Hyundai Sonata Complaints (2017)

881 consumer complaints on file.

#11740602May 28, 2026
ENGINE, 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)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740495May 27, 2026
ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11738867May 19, 2026
ENGINE, UNKNOWN OR OTHER, ELECTRICAL SYSTEM
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11737847May 14, 2026
ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11737552May 13, 2026
ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11737182May 11, 2026
ELECTRICAL SYSTEM
On 12/20/25, the car - a Sonata plug-in hybrid - failed to start. When I pushed the "start" button, the dashboard display lit up w many clearly irrelevant error messages. Each time I pressed start, somewhat fewer error messages blasted toward me, and finally, no response at all. On 12/21/2026, the tow driver said it was the 12-volt battery. He gave us a jump start and we drove a few blocks. However, it failed at the turn lane while waiting for the light to turn. We turned it back on, bought a new battery, had it installed. On 12/29/25, my husband was driving. He turned into the intersection with a traffic light. As he was making the turn, the car simply quit. No warning. The car was dead, and blocking traffic! He pressed the start button to turn off the car, then again to turn it on. He was able to complete the turn and parked on the side of the road. By this time it had a "check engine" light on. He then drove slowly the few blocks back to our house. On 12/30/2025, the car was towed to a local mechanic. He said it threw the code PODE7, "almost certainly for a failed High Voltage battery." It was still under warranty, and we had the car towed to the dealership. After keeping it for 2 or 3 weeks, they confirmed the code and that the control panel needed to be replaced. We finally picked up the car (w new control panel) on 2/20/2026. In the meanwhile, we looked up Hyundai control panel repairs on a reddit forum. We found lots of chatter about it. Turns out it's a recognized problem in Sonata and Ioniq EV and PHEV's! Clearly, a car failing in the middle of an intersection, highway, etc is a safety problem and needs to have repair/replacements made BEFORE THEY HAPPEN!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11736427May 7, 2026
ENGINE
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11735288May 2, 2026
ENGINE
Consistent burning of oil
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11735000April 30, 2026
ENGINE
The failed component is the engine assembly in my 2017 Hyundai Sonata SE with the 2.4L Theta II GDI engine. The failure involves excessive oil consumption and internal engine failure, specifically suspected piston ring deterioration allowing oil to pass into the combustion chambers. The vehicle is available for inspection upon request. Safety was put at risk because the engine was losing oil rapidly. If the oil level drops too low, the engine can seize, stall, or lose power while driving. Sudden engine failure at road or highway speeds could increase the risk of a crash. The issue required constant oil monitoring and made the vehicle unsafe to rely on. The problem was confirmed by both an independent repair shop and a Hyundai dealership. At about 99,813 miles, an independent shop diagnosed oil burning from the tailpipe. I then paid for major repairs, including cylinder head and valve work, but the oil consumption continued. A later independent inspection found internal oil consumption consistent with failed piston rings and oil bypassing into the combustion chambers. The Hyundai dealership performed Hyundai’s oil consumption testing process, including combustion chamber cleaning and rechecking oil level. The vehicle failed and engine replacement was approved. The dealer quoted $11,400-$12,000 for replacement. The vehicle has been inspected by an independent repair facility, a Hyundai dealership, and reviewed by Hyundai Motor America Customer Care under case number 42489659. Hyundai denied assistance, stating the vehicle is outside warranty due to time and mileage. Symptoms first appeared around 99,813 miles and included excessive oil consumption, burning oil from the tailpipe, reduced power/dragging, abnormal rattle/noise during low-speed acceleration, and poor fuel economy. After repairs, the oil level still dropped below minimum quickly. I am filing this complaint because this condition may cause sudden engine damage, stalling, or loss of power while driving.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11734703April 29, 2026
ENGINE, UNKNOWN OR OTHER
