periodically loses power and surges without driver input. I am requesting that NHTSA investigate this pattern of warranty denial, parts-sourcing fraud, and the safety risks posed by this substandard engine installation. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

    NHTSA complaint 11745609
11. Filed Jun 11, 2026Failure May 11, 2026North Easr, MDAir bags, Steering

    The RED light is lit on the dashboard for the airbag. Unable to use steering wheel electronic features which helps with and was designed for hands free controls. I am unable to cycle through the electronic features or engage the cruise control due to the steering wheel electronics are in-op. Please help and get a recall started. This is not on the consumer.

    NHTSA complaint 11743557
12. Filed Jun 6, 2026Failure May 27, 2026Philadelphia, PAEngine, Power train, Suspension

    [XXX] [XXX] [XXX]; [XXX] [XXX] [XXX] Date: XXX To: National Highway Traffic Safety Administration Office of Defects Investigation (ODI) Subject: Formal Safety Defect Complaint – 2017 Hyundai Sonata Theta II Engine Failure, Excessive Oil Consumption, Intake/Engine Component Failure and Safety Hazard Dear Sir or Madam: I am submitting this formal complaint and request for immediate investigation into the dangerous and ongoing mechanical failures involving my 2017 Hyundai Sonata equipped with the Theta II engine. I believe this vehicle contains a serious manufacturing and/or engineering defect that presents a substantial safety hazard to consumers. My vehicle has experienced a pattern of progressive mechanical failure beginning with abnormal and excessive oil consumption, which appears to be directly associated with malfunctioning engine airflow and intake-related components. Specifically, the lower engine airflow system and intake functionality appear defective, placing excessive strain on the intake manifold system and contributing to cascading engine failures. As a result of these failures, the vehicle has experienced: Severe and excessive oil burning/consumption Intake manifold malfunction and abnormal operating stress Suspected overheating and/or premature head gasket failure Ignition coil failure and electrical shorting/misfires Progressive engine deterioration rendering the vehicle unsafe and unreliable Increased risk of sudden engine shutdown, stalling, fire hazard, or catastrophic engine failure while operating The vehicle has become increasingly unreliable and inoperable due to these conditions. These failures raise significant concerns regarding public safety, especially given the known history of complaints and recalls associated with Hyundai Theta II engine defects. I am deeply concerned that this vehicle may reflect a broader pattern of defective manufacturing, insufficient quality control. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

    NHTSA complaint 11742419
13. Filed May 31, 2026Failure Apr 11, 2026Grantsville, UTElectrical system, Engine, Fuel/propulsion system

    Supplemental Information to Existing NHTSA Complaint involving a 2017 Hyundai Sonata Plug-in Hybrid (VIN: [XXX] ) While traveling at approximately 70 MPH on a heavily traveled highway, the vehicle suddenly and completely lost propulsion without warning. The vehicle rapidly decelerated in traffic, creating a significant safety hazard for my family and surrounding motorists and requiring emergency maneuvering to reach the shoulder. The vehicle was towed to an authorized Hyundai dealership, where diagnostic testing identified multiple high-voltage battery system fault codes: • P0B68 • P0B6D • P0B72 The dealership diagnosed a high-voltage battery system failure requiring battery replacement. The vehicle is currently non-drivable. During my research, I found multiple owner reports involving Hyundai Sonata Hybrid and Plug-in Hybrid vehicles experiencing loss of power, hybrid system failures, limp mode conditions, and propulsion-related incidents. I also learned that Hyundai previously issued Recall 18V166000 involving 2016–2018 Sonata Plug-in Hybrid vehicles due to battery management system and voltage protection device concerns that could result in loss of power while driving. Dealer says does appply for my car. Although my vehicle’s fault codes may differ from those addressed in the recall, both involve battery-related failures capable of affecting propulsion and creating a highway safety risk. My concern extends beyond my individual vehicle. A high-voltage battery or battery management system failure that can cause a complete loss of propulsion at highway speed without warning presents a potentially serious safety risk. I respectfully request that NHTSA evaluate whether similar incidents involving Hyundai Sonata Hybrid and Plug-in Hybrid vehicles indicate a broader safety concern warranting further review. I can provide dealership diagnostic reports, repair estimates, towing records, photos, and videos upon request. Thank you for your consideration, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATI

    NHTSA complaint 11741174
14. Filed May 28, 2026Failure May 14, 2026Baltimore, MDEngine, Unknown or other

