2016 Hyundai Sonata fuel/propulsion system problems

“My 2016 Hyundai Sonata (VIN: [XXX]) has a serious safety issue involving excessive engine oil consumption. The vehicle loses oil rapidly between changes and requires frequent top‑offs to avoid engine damage. This creates a risk of sudden engine failure while driving. The dealership, South Charlotte Hyundai (10518 Cadillac Street, Pineville, NC 28134), refused to perform Hyundai’s official oil‑consumption test. Instead, they told me to pay $750 for a combustion cleaning and stated it would not fix the underlying problem. They would not document the refusal or provide any testing. I contacted Hyundai Corporate multiple times: • May 21, 2026 – Executive Office complaint submitted • June 3, 2026 – Follow‑up sent • June 29, 2026 – Regional escalation sent My Hyundai case number is XXX. As of XXX Hyundai has not responded to any of my Executive Office or Regional escalations. Only Customer Care replied with a template denial and no investigation. I have been waiting over two months with no action from Hyundai Corporate. I am reporting this because the manufacturer has not addressed a safety‑related defect, the dealership refused required testing, and the vehicle…”

“I am writing about my concerns on a 2016 Hyundai Sonata SE that I purchased for my daughter in October 2023. After purchasing I took it to my local Hyundai dealer to have it checked out. It was one of the cars that came with a lifetime warranty for the rods DO TO A DEFECT.On January 2024 my daughter was driving on the freeway when all of a sudden it just stopped accelerating and when checked it was a Knock sensor detection system. The dealer took it in and inspected and said it was a defective sensor and replaced it.This made me uncomfortable as I felt the sensor did its job and it was just a matter of time before the rod blew through.During the next few months it became very apparent that the car was going through unbelievable amounts of oil.It had a ticking so we replaced all the spark plugs and noticed oil saturating the plugs and realized a leak in the valve cover gasket which was also replaced.We thought this might be the cause but no oil was on the ground and nowhere on the engine.I just thought it was burning oil but no indicator lights were going off. The car could have no oil and it would not let us know. She's lucky to drive 300 miles a month.She has…”

“I have a car covered by the Theta II Settlement. Engine, fuel system. Metal shavings found in oil and oil is diluted with fuel and oil if overfilled 1 inch above full mark on dipstick upon pickup from dealership. The vehicle is available for inspection at my residence; however, it is currently grounded as a known safety hazard. The vehicle is exhibiting symptoms of imminent engine failure (audible knocking, P0011 code, and oil dilution). Despite being shown evidence of this(photo and video of oil overfill and watery viscosity) , the manufacturer instructed me to continue operating the vehicle, placing myself, and other drivers at risk of a high-speed collision or vehicle fire. The symptoms (P0011 code and engine noise) were confirmed by an independent mechanic on March 25th 2026. However, during the official Bearing Clearance Test (BCT), the dealership intentionally overfilled the engine oil by 3 quarts (documented via photograph) to muffle mechanical noise and artificially pass the diagnostic and issued a pass on all inspections despite the oil hazard. Hyundai Corporate Case Manager Nikulmar Dhabi has admitted on record that the dealer was out of compliance by…”

“This complaint is NOT related to the existing recall associated with this vehicle. The vehicle is experiencing a serious loss of power and acceleration issue. The car is unable to accelerate past approximately 60 mph. When pressing the accelerator fully, the vehicle does not respond or increase speed. While attempting to accelerate, the engine RPM increases and then suddenly drops repeatedly, causing the vehicle to struggle to maintain speed. This behavior is consistent and occurs during normal driving conditions. This creates a dangerous situation, especially when merging onto highways or attempting to accelerate in traffic, as the vehicle cannot respond when needed. The issue has occurred multiple times and makes the vehicle unsafe and unreliable to operate.”

“My 2016 Hyundai Sonata (2.0T/2.4L engine) has been experiencing loss of motive power and severe engine stumbling at stoplights, creating an unreasonable risk of a crash in traffic. The Check Engine light is on with DTC P0010. Upon inspection, the internal oil seal plug at the intake camshaft E-CVVT has become unseated, causing an active oil leak. This matches the exact defect and symptoms (elevated idle of 1,200–1,400 RPM and power reduction) described in Hyundai Service Campaign TX3 (TSB 15-01-022-1). While that campaign only applied to 2015 models, my 2016 vehicle has suffered the identical failure. I am requesting that this safety-related defect be investigated for 2016 models to prevent potential engine fires from oil leaks or accidents from sudden power loss”

“This vehicle has experienced multiple hybrid system failures while driving, including a complete loss of power “Hybrid System Warning – Turn Engine Off” on the interstate in June 2022 through November 2025. These events have placed me and my loved ones in dangerous driving situations. Despite a warranty‑covered engine replacement at 82,015 miles (January 2023), the same hybrid system issues have recurred. Hyundai initially indicated a warranty claim was submitted, then told me there was no record of any claim in the system. The dealership claims it was denied — creating a serious inconsistency in communication and accountability. In addition, I have identified multiple NHTSA complaints in the database from other owners of 2016 Sonata Hybrids (VINs beginning with KMHE) describing similar highway shutdowns and hybrid system failures, which raise concern about a broader, unaddressed safety defect not currently covered by existing TSB or recall actions. I am respectfully requesting: A regional inspection and review of my vehicle prior to any further work. A review of Hyundai’s handling of this warranty claim and the discrepancy between dealer and corporate…”