2020 Hyundai Sonata engine problems

“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 this point and my foot was removed from the brake pedal, the mechanical surge caused the vehicle to unexpectedly lurch forward, fighting against and nearly overriding the factory Auto Hold braking safety feature before finally holding. Luckily, no pedestrian was walking in front of my car when this occurred. No check engine light (CEL) or dashboard warning ever illuminated. This safety compromise is directly tied to an ineffective or adjacent remedy involving Service Campaign 9B1 (Opcode 40D219R0) and Safety Recall 286. Under this Opcode, a factory software flash deleted the standard OBD-II trouble code P0451and substituted it with a manufacturer-specific shadow code P14EE00.…”

“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 discovered as the issue and I am paying out of pocket to fix something that should not have failed and has leaked out refrigerent.”

“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 car jerks and shakes and the RPMs go up and down without me pressure on the gas pedal.”

“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.”

“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 lead to sudden engine damage, loss of power, stalling, or engine failure if the oil level drops between checks. The vehicle is only a 2020 model year, and this level of oil consumption appears abnormal. I am also concerned about possible emissions/catalytic converter damage from oil burning.”

“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 the general public to see if this is something that needs to be made aware for the safety of drivers to determine if their vehicle is at an accurate temperature.”