Hyundai
Sonata

Car started misfiring while driving and engine light came on. It kept losing power but I was able to pull off highway. This put myself and others in danger because speed was significantly reduced suddenly. Dealer said problem was due to oil leaking on spark plugs. The car had been using excessive oil. Dealer said this is known issue but I had to pay for any repairs since I was the second owner. Hyundai still pays for the original owner to get an oil consumption cleaning, but recently stopped paying for secondary owners. If the oil consumption cleaning does not work, then the next step is to replace engine, paid by customer if Hyundai refuses. Mileage on car is 75,769.

I am submitting a formal complaint regarding ongoing and severe engine issues with my 2018 Hyundai Sonata SE. Despite proper maintenance, the vehicle has developed extreme oil consumption and misfire problems that have made the car unreliable, unsafe, and financially burdensome. Beginning around 118,000 miles, the vehicle started consuming oil so rapidly that I was forced to completely replace the oil every 1–2 weeks because it would run dangerously low or nearly empty. This level of oil loss is not normal, acceptable, or sustainable. I have detailed documentation, receipts, mileage logs, and maintenance history supporting this. In addition to oil consumption, the vehicle has repeatedly misfired, produced diagnostic trouble codes, and fouled spark plugs with oil. I have been forced to replace spark plugs approximately every two weeks, which is clearly abnormal for any modern vehicle. On multiple occasions, the vehicle has experienced violent knocking noises, severe loss of power, hesitation during acceleration, and near-stalling. One incident was so loud and aggressive that it felt like the engine was going to come out of the hood. These symptoms pose a serious safety risk while driving. I brought the car to a Hyundai dealership at approximately 118,000 miles for an oil-consumption test. The vehicle failed that test, clearly confirming excessive oil consumption. Despite this, Hyundai refused to provide repair, internal engine cleaning, or engine replacement, claiming the vehicle was already over 100,000 miles I have maintained this vehicle responsibly and have documentation of regular oil changes, spark-plug replacements, inspections, and diagnostic reports. Despite my efforts, the issue continues to worsen, and the vehicle remains unsafe and unreliable. This ongoing problem has caused significant financial strain, emotional stress, lost time, and fear of engine failure while driving. Based on countless similar complaints from other Hyundai owners, this appear

See attached document for complaint.

My 2018 Hyundai Sonata’s oil light flashed briefly while driving, so I checked the oil level and found the dipstick completely dry. The car has been maintained regularly and was still about 1,000 miles away from its next scheduled oil change. There are no visible leaks, and the engine is not smoking. I had to immediately add oil to prevent engine damage. This appears to be a case of excessive oil consumption, which I have since learned is common in Hyundai Sonatas with this engine. I am very concerned that low oil pressure could cause engine failure or sudden loss of power while driving, creating a serious safety hazard. I request that NHTSA investigate this issue for 2018 Sonatas, as many owners are reporting similar experiences, and Hyundai has issued a Technical Service Bulletin (TSB 23-EM-008H) about excessive oil consumption but no recall.

During multiple dealership visits in 2025, my 2018 Hyundai Sonata Limited 2.0T was repeatedly returned in unsafe condition. Southern Hyundai installed both front CV axles and torqued them incorrectly. The right axle was later confirmed under-torqued by about 50 ft-lbs, and the left axle was later found over-torqued 40ft-lbs Priority Hyundai later identified and corrected the under-torqued right axle, which briefly improved symptoms but did not resolve the underlying issue. When I returned for a follow-up on October 29, 2025, for a documentation-only appointment due to an active corporate case, the dealer ignored my instructions and altered evidence by loosening and re-torquing the left axle nut without consent. They recorded the torque at 250 ft-lbs in the repair order but failed to capture the required photos or before/after readings and referenced the wrong vehicle’s torque specification (Hyundai Elantra) in the documentation. Since then, the vehicle has continued to show steering pull, vibration, and instability at speed. Several visits showed only 0–3 miles of verification driving after safety-critical repairs involving brakes, suspension, and driveline components. Aftermarket parts were installed when OEM parts were promised, and uneven tire wear developed quickly. Safety risks include wheel-bearing damage, steering loss, and driveline separation due to repeated improper torque and altered evidence. Independent Firestone and Honda technicians have verified these issues. The matter remains under active Hyundai Corporate Case #[XXX]. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Unknown. 2018 Hyundai Sonata engine has failed. Only purchased the vehicle in December 2024, and the engine is defective. There is much information, via research, indicating that Hyundai is aware of the engine issues with this year vehicle, but are unwilling to make amends. Vehicle has 100,189 miles.

Engine consumes oil, more than 1 quart a week. started misfiring on a trip and dealer stated that engine needs to be replaced since valve was burnt. have 116k miles on car and have been diligent in maintenance.

THE HEADLIGHT LOW BEAMS ARE DANGEROUS AND NEED TO BE RECALLED ASAP? After his death, I acquired this vehicle from my father who had stopped driving at night thinking he had developed a vision issue. The first time I drove it at night I discovered the low beams are defective, and that was the problem, not my dear old Dad’s vision. The light emitted does not extend far enough in front of the vehicle to light a large enough safe distance. There are also large black areas at the far edge of each light that float from side to side with the beam while making turns. This also causes the areas on one side or the other to loose lighting. While turning they are often facing the wrong direction making it virtually impossible to see the unlit areas. We live in the country down a 20 mile long two lane road with many turns and minimal lighting compared to city driving. We then turn onto a 3 mile very narrow road with numerous turn, minimal shoulders, and a double hairpin turn with a dip at the end. It required us to leave the high beams on at all times even when other vehicles are approaching because it would be too dangerous to only use the low beams. When I took it to the dealer they ignored the problem. I then insisted they examine them immediately—since that was my #1 PRIORITY when I dropped it off for inspection during a regular service. Their conclusion was that there was nothing they could do to fix it. THAT IS AN UNACCEPTABLE RESPONSE! THOSE LOW BEAM LIGHTS ARE EXTREMELY DANGEROUS. My research has found that this has been an issue since the vehicle was first made and when purchased by my dear old Dad, his only way of dealing with it was to stop driving at night.