2020 Hyundai Tucson: sudden loss of power

Filed Jul 28, 2026 · Engine · UT

The engine lost power while driving, and the vehicle entered a reduced-power mode. The check engine light began flashing, and the engine made a loud knocking noise during acceleration. A diagnostic scan showed code P1326 (Knock Sensor Signal Range/Performance). The knock sensor was replaced, and the engine oil was refilled after discovering an oil leak. The vehicle operated normally for a short time, but the same symptoms returned. The vehicle is available for inspection. The vehicle suddenly lost power while traveling approximately 70 mph on the highway, making it difficult to maintain speed and safely keep up with traffic. This created a risk of being struck by other vehicles or causing an accident. The problem has since recurred during normal driving. The problem has been reproduced multiple times. A diagnostic scanner consistently identified code P1326. The knock sensor was replaced and the engine oil was replenished, but the same symptoms returned after several trips. The vehicle has not yet been inspected by a Hyundai dealership. The vehicle has been inspected by the owner and a family mechanic who replaced the knock sensor and identified an engine oil leak. It has not yet been inspected by Hyundai, law enforcement, or an insurance representative. There were no warning lights or messages indicating low engine oil or an oil leak before the failure occurred. I had the engine oil changed approximately one month before the incident. While driving on the highway at approximately 70 mph, the vehicle suddenly lost power, the check engine light began flashing, and the engine started making a loud knocking noise. After inspecting the vehicle, we discovered it had an engine oil leak and the oil level was low. Before the loss of power, there were no warning signs that the engine was losing oil or that there was an oil leak.

Filed Jun 1, 2026 · Engine, Transmission · PA

While driving, the engine began making a loud knocking/rattling noise and the check engine light began flashing. The vehicle experienced a loss of power and was unsafe to continue operating normally. The vehicle was taken to a Hyundai dealership for diagnosis. The engine requires replacement. Hyundai denied coverage, claiming excessive oil consumption and/or maintenance concerns. However, upon inspection, the dealership removed the valve cover and advised that the engine was internally clean and showed no significant sludge buildup consistent with severe neglect. I am concerned that this engine failure may be related to known Hyundai engine issues involving the 2.4L GDI engine. The failure occurred well before the expected service life of the engine and created a potential safety hazard due to the loss of power while driving. I am requesting that the federal safety agency review this failure and determine whether similar failures are occurring in 2020 Hyundai Tucson vehicles equipped with the 2.4L GDI engine.

Filed Feb 10, 2026 · Brakes, Engine · NJ

Component: Engine / Electrical System / Fuel System Incident Date: February 9th, 2026 Vehicle Speed: 45-50 MPH Description: While traveling at highway speeds on a major roadway, the vehicle experienced a catastrophic and sudden engine stall without any prior warning or dashboard indicators. The engine shut off completely while in motion, resulting in an immediate and total loss of power steering and power-assisted braking. I was forced to perform a high-effort emergency maneuver in heavy traffic to reach the shoulder and avoid a collision. This vehicle is used to transport myself, my coworker and my family whose lives was placed in immediate danger by this failure. Since the start of the financing agreement, this vehicle has a documented history of recurring sensor issues and failed repair attempts at the dealership (Route 1 Hyundai). The dealership has previously attempted to address electrical/sensor malfunctions, but the root cause remains unresolved, leading to this life-threatening stall. I believe this is a significant safety defect in the vehicle’s electrical or fuel management system that poses an unreasonable risk of accidents and injury.

Filed Jan 14, 2026 · Electrical, Engine · OH

On December 27, 2025, while driving, the engine suddenly lost power and the vehicle entered limp mode and became undriveable. A warning light appeared and diagnostic code P1326 was later confirmed, indicating engine bearing failure. The vehicle could not be driven safely and required towing to a Hyundai dealership the following day. The engine failure caused a loss of propulsion safety risk. The vehicle remains out of service pending a full engine replacement. The vehicle is available for inspection at a Hyundai dealership.

Filed Nov 18, 2025 · Engine · PA

the engine failed without warning. While going up a hill the car lost power. Yes, the dealership said it was a known problem. Yes, the dealership fixed the problem by putting in a new engine which I was responsible for 5% of the cost which was 739.66. The only warning that was given was after the car failed, the engine light and the oil light went on.

Filed Aug 23, 2024 · Engine · CA

I was driving 45mph on a major road when, the vehicle with out warning lost power, I heard rattling, lost power. I turned it back on by the power button, drove into gas station where the check engine light flashed, oil light flickered and didn't turn back on. Car was rattling, turned it off. Got out, checked engine under hood and components. Dip stick had oil. Car had no signs of anything else. Vehicle would not start, called tow. Waited 5 hours for tow. Did not hear back from Hyundai dealership in a month. Submitted all articles of maintenance. Going on two months and was told to resubmit. Three months prior, engine over heated due to original hose component coupler piece melting.

Filed Feb 27, 2022 · Driver assistance · OH

It happened on two different occasions but only when driving at high speed using the Cruise Control. Here is what happened. Driving on the Cruise Control I “Set” it to 70 mph. Driving on the two lane highway with both lanes blocked by other vehicles, I pressed the “brake” pedal. The car slowed down and I continued driving at a lower speed. When traffic in front of me cleared, I pressed the “Resume” button on Cruise Control. With no obstacles in front of me, my car was supposed to accelerate to the previously set speed of 70 mph. Instead, it was slowing down. When pressing the gas pedal the car was not accelerating. It felt like the car “lost power.” It felt like the automatic transmission shifted to a Neutral or may be the lowest gear. Pushing the gas pedal did not do anything and on both occasions I managed to steer the car to a road shoulder. It was a scary situation with heavy fast moving traffic on a narrow mountain highway. I stopped the car, then tried to go again. It would go very slow on, what felt like, the lowest gear without acceleration. I then stopped the car again and turned off the engine. Turning the ignition off resets the electronics and I was able to get back on the road. The car continued to drive normally on Cruise Control until the same happened again the next day. As I said, it happened on two different occasions. From there on I avoided pushing the “Resume” button on Cruise Control and I am afraid of using it from now on to avoid potential accidents. I consider this to be a life threatening malfunction and I reported it to Hyundai’s Customer Care. They opened the Case Number and suggested going to the nearest dealer. I took the car to the nearest dealer. They kept it for several days, drove 40 miles and, as I expected, were not able to replicate the problem. In my opinion, this problem needs to be analyzed by the engineers not a dealership's technician. Is speed a factor? Is temperature a factor? What is the factor?

Filed Sep 1, 2021 · 38,000 miles · KY · crash · 1 injury

The contact owns a 2020 Hyundai Tucson. The contact stated that while driving approximately 65 mph, the instrument dashboard display suddenly blacked out and the steering wheel malfunctioned causing the driver to lose control of the vehicle and crash down an embankment into a tree. The contact mentioned that when she attempts to exit because the vehicle was on the edge of an embankment when she exits the vehicle she fell into a tree then climbed up to the roadway where she was found unconscious. During the incident, the driver sustained a fractured left shoulder and head trauma. The contact currently was being seen by a Neurologist for her head trauma. A police report was taken at the scene and the vehicle was towed away. It took over an hour for the vehicle to be retrieved from the embankment. The cause of the failure was not determined. Prior to the crash, the vehicle had been serviced on multiple occasions for exhibiting a loss of power and hesitation to accelerate. The vehicle was taken to the local dealer who replaced the transmission and reprogrammed the computer software but the failures continued to occur. The manufacturer was notified of the failures. The failure mileage was 38,000.