    I am writing to report a serious, premature failure of a primary emissions and safety-related component (the catalytic converter) that has occurred as a direct consequence of a known, unaddressed manufacturing defect in Hyundai's Theta II engine. My vehicle has a documented history of excessive engine oil consumption. This inherent manufacturing flaw causes the engine to burn motor oil at an extreme rate, forcing unburned oil directly into the exhaust system. Over time, this oil has fouled and destroyed the catalytic converter substrate, triggering trouble code P0420 and causing a complete component failure. A dealership inspection at Heritage Hyundai Towson (RO #XXX) confirmed "excessive wear" and failure of the catalytic converter. Because the catalytic converter is failing prematurely due to a liquid defect (excessive oil burning) rather than standard wear and tear, it poses an environmental hazard, compromises vehicle emissions control, and can lead to sudden engine stalling or reduced power while driving, presenting an active safety risk. Hyundai Motor America (Case #XXX) has formally denied assistance to rectify this consequential damage, despite full awareness of the underlying engine defect. I request that NHTSA investigate how Hyundai’s ongoing oil consumption manufacturing issues are causing cascading safety and emissions component failures in these vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

    NHTSA complaint 11740602
15. Filed May 27, 2026Failure Apr 27, 2026Pascoag, RIEngine

    The rod bearings failed in the engine. The vehicle is currently at the dealership and is available for inspection. Rod bearing failure can cause complete engine seizure while driving, creating a serious risk of losing vehicle control at any speed. This is a known issue with Hyundai's Theta II engine. Yes. The dealership performed a diagnostic on April 27, 2025 and confirmed rod bearing failure. Yes. The dealership inspected the vehicle and Hyundai corporate opened a warranty case and arranged the repair appointment, initially confirming coverage before later denying the claim without providing documentation. The dealership has also repeatedly failed to provide documentation supporting the denial of my warranty claim despite my requests beginning April 29, 2025. I have also been unable to get callbacks from the dealership after being promised updates on May 1st, May 7th, and after requesting a manager on May 18th. As of May 27, 2025 I have still not received any documentation or a callback. The check engine light came on prior to the failure. I proactively checked and changed the oil, added Lucas oil treatment, replaced the spark plugs, and replaced the battery attempting to diagnose and resolve the issue before bringing it to the dealership. No oil pressure warning light ever appeared. The check engine light persisted despite these efforts which is what led me to bring the vehicle in.

    NHTSA complaint 11740495
16. Filed May 19, 2026Failure May 5, 2026Auburn, ALElectrical system, Engine, Unknown or other

    I have a Hyundai Sonata 2017 one year after I bought the car I started having acceleration problems. I have had the throttle changed and the valve gasket cover repaired. On April 15, 2026 the check engine light came on. On April 29th I got theta 2 emissions update installed at Hyundai Auburn, Al. I took it too auto zone the same day the code P1326 was showing up and P0014. On May 5th my car entered limp mode for excessive oil leakage, I got an oil change April 6, 2026. My car has never done that until the update was installed. I get my oil changed every 6 months and also have sent them records. They denied my claim due to lack of maintenance.

    NHTSA complaint 11738867
17. Filed May 14, 2026Failure Apr 5, 2026Maricopa, AZEngine

    Engine failed while driving, Took it to dealership and the engine is seized. We were declined by Hyundai an engine replacement even though the Theta 2 engines have a lifetime replacement warranty because these engines are known to fail. They constantly deny due to 'severe owner neglect' because people do their own oil changes.

    NHTSA complaint 11737847
18. Filed May 13, 2026Failure May 4, 2026Irmo, SCEngine

    The vehicle experienced repeated engine-related failures associated with the P1326 error code, which indicates a potential engine defect. The issue first occurred around February 2023 at approximately 51,500 miles, when a warning light appeared. The problem has recurred multiple times despite inspections and service attempts. In January 2024, a dealership performed a software update related to the P1326 code. Shortly after this update, the engine began consuming excessive oil (approximately 2 liters per 1,000 miles). The condition worsened over time, and the vehicle failed an oil consumption test conducted by a dealership. The issue was confirmed by an authorized dealership, which ultimately diagnosed the engine as failed and requiring replacement in May 2026 at approximately 99,000 miles. The problem has been reproducible, with the P1326 warning code appearing multiple times over the life of the vehicle. This condition creates a significant safety risk because the engine may lose power, misfire, or stall unexpectedly while driving, increasing the risk of a crash, especially at highway speeds or in traffic. The vehicle has already experienced engine misfire and severe performance issues. Warning indicators included the P1326 error code and check engine light, which first appeared in 2023 and recurred multiple times thereafter. The engine oil consumption issue developed after the 2024 service and continued to worsen. The failed engine is currently available for inspection upon request.

    NHTSA complaint 11737552
19. Filed May 7, 2026Failure Apr 24, 2026Miami, FLEngine

    Engine experienced severe metallic knocking and loss of power. A certified Hyundai technician confirmed a FAILED Bearing Clearance Test (RO #354331). Hyundai Motor America is refusing to honor the Engine II Class Action Settlement warranty, citing internal code A99 because the vehicle was purchased at an auction, even though the title is CLEAN. This pose a safety risk of engine seizure and potential fire.

    NHTSA complaint 11736427
20. Filed May 2, 2026Failure May 2, 2026Blaine, MNEngine

    Consistent burning of oil

    NHTSA complaint 11735288