I am reporting a serious safety issue involving a 2017 Hyundai Sonata Plug-in Hybrid (VIN: [XXX] ), originally purchased in California. While driving at approximately 70 mph on a highway, the vehicle suddenly lost all propulsion without warning and rapidly decelerated. This created a dangerous situation with surrounding traffic and put me and my family at risk. I had to quickly maneuver to the shoulder to avoid a potential collision. The vehicle was towed to an authorized Hyundai dealership in Utah, where it was diagnosed with a failure of the high-voltage battery system. I was informed that the battery requires replacement. This type of sudden loss of propulsion at highway speed is extremely hazardous and could result in a crash, injury, or fatality. There were no prior warnings indicating an imminent failure of this severity. Given the safety risk associated with unexpected loss of propulsion, I am concerned this may represent a broader issue affecting similar vehicles. The vehicle is equipped with an interior camera, and video of the incident can be provided if needed. I respectfully request that this issue be investigated as a potential safety defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11733236April 23, 2026
ENGINE AND ENGINE COOLING
See attached document for complaint.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11732386April 20, 2026
ENGINE
Burns through oil Oil will be black and barely any on the dip stick Cannot make it to recommended oil change miles or date Goes into limp mode
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11731393April 15, 2026
ENGINE
2/25/2026 vehicle was put in service for a safety warranty recall. 2/26/2026 Hyundai approved the replacement of the engine, but there were costs involved that I was responsible for (approx. $800). 3/9/2026 I was informed by Hyundai the vehicle was complete, and would now last "for another 200,000 miles". I picked up the vehicle and only drove 5+ miles from the dealership when the vehicle’s motor completely shut down, putting me in a VERY UNSAFE driving condition, almost causing a serious accident. Vehicle was returned to Hyundai the same day and I was informed they were still figuring out the failure and to be patient. 3/11/2026 Hyundai informed the vehicle would now need a new catalytic converter and O2 sensor, and that it would all be covered under warranty. On 3/12/2026 Hyundai informed me that they would not fully cover the cost of the new parts and I ended up paying another $1300. 3/19/2026 Hyundai notified me that the vehicle service was complete, and the vehicle was ready for pick-up. I picked up the vehicle that day and again only drove 5+ miles when the vehicle repeated the same failure with the motor completely shutting down and again putting me in a VERY UNSAFE driving condition and almost causing a serious accident. Vehicle returned to Hyundai the same day. 3/23/2026 was told I would receive update once technician gets to the vehicle. 3/26/2026 informed that the vehicles Brake Booster Actuator needed replaced, and I have to cover the almost $4000 to replace this part and later informed Dealerships GM was covering cost. 4/8/2026 vehicle being worked on and completed by the end of that day. 4/9/2026 vehicle failed a 3rd time with same codes and limp mode. Tech line stating to replace EGR valve and Intake Manifold. 4/13/2026 informed that Hyundai refused to pay total amount, but were going to re-submit to not be completely out of pocket. 4/15/2026 vehicle has now been in Service for 7 weeks for a Safety Warranty recall.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11729105April 3, 2026
ENGINE
I am submitting a vehicle safety complaint regarding a recurring HEV warning system indicator affecting my 2017 Hyundai Sonata Hybrid that was not properly diagnosed despite multiple service visits to Nalley Hyundai beginning around July or August 2022. During several service visits while the vehicle remained covered under an extended warranty, I reported the HEV warning indicator to the dealership. Each time the vehicle was returned to me, the warning light was no longer illuminated, giving the appearance that the issue had been resolved. I was not billed for these visits. However, I was informed that the dealership could not determine the cause of the warning indicator, and no permanent repair solution was completed. Because this issue involves the hybrid electric system, I am concerned this may represent a safety-related condition affecting vehicle reliability and drivability. The warning indicator has continued intermittently and has now progressed to the point that my vehicle is no longer dependable transportation. I respectfully request that this complaint be reviewed as a potential hybrid system warning indicator concern affecting the 2017 Hyundai Sonata Hybrid.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11727305March 26, 2026
SEAT BELTS
