2017 Hyundai Sonata: engine failure

Filed Oct 26, 2026 · Engine · 180,000 miles · FL

The contact owns a 2017 Hyundai Sonata. The contact stated that while driving at 65 MPH, there was an abnormal sound coming from the vehicle with the check engine warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with engine failure. The contact was informed that the engine was consuming oil. The contact referenced an unknown recall; however, the VIN was not under recall. The contact was informed to take the vehicle to the dealer for assistance. The failure mileage was approximately 180,000.

Filed Sep 4, 2026 · Engine · UT

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.

Filed Jun 22, 2026 · Electrical, Engine · CA

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 the federal safety agency 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 the federal safety agency 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)

Filed Jun 6, 2026 · Engine, Suspension · PA

[XXX] [XXX] [XXX]; [XXX] [XXX] [XXX] Date: XXX To: the federal safety agency 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)

Filed May 14, 2026 · Engine · AZ

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.

Filed Apr 30, 2026 · Engine · TX

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.

Filed Mar 21, 2026 · Engine · TX

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

Filed Mar 13, 2026 · Engine · 95,000 miles · NY

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.

Filed Jan 24, 2026 · Engine · AZ

My 2017 Hyundai Sonata is exhibiting a severe metallic knocking noise and metal debris in the engine oil—primary indicators of the Theta II engine defect (the federal safety agency Campaign 17V578). These symptoms indicate imminent engine failure, posing a significant stall and crash risk. On or around 8/20/25, I took the vehicle to Earnhardt Hyundai-San Tan. I informed the technician of the oil burning and metal shavings. They refused to perform the recall repair and charged a $200 diagnostic fee for an inspection related to a federally mandated safety recall. Under federal law (49 U.S.C. Chapter 301), recall remedies must be provided at no cost to the owner. Furthermore, components were not reassembled correctly during the inspection. The vehicle is now leaking oil onto my driveway and has been rendered inoperable. It has not been driven since I picked it up on August 25, 2025. I am requesting that Hyundai be compelled to perform the recall remedy and reimburse the unauthorized diagnostic fee.

Filed Jan 19, 2026 · Engine, Transmission · VA

My vehicle has a documented excessive oil‑consumption defect. After a 1,000‑mile oil‑consumption test performed by a Hyundai dealership, the engine was found to have consumed 2.8 quarts of oil, which is far above normal and poses a safety risk. The dealer referenced TSB 23‑EM‑008H and recommended a chamber cleaning but could not guarantee it would resolve the issue. Hyundai Motor America declined to cover the repair and refused to escalate my case. This level of oil consumption is consistent with known Theta II engine defects that have led to engine seizure, stalling, and fire in other vehicles. I am reporting this as a safety concern due to the risk of sudden engine failure while driving.

Filed Jan 10, 2026 · Engine · CA

Manufacturer has refused engine replacement under federal KSDS recall settlement without providing causation proof. Owner has maintenance records. Request the federal safety agency compliance review.

Filed Jan 8, 2026 · Engine · CA

Manufacturer is refusing recall engine replacement alleging neglect without proof of causation. Vehicle has documented maintenance. Denial appears improper under recall compliance law.