Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2020 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2020 Hyundai Sonata. The contact stated that the fuel failed to go into the tank. The seat failed to move. The engine light illuminated. The vehicle stalled. While driving, the fuel gauge went from full to empty. The contact received the NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline) after the failure. The vehicle was towed to the local where it was diagnosed that the fuel tank had expanded. The vehicle was repaired approximately eight months later. The contact called another local dealer. Ourisman Hyundai Bowie, 2404 Crain Hwy A, Bowie, MD 20716, who was unable to schedule an appointment. The manufacturer instructed the dealer to keep the vehicle due to it being a fire risk. The manufacturer was contacted regarding a buyback. The failure mileage was approximately 80,000.
The contact owns a 2020 Hyundai Sonata. The contact stated while driving at an undisclosed speed, there was an abnormal gasoline odor inside the vehicle. The contact then heard a loud pop and pulled over to the shoulder of the roadway. After a visual inspection, the contact observed gasoline leaking from the fuel tank filler neck, even though the access door and gas cap were both securely closed. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the canister purge valve, causing the fuel tank to swell, resulting in damages to the fuel pump. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 47,000.
The contact owns a 2020 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, there was an abnormal gasoline odor inside the vehicle, after which the vehicle lost motive power. The contact pulled over to the shoulder of the roadway, moved the rear seat, and observed that the fuel pump was protruding upwards. The check engine warning light was illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the purge valve, resulting in damages to the fuel pump and fuel tank. The vehicle was repaired, but the failure reoccurred. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 47,000.
The contact owns a 2020 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the low oil warning light illuminated. The contact added oil to the engine. The dealer was made aware of the failure. The vehicle was taken to the dealer several times, and several oil consumption tests were performed. The contact was informed that the oil consumption test results did not indicate excessive oil consumption. The failure reoccurred. The vehicle was taken to the dealer, and the contact was informed that the oil level was a half quart low. The contact was informed that no repair options were available. The manufacturer was not made aware of the failure. The failure mileage was approximately 80,000.
While stopping at a major highway intersection on [redacted] for a red light vehicle stalls and will not start back up while everyone else continues at a 55 mph mile an hour passing me on each side! This happened more than 6 times . While you're stuck in intersection,you have to keep trying to start the car eventually it will start . Apparently it is EGR valve and is a very common problem. IT IS NOTED IN THE common problem for this year making model and the repair cost is in the range of $1600 even the dealership said it is a very common problem. They have been experiencing it.
The contact owns a 2020 Hyundai Sonata. The contact stated that the vehicle hesitated while depressing the accelerator pedal, with the check engine warning light illuminated on the instrument panel. The vehicle was taken to several independent mechanics and dealers to be diagnosed; however, the cause of the failure was not determined. The contact stated that one mechanic replaced an unknown sensor, but the failure returned soon after the repair. The manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 101,000
It was smoking from the engine, I immediately stopped the vehicle. My safety was put at risk immediately while being in the vehicle when the air bags deployed hitting me in the face and causing my face to swell. The safety of others was put at risk due to others being right next to me and putting others at risk of engine blowing up. Yes, the vehicle has been inspected by police. There were no warning signs on the vehicle.
In May of 2023 my check engine light came on. Took the car to the dealer and the diagnosis was that the egr cooler was the culprit so they replaced it and everything was fine until 12/21/2023. I am driving on the highway and suddenly I hear a loud alarm and upon checking my instrument cluster I see a warning for engine overheating, the heat was on but suddenly the smell of something burning covered the entire cabin of the vehicle. I had to pull over to the side in the middle of a busy highway in freezing conditions and shut my engine down to avoid further damage. I believe the egr cooler has failed once again inly this time leading to a more terrifying experience. My car was towed to the dealership but I am worried for myself and others with similar vehicles I would not like anyone to experience what I did. …
I was driving on the interstate when I heard a click from the back of the car. The gas gauge started to move downward as if I was losing gasoline. It eventually stopped and started moving back up, past where it was when it started decreasing. A little bit later the check engine light came on and the car started driving very sluggishly. I took the car into the Hyundai dealer and they found that the backseat was clicked out of place and a sensor was unplugged. This issue has since occurred multiple times. The back seat will pop out of place, the gas gauge will move beyond the gas that is in the tank, and finally the check engine light will come on and reduce the performance of the vehicle. The gas tank appears to be swelling and pushing up against the back seat which is causing it to pop. …
Whille driving back to Washington state my car check engine light came on and the car shut off while I was driving. I had to have it towed to the nearest city whi ch was Laramie Wyoming. There is no Hyundai dealer had to drive the car once it started back up to Cheyenne Wyoming it was checked. My on star told me there was a problem DTC P0145100 the status had red triangle the DTC power system powertrain and the DTC sub system EMS. I was told and given paperwork by the dealer and was told the car would need major repairs and could take up to 21 days once the work started it would have to he completed there because Hyundai had campaign dealing with my cars problem. I was told I could drive the car home but if the check engine light is flashing pull over immediately. …
NHTSA investigations
Loss of Motive Power
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021.
Engine complaints in other Sonata years
Frequently asked questions
How common are engine problems on the 2020 Hyundai Sonata?
NHTSA has 32 complaints about the engine & cooling of the 2020 Hyundai Sonata, 18% of the model year's 181 complaints.
Is there a recall for 2020 Hyundai Sonata engine problems?
No. NHTSA lists no engine & cooling recall for the 2020 Hyundai Sonata, though it has 4 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 2020 Hyundai Sonata engine problems start?
Half of the complaints with a recorded mileage happened before about 47,000 miles, and 50% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 1 fire and 1 injury to engine & cooling 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.