Table 1 shows one common engine and engine cooling related problems of the 2021 Hyundai Tucson.
| Problem Category | Number of Problems |
|---|---|
| Engine And Engine Cooling problems |
My 2021 Hyundai Tucson has experienced repeated engine-related failures associated with a knock sensor (p1326) fault that causes the vehicle to enter limp mode and lose power while driving. This issue has occurred multiple times at approximately 15,000, 17,000, 41,000, and 90,000 miles and has resulted in four separate incidents requiring towing. During these events, the vehicle suddenly loses power and cannot maintain normal driving speed, creating a hazardous condition while in traffic. The vehicle has undergone multiple repair attempts, including an ecm update and three knock sensor replacements. Despite these repairs, the issue continues to recur and no root cause has been identified. Hyundai has not provided a permanent fix and has advised continued operation of the vehicle unless the issue occurs again. This ongoing condition presents a safety concern due to the risk of sudden loss of power while driving.
While driving on the freeway, my 2021 Hyundai Tucson se (72,021 miles) suddenly and without warning lost power and entered limp mode. I was able to safely maneuver to the shoulder and exit the freeway. The check engine light came on and is currently flashing. I took the vehicle to autozone where code p1326 was retrieved. I then took it to pep boys for a full diagnostic where p1326 was the only code present. The pep boys report states the vehicle requires immediate attention. The vehicle remains in limp mode and the check engine light is flashing. The vehicle is not being driven as it cannot safely reach freeway speeds. I contacted Hyundai customer care and was assigned case # xxx. I also contacted a Hyundai dealership who attempted to charge a $225 diagnostic fee despite p1326 being a known Hyundai defect covered under recall/service campaign. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
The contact owned a 2021 Hyundai Tucson. The contact stated that while driving at 10 mph, an abnormal clicking sound was coming from under the hood. No warning lights illuminated. In addition, the contact managed to pull over to the shoulder of the road, where white smoke was noticed leaking from under the hood, and the intensity was increasing while the smoke turned black. The local fire department arrived on scene to extinguish the fire. The source of the fire was not identified. It was unknown if a fire report was filed. A police report was filed. No injuries were sustained, and medical attention was not sought. The vehicle was towed to the contact's residence. The vehicle was deemed a total loss as it was majoily consumed by the fire. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 65,000.
I have been adding oil to this engine excessively for more than 3 years. . I have had appointments with the dealer where they flat out told me bring it back when the engine fails. I finally got n appointment and was told the engine needed to be replaced. That was 2 weeks ago. . They are now denying the claim. . . Have had my car for 2 weeks. . No loaner. . And decided to deny what they told me.
I am the original owner of this car and in June 2025 I brought my car to Hyundai from noises and they told me it had no oil despite me being up to date with oil changes on the vehicle. They told me they were going to do an oil consumption test and once they did that the engine was denied. 6 months later 3 days after an oil change and no check engine light on, the engine fails while I’m on the side of the highway. This car is not safe. Check engine light was not on and I am always up to date with my cars maintenance.
Oil light comes on between changes at about 1500 miles before needing one, oil does not show on dipstick and have to repeatedly put on in engine. Chance of engine seizing or jumping time.
The contact owned a 2021 Hyundai Tucson. The contact stated that immediately after purchasing the certified vehicle, the vehicle went into limp mode while her grandson was driving approximately 65 mph, and the vehicle decelerated to 7 mph. The vehicle was towed to the local dealer who diagnosed that the nox sensor had failed and needed to be replaced. The vehicle was repaired but while leaving the dealer, the failure reoccurred. The vehicle was towed back to the dealer who replaced a second nox sensor and the catalytic converter. The contact stated that days after retrieving the vehicle, the failure reoccurred, and the vehicle was towed back to the dealer who diagnosed that the nox sensor had failed for a third time, within several days of owning the vehicle. The vehicle was traded in. The manufacturer was notified of the failure. The failure mileage was 28,944.
Engine started making a knocking sound, then the oil light came on followed by the check engine light. Accelerates and decelerates on its own. Was forced to immediately pull over across three lanes on interstate 95. It’s been over two weeks and I’ve yet to hear if Hyundai is going to cover a replacement engine. However, what happened is exactly what they have listed on their website ?? what to look out for check-engine check engine oil-light engine oil pressure a knocking noise from the engine that increases in frequency as the engine rpm increases. Reduced power and/or hesitation and vibration. Illumination of the “check engine” light in the instrument cluster. Illumination of the “engine oil pressure” warning lamp.
