2020 Hyundai Sonata engine problems

What owners report

• “Vehicle experienced intermittent, severe powertrain defect resulting in a critical safety hazard. Between 30K and 36K miles, the vehicle underwent 3 violent highway deceleration episodes. During these events, the engine began shaking, escalating to violent shaking; with deceleration and coming to a stop, it would shake, then sputter as if it would die. Coming to a complete stop, a total stall was prevented only by the ECM forcing a limp mode lock at 1200 RPMs. When Auto Hold was engaged at t…”

  NHTSA complaint · filed 10/15/2026

• “The A/C evaporator core and the core seal needs replacing on 2020 Hyundai Sonata. Car is 6 years old. I already have a confirmed diagnosis with a PPM refrigerant leak tester at the condensate drain line The diagnosis is 100% confirmed. The evaporator is leaking heavily—we pulled 274 PPM at the drain tube and 177 PPM inside the cabin behind the glove box so refrigerent has been leaking out of the vents. My wife and I were getting headaches for no reason. Our AC has failed and this problem was dis…”

  NHTSA complaint · filed 09/03/2026

• “My vehicle while driving, it is jerking and shaking. When I come to a stop, the cars rpms go up and down while the car is shaking. When I pressed the gas pedal to accelerate the car will not accelerate as normal and the car jerks as I’m driving it. The RPMs rev up and down without any pressure placed on the gas pedal. The check engine light came on.The miles per hour only allows me to put one digit. I wanted to clarify that the problem is occurring anywhere between 0 mph to 65 mph when these the…”

  NHTSA complaint · filed 07/10/2026

• “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 co…”

  NHTSA complaint · filed 07/10/2026

• “My 2020 Hyundai Sonata 2.5L is experiencing excessive engine oil consumption. At approximately 88,063 miles, Great Lakes Hyundai documented that the engine oil level was 1.30 quarts below full after an oil-consumption check. The dealer topped off the oil, submitted photos and a prior-authorization/goodwill request to Hyundai, and Hyundai declined assistance. The dealer recommended combustion chamber cleaning with an estimate of $979.76. I am concerned that this excessive oil consumption could l…”

  NHTSA complaint · filed 06/14/2026

• “For my vehicle the Check Engine light has been on continuously throughout the last 6 months and mechanics are going to have to replace the thermostat. Multiple auto mechanics have indicated online that this is a very common problem with many Hyundai vehicles from 2020-2023 and can be a danger due to temperature control not being accurate for vehicles (Code P2181). Many owners of these Hyundai vehicles have experienced this issue leading online and this issue should be made aware to Hyundai and t…”

  NHTSA complaint · filed 06/09/2026

• “2020 Hyundai Sonata SEL Plus, VIN [XXX] . A/C system fails due to refrigerant leak that empties the system completely within 1-2 weeks of recharge. Leak cannot be located through standard external inspection. First noticed reduced cooling summer 2025. Driver's side loses cooling first, then passenger side fails days later — pattern consistent with evaporator core leak in dual-zone system. In September 2025, independent shop found system completely empty, recharged it, and attempted leak detectio…”

  NHTSA complaint · filed 05/31/2026

• “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 calle…”

  NHTSA complaint · filed 05/08/2026

Unverified owner reports from NHTSA's public complaint database.

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