While starting and accelerating my 2018 Hyundai Tucson, I began hearing abnormal engine knocking and noticed rough performance. I took the vehicle to an authorized Hyundai dealership, where they diagnosed an internal engine defect. They confirmed the engine issue but refused to cover the repair, citing that Iam not the original ownera”despite public information stating that Hyundaias extended engine defect warranty (related to known bearing failures) applies to all owners for up to 15 years/150,000 miles. This creates a major safety concern, as I drive long distances on highways daily and fear the engine may seize or fail at high speeds. The vehicle remains at the dealership and is currently undrivable. Iave submitted proper maintenance records, and the issue has been escalated through Hyundai Consumer Affairs and the Better Business Bureau. This appears to be a widely reported engine defect that Hyundai is not consistently addressing. The lack of coverage and delay in resolution places drivers at unnecessary risk.