Which parts fail
Components named in complaints (fuel pump, injectors, fuel tank, hybrid and EV propulsion).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2016 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2016 Hyundai Sonata. The contact stated that while driving approximately 60 MPH, the vehicle suddenly shut off with the message "HEV System Failure" displayed. The driver safely pulled over to the side of the road and restarted the vehicle. A towing truck arrived on the scene and reset the diagnostic codes before towing the vehicle. The vehicle was towed to the local dealer. The dealer retrieved several diagnostic trouble codes; however, the dealer was unable to determine the cause of the failure. The vehicle was test-driven but the failure was not duplicated. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 149,000.
2016 Hyundai Sonata (not part of any recall) driven short distance on expressway had "check engine light" come on. Pulled off of expressway and checked under hood...No visible issues. Chose to return home via side streets as car was riding rough and having problems with acceleration at that point. Short while later, heard loud noise and saw smoke coming from under hood. Pulled to the side of the road and exited car. Was told by bystander that car was on fire. Called Fire Dept, by the time of their arrival, entire front end ablaze, tires and body melted. Thankfully, fire extinguished before any explosion or damage to neighbor's property occurred. Vehicle was a total loss.
The contact owns a 2016 Hyundai Sonata. The contact stated that the vehicle failed to start. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed that the engine had failed. The vehicle was repaired; however, the failure recurred. The vehicle was taken back to the dealer, where it was diagnosed that the high-pressure fuel pump had failed. The contact related the failure to an unknown Hyundai Extended Warranty that had expired. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was 98,000.
We were told from Tulsa Hyundai that our car was involved in a massive recall due to engine failure and that the warranty had been extended to 150,000 miles on Theta engines. They told us we had to follow the process in order to have a claim submitted to Hyundai corporate. They required us to pay for a valve gasket replacement and a valve cover gasket ($1000), then to take the car home and drive for 1000 miles and then bring it back in. We brought it back in and were required to pay for a combustion cleaning (around $800) and then take it home and drive it for 1000 miles. We brought it back in and they performed the oil consumption test. They then submitted the claim to Hyundai and we heard back the next day (9/18/2024) that they were denying they claim due to it being an issue with piston rings instead of rod bearing failure. …
I was driving a 2016 Hyundai Sonata on a mountain highway and it started to run rough and lose power dramatically when accelerating. A dangerous situation on a steep curvy highway that has many one lane sections. Shortly thereafter a dash light came on. There was no warnings or dash lights or symptoms prior to this incident. I took the vehicle to a mechanic and ran the code. It said there was a misfire in cylinder 3. Replaced the ignition coil and spark plug for cylinder 3 and it did not fix the problem. The mechanic then pulled the motor to check the valves. Valve 3 was burnt, had a hole and stuck open. The car had approximately 75,180 miles. Well within the warranty time frame of 10yrs or 100,000 miles for an original purchaser. The mechanic had the valve machined, and replaced the head gasket and reassembled the the motor. I picked the car up and drove it home. …
The problem with my vehicle is a failure of internal engine components, specifically a known defect in the piston rings of the Hyundai Theta II engine. This failure causes excessive oil consumption, which is burned internally. The internal engine components have failed, leading to a widely documented defect in the Hyundai Theta II engine. The primary symptom, which began to get serious around 80,000 miles, is the constant need to add oil to the engine every two weeks. If I do not do this, the low oil warning light illuminates on the dashboard, serving as a continuous alert of the problem. This failure was officially confirmed by an authorized Hyundai dealership. About two weeks ago, they first documented that there were no external leaks on the vehicle. …
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. …
My 2016 Hyundai Sonata (VIN: [redacted]) 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 [redacted]. As of [redacted] Hyundai has not responded to any of my Executive Office or Regional escalations. …
I have been going to the dealership since July as my engine light was not shutting off. I kept being told that there were no loaner cars and that they could not fix the problems I was having kept putting a band aide on the issue and saying that I would have more problems. They told me the cat converter would need to be replaced but it was an engine recall issue. They had a loaner car for me for one day told me it was fine that it would probably go again I had them check the car again and they filled the oil and sent me on my way. Now I was on the side of the road with no car and am now being told they can't work on my car until March which since I have been seeing them for 4 months now for the same problem that just got worse you would think they would try to help me. Instead they told me to go somewhere else turn in my dead car or I have to tow it and then tow it back in March. …
My 2016 Hyundai Sonata started using and leaking oil in August 2023 when it had about 129,000 miles and when you tried to go faster than 55 miles per hr. it would not accelerate. We feel there is a danger to drive it in traffic. We took it to the dealership in Pensacola, FL. They found a valve cover gasket had multiple leaks which they replaced. Found a code P1326 (whatever that means), Performed T3G campaign and followed a flow chart and BCT test passed. Don't know that any of this addressed the fact that the motor won't accelerate. Charged me $3,000 for something. Car ran okay for a while and started doing the same thing again. In June of 2024, took it to local mechanic who ran diagnostics and replaced a coil and plugs which cost another $600. …
Fuel System complaints in other Sonata years
Frequently asked questions
How common are fuel system problems on the 2016 Hyundai Sonata?
NHTSA has 35 complaints about the fuel & propulsion system of the 2016 Hyundai Sonata, 5% of the model year's 727 complaints. The component named most often is delivery › fuel pump (1 mentions).
Is there a recall for 2016 Hyundai Sonata fuel system problems?
No. NHTSA lists no fuel & propulsion system recall for the 2016 Hyundai Sonata, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2016 Hyundai Sonata fuel system problems start?
Half of the complaints with a recorded mileage happened before about 70,000 miles, and 9% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 1 fire and 0 injuries to fuel & propulsion system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.