The contact owns a 2017 Hyundai Sonata. The contact stated that the front driver’s side seat belt failed to lock securely. The contact stated that the seat belt loosened unexpectedly and failed to properly protect the driver while operating the vehicle. The dealer was notified of the failure. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 102,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725990March 21, 2026
ENGINE
Care recently became inoperable. The engine was knocking, then stalling and then inoperable. Checked Hyundai website to find Engine Recall describing exactly what my Hyundai was/is experiencing. I brought vehicle to Clay Cooley dealership (39444 Lyndon B Johnson Fwy, 75232) and explained that I see the recall on the Hyundai website describing what my vehicle is experiencing. After their service mechanics review, the Service Department Representative falsely accusing me of the engine failure, stating that I "must not have changed my oil regularly". According to the service department, my 2017 Hyundai Sonata (132,000 miles) is not covered in the engine recall, and I must pay $4,926.53 for the repair. cc: FTC - ReportFraud.ftc.gov Texas Attorney General - Consumer-Protection/file-consumer-complaint
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11725213March 18, 2026
POWER TRAIN, ENGINE
To the National Highway Traffic Safety Administration, I am filing this formal safety complaint regarding a dangerous engine failure incident involving my 2017 Hyundai Sonata Plug-in Hybrid. Description of Incident: While traveling on CA-85 near Mountain View, California, at approximately 65 miles per hour, the engine suddenly and without warning lost all power. The vehicle began to slow down involuntarily in active highway traffic, creating an immediate and serious risk of rear-end collision. The driver had no ability to maintain safe highway speed or accelerate out of danger. The vehicle had to be towed from the scene to the dealership. There was no warning light or prior indication that engine failure was imminent. The failure was sudden, complete, and occurred at highway speed in heavy traffic conditions. Safety Risk to the Public: This incident represents a significant and ongoing public safety hazard. A sudden, unpredictable loss of engine power at highway speed — with no prior warning — places the driver, passengers, and surrounding vehicles at serious risk of collision. This is not an isolated mechanical inconvenience; it is a life-threatening failure mode. Known and Documented Defects: The 2017 Hyundai Sonata Plug-in Hybrid has been the subject of multiple recalls and class action litigation related to engine defects. My incident is consistent with the known failure patterns documented in those proceedings. Despite this history, Hyundai Motor America has denied my warranty claim, citing missed services — a characterization I dispute, as the vehicle was serviced exclusively at an authorized Hyundai dealership whenever the onboard system indicated service was due, and no technician ever identified or disclosed any engine damage during those visits. Request to NHTSA: I respectfully request that NHTSA: 1. Open or expand an investigation into engine failure incidents in the 2018 Hyundai Sonata Plug-in Hybrid 2. Investigate whether a recall is warranted
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11724054March 13, 2026
ENGINE
The contact owns a 2017 Hyundai Sonata. The contact stated that while his wife was driving at an undisclosed speed, the vehicle experienced engine failure. The vehicle made a knocking sound prior to the failure. No warning lights were illuminated. The vehicle was towed to the residence and eventually towed to the dealer, but was not diagnosed or repaired. The dealer acknowledged the engine failure and that the failure was a common failure. The dealer declined the repair due to a lack of service records. The contact was offered a combustion cleaning; however, the vehicle was disabled. The manufacturer was notified of the failure. The approximate failure mileage was 95,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11722532March 6, 2026
ENGINE
The contact owns a 2017 Hyundai Sonata. The contact stated that the vehicle had experienced excessive oil consumption, caused by engine rod bearing failure. The engine rod bearing failure caused excessive oil consumption and premature spark plug fouling, requiring the frequent replacement of the spark plugs. The dealer was notified of the failure. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 132,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11720516February 25, 2026
UNKNOWN OR OTHER
Sun roof flew off while driving, the metal framing was twisted and dent. Sun Roof was closed at the time. Pictures were sent to insurance company but no one has looked at it yet. No warning. Sun roof was working properly.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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