*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Engine and engine cooling
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.
Oct 24, 2026 · 180,000 milesEngine and engine cooling
The contact owns a 2017 Hyundai Sonata. The contact stated that while driving at 65 MPH, there was smoke coming from under the hood, and the vehicle lost automotive power and the vehicle was barely moving. The contact was able to drive the vehicle to the residence at a slow speed. The vehicle was taken to an independent mechanic, and the contact was informed that the engine was consuming an excessive amount of engine oil and that there was no oil in the engine. The contact stated that the vehicle had received an oil change one week prior to the failure. The dealer was contacted and made aware of the failure. The failure mileage was approximately 180,000.
Oct 21, 2026 · 180,000 milesEngine
I had recently taken my 2017 Hyundai Sonata in for an Engine Diagnostic check at the Bel Air Hyundai dealership, (10/15/26) worth $199.99 for an hour of maintenance, after experiencing sudden jolts when powering on and driving, needing additional time warming up. My initial thought was that the temperature gauge had gotten stuck again, or that the sensor needed to be fixed. I suggested that the dealership check for this issue before doing the diagnostic to see if it was still needed afterward. My service advisor, Kevin, said that this is included as part of the diagnostic testing. I figured it would be in the best interest for my vehicle to do an initial check, regardless of cost, to avoid…
Oct 15, 2026Power train
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.
Oct 1, 2026Engine
I am reporting an unaddressed, critical safety defect involving the Theta II engine in my 2017 Hyundai Sonata. The engine has developed a severe internal metallic knocking noise consistent with connecting rod bearing failureâthe exact manufacturing defect associated with Hyundai's major engine recall campaigns (such as Recall 198 / Campaign 966)
Aug 28, 2026Unknown or other
I was driving down the road when my sunroof glass completely ripped away from the top and flew off. The glass is gone but the frame is still there but bent. I took it to a auto glass repair shop that stated "sunroof glass separated from urethane, came off and bent frame." I am dropping off at Hyundai dealership 9.17.26 to have them inspect. My insurance will not cover repairs. So I am hoping maybe this has happened to other people. There was a recall on sunroofs for the 2014-2016 Hyundai Sonata's NHTSA campaign 16V726000 A bonding issue with the front sunroof wind deflector anchor plate can cause the deflector to come loose and jam the glass panel when closing, or detach entirely while the…
Sep 9, 2026Engine
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…
Jan 1, 2026Engine
We had a recall done, Campaign 92C, and every since then the car drives horrible. It's worse when cool, it sputters, and hesitates especially when excellerating. Even after warmed up it seems to slam in and out of gear at low speeds, even when foot is not on the gas. The drive is choppy. The dealership told us to drive it and let the transmission "learn" our driving patterns, but it has not resolved itself. Before campaign car ran smooth, now shuttering and sputtering.
Jun 11, 2026
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.