My family’s safety is at serious risk with my 2021 Hyundai Tucson, which I’ve owned only 55 days. This vehicle has stalled three times while driving, putting me and my two young children in immediate danger. Each time, the car operated normally until a flashing engine light appeared, rpms spiked, and the vehicle suddenly lost all power—entering “limp mode” and unable to exceed 3,000 rpm or 50 mph. The first failure occurred 9/14/25 while merging onto the interstate, forcing me to lose power mid-acceleration as surrounding vehicles slammed their brakes to avoid collision. 13 days later, it happened again in stop-and-go traffic, leaving me stranded on the shoulder. Both incidents occurred without warning or prior check-engine lights. The third—and most terrifying—incident was on October 17, 2025, when the engine completely died 300 miles from home on a busy highway. My children, ages 4 and 6, were terrified as cars sped by. We were extremely fortunate not to have been hit. I am urgently requesting assistance for the immediate replacement of this vehicle’s engine. It is covered by Hyundai’s 15-year/150,000-mile extended warranty, clear evidence the company was aware of these issues. Service records from the previous owner-that I was told about by Hyundai show ongoing engine problems and recalls since 2022 further proof this vehicle should have been retired from service as a parent, I’m very alarmed that Hyundai refuses to act until “catastrophic damage” occurs. This policy is irresponsible and endangers entire families. There’s at least 50 NHTSA complaints describing identical issues; stalling, power loss, and bearing failure linked to defective connecting rod bearings. Yet, Hyundai has denied a replacement, insisting on waiting for further damage and failures in operation. I beg you to intervene and prioritize my family’s safety before tragedy inevitably strikes. My children should not be put at risk due to corporate negligence, greed and absence of accountability.
Engine started making a knocking sound, light came on. Accelerates and decelerates on it's own. Dealership will not provide a diagnosis in any way, but says complete engine replacement is the answer. Car has been at dealership for almost a month.
While driving on a major highway, my car went into limp mode topping out at 60 mph then decreasing before going back to 60. My check engine light was also blinking, not solid.
We were driving and the engine light started flashing and buckling. The vehicle had been properly maintained with oil changes. We have oil changes receipts from our mechanic. Hyundai refuses to cover it under their warranty even though there are documented issues with the make and models of 2021 Hyundai tuscons.
When going through auburn, al with speed limit of 70 mph my car engine started blinking on and off then my car dropped down only allowing me to go 60 mph.
The vehicle experienced a catalytic converter efficiency failure that was confirmed by an authorized dealership in January 2025. The dealer indicated the catalytic converter required replacement; however, the replacement was not performed, and the vehicle was returned to service with an unresolved emissions defect. Less than one year later, the vehicle developed recurring emissions system failure, loss of power, drivability issues, and repeated warning indicators. The vehicle is currently out of service while additional components, including oxygen sensors and spark plugs, are reported to be affected. The manufacturer is declining to replace the catalytic converter and is attributing the condition to oil consumption despite the prior unresolved emissions failure. The issue has been confirmed by dealership diagnostics and has resulted in prolonged loss of use of the vehicle. This appears to be a continuing engine and exhaust/emissions system defect that was not properly remedied when first identified and may affect safe operation of the vehicle.
The contact owns a 2021 Hyundai Tucson. The contact stated that while driving at various speeds, the check engine warning light was frequently illuminated on the instrument panel. The contact had taken the vehicle to various independent mechanics and was informed that the engine was consuming an excessive amount of engine oil. The contact had taken the vehicle to a dealer for service, and upon inspection, the contact was informed that the engine needed to be replaced. The contact was provided with an estimate for the engine replacement. The manufacturer was notified of the failure but offered no assistance. The contact was initially informed that the vehicle was covered under warranty; however, the contact was later informed that there was no warranty on the vehicle. The vehicle was not yet repaired. The failure mileage was approximately 89,000.
Around November 1, 2024 my 2021 Tucson check engine light came on. I had this checked out and was told by a mechanic that it was the camshaft sensor. I had this repaired and then on November 23rd while traveling to ohio my check engine light started flashing and needed immediate attention. I was on the west virginia turnpike when this happened and it caused the car to go no more that 45 mph in a zone marked 65mph. We got this immediately checked out and repaired and then 4 days later the same thing happened while in ohio. It was taken to deihl Hyundai in massillon, ohio and they once again made this repair with video evidence of said repairs. Once again while driving at freeway speed on December 23rd my car experienced this malfunction. The same dealership fixed it once again with direction from Hyundai. I am concerned for this is an ongoing problem and could cause serious injury to myself or others in my vehicle if this would happen once again on a freeway.
