2021 Hyundai Santa Fe engine problems

“The contact owned a 2021 Hyundai Santa Fe. The contact stated that while his wife was driving 50 MPH, the vehicle unexpectedly caught on fire. The contact's wife became aware that the radio was inoperable before the failure. Additionally, the contact’s wife’s eyes were irritated, and there was a hot, harsh odor which grew stronger very quickly. The odor was inside the vehicle. The contact stated that the smoke was black, and flames started shooting out from under the hood to consume the vehicle. The vehicle was a total loss. The fire was extinguished by the Murphysboro Fire Department. The Fire Department was unable to determine where the fire had started. There was a Police report filed. The vehicle was towed to an impound lot. The failure mileage was approximately 58,000.”

“My check engine light came on, and my car was also feeling "sluggish" and slow to accelerate. I scheduled a service appointment at my local dealer 4 days later. At the appointment, the technician stated everything checked out okay and the check engine light was likely an "anomaly" or "outlier" but otherwise nothing to be concerned about since everything checked out "okay" and no problems were identified during their test drive. However, that very afternoon, I was driving down the interstate, where the posted speed limit is 70mph, when my check engine light came on again and suddenly lost power, drastically reducing my speed and could not accelerate faster than 39mph. Luckily, the interstate was not busy at the time (about 10:30-11:00 a.m. Saturday morning) and there were only less than 4 cars behind me that were able to easily switch lanes and pass me. I moved over to the shoulder to a complete stop and restarted my car. My check engine light remained illuminated and was still slow to accelerate and "sluggish" but was able to (slowly) reach interstate speed (60-70mph) until I reached an acceptable exit and safely made it to my destination. I have since used…”

“My 2021 Hyundai Santa Fe (VIN [XXX] ) is experiencing severe engine instability, including rough idling, hesitation upon acceleration, and intermittent stalling. These symptoms align with TSB 26-FL-001H regarding defective GDI fuel injectors. The vehicle has stalled in traffic, creating an immediate risk of a rear-end collision. Despite being within the 100,000-mile Powertrain Warranty, the manufacturer is refusing to perform the required diagnostic tests (GDS Fuel Pressure Drop Test) to identify the leaking injectors. This failure to diagnose a known fuel system defect poses a significant safety risk to the driver and other motorists. The primary safety risk is unexpected engine stalling while the vehicle is in motion or stopped at intersections. Additionally, the loss of power during acceleration prevents the vehicle from safely merging into high-speed traffic, significantly increasing the likelihood of a collision.”

“First instance at 50-55 mph the transmission violently shook the car when downshifting to accelerate on multiple occasions. Dealership diagnosed the problem as a faulty transmission and replaced it at 44064 miles on March 18, 2025. Second time the car failed to accelerate when merging into traffic while the engine revved very high. Again it was taken to the dealership and the diagnosis was faulty transmission. A second transmission was in stalled at 51331 miles. Second transmission began downshifting hard upon accelerating at highway speeds. Retuned to dealership and diagnoses was faulty fuel injectors and all four were replaced on April 7 at 52960 miles. On April 10, 2026 the car displayed a check engine light after the car began shuttering at highway speeds and was immediately returned to dealership where it’s pending a diagnoses. Failure to safely accelerate when merging make this vehicle a safety risk.”

“My vehicle loses power on the highway intermittently. I had my car set on cruise control at 55 and with no other vehicle in front of me the speed decreased to 45. It frequently sputters going up hills. My car has had 4 oil leaks.”

“Car misfiring symptoms like rough or shaky idle, hesitation and loss of power during acceleration, stumbling, unusual popping/backfiring noises, poor fuel economy, and a lit Check Engine Light. Felt vibrations / heard sputtering sounds, as if the engine skipped a beat, often becoming more noticeable under load or when accelerating. Sometimes, the issue goes away after restarting the engine.”