2017 Hyundai Sonata power train problems

“I had my engine replaced under the Theta Engine lawsuit and I was due for the 9C2 service campaign and it was installed...ever since I picked up my car it shifts weird between 1st and 2nd. I brought it back to a different Hyundai dealer as the warranty work was done at another location and they recommended a transmission flush and relearn. They can feel it slipping and the other dealership noted no problems, which leads me to believe it was because of the service campaign. I also called corporate and the customer service rep had heard of this before as well as a bunch of forums online.”

“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,…”

“[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…”

“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.”

“Airbags did not deploy no indicator light came on before nor after I was struck from my driver side front area and yes it is available for inspection upon request. My safety along with my sisters safety was put at risk due to the negligence and cheapness of the dealership I purchased the car from also from there misleading information and improper inspection before selling me the car Car has not been reproduced or confirmed The car was inspected by a third party appraisal company for damages amounts There were no lights on at all before the accident and I am pretty certain that the dealership cleaared the codes before selling me the car”

“e vehicle is burning approximately 2 quarts of oil every month with no external leaks. This indicates severe internal oil consumption, which is a known defect in Hyundai’s Theta II 2.4 GDI engines. I discovered oil inside the VVT solenoid electrical connector and on other wiring, which shows oil is traveling through the engine harness. This causes hesitation, rough running, and the risk of sudden engine power loss. The vehicle feels unsafe to drive because the oil level drops quickly, and the engine could seize or stall while driving. Hyundai vehicles of this generation have a history of excessive oil consumption, piston ring failures, and engine fires, and I believe my vehicle is experiencing the same defect. This is a serious safety concern.”