There was a recall on this engine which I had updated the knock sensor campaign. While on the highway the engine light started flashing and the speed was reduced to 20 mph on a major highway. I had to almost cause a wreck to get off highway. The vehicle went into limp mode with no prior indication.
The contact owns a 2021 Hyundai Tucson. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed, but the vehicle failed to accelerate as intended. The check engine warning light was illuminated. The contact stated that the vehicle failed to exceed 20 mph. The contact stated that the failure had occurred while driving on a busy highway. The contact safely pulled over to the shoulder of the roadway. The vehicle was then towed to the dealer, where it was diagnosed with engine knock sensor failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The manufacturer informed the contact that the repair was not covered under an unknown recall due to a lack of maintenance records. The contact was advised to contact the better business bureau. The failure mileage was approximately 60,000.
My check engine light came on in the vehicle and immediately the acceleration declined and I wasn’t able to go above 50 mph. I brought the vehicle to the dealership to which the code 1326 came up. I was told it is a rod bearing engine failure and I need a new engine for the vehicle. I was also told my vehicle doesn’t qualify for the recall already made for this damage and code number.
Oil consumption problems.
Crank sensor went bad and engine needs rebuilt.
What component or system failed or malfunctioned, and is it available for inspection upon request? steering column. How was your safety or the safety of others put at risk? steering column would not disengage and remained locked up after the vehicle was started and in gear. This have caused me to almost get into a few collisions for the same issue. I have had friends and family, most recently my daughter, in the vehicle when these issues have occurred. I have almost collided with walls, cars, etc due to this issue. Has the problem been reproduced or confirmed by a dealer or independent service center? no. Despite the numerous videos I have presented documenting these incidents, they state they have been unable to reproduce. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? manufacture has not inspected the vehicle and keeps sending me to the local dealership where the vehicle was purchased from. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? yes. During the issues where the steering column does not unlock or disengage, it displays a yellow light with a car and key symbol in it. During other issues I have experienced with this vehicle (phantom braking, acceleration / power issues, random dash controls turning on, and the electric e-brake failing to properly disengage, there have been no lots on the dash that were noticeable. Restarting the vehicle tends to rectify the issue.
I was contacted by Hyundai last year about a possible recall on my engine so I brought it in October 2023 to have it checked out. I was told that everything with the car was fine. Fast forward to last week 02-21-2024 and my engine starts shutting off while driving on the highway? I have it towed to a new dealership in jacksonville FL jenkins Hyundai I believe. They inform me that it is indeed the engine and it will be replaced for free under warranty. However, it’s been over a week and the parts for the car are still not available. I have researched online and found I am far from the only one this has happened to. I was not given a loaner car and they did not offer to pay for my rental but I was told they would reimburse me. I was also told that they would just pay every week for a rental car for me but then I was later told that that was a flat out lie. After March 7th when the rental car I have is to be returned I can no longer afford a rental car and will not have access to reliable transportation. This could potentially result in me losing my job. This is unacceptable and Hyundai should be investigated and held accountable for selling cars they know have faulty engines.
September 15, 2023 while driving on the expressway my engine light came on. Vehicle towed to world Hyundai dealership and it was diagnosed as engine seized.
I was merging onto interstate traffic when the vehicle suddenly stuttered and decelerated. I managed to merge, then cross over several lanes of traffic and pulled over. Thought maybe a fuel problem (I had just filled the tank), or overheating. It only has 24k miles on it, and I've faithfully taken the vehicle to the dealer for regular service intervals, so I know it is not a fluid leak or problem. After a few minutes, I was able to start the car again, but it immediately shut down. Did this several times before giving up and calling for a tow truck. Had it towed to the dealer, and the next day they told me it needed a new engine, but the service department needed approval from corporate Hyundai. I'm waiting with baited breath.
The contact called on behalf of his girlfriend who owned a 2021 Hyundai Tucson. The contact stated while driving 5 mph in the driveway, there was steam coming out from under the hood. There was no warning light illuminated. The contact parked the vehicle. The contact stated that as he opened the hood, flames came out. The contact's girlfriend also saw flames coming out of the a/c vents. The contact closed the hood and assisted his girlfriend and his pet in exiting the vehicle. The contact stated that his girlfriend slipped and fell while exiting the vehicle. The contact's girlfriend sustained back pain and the contact sustained flash burn. There was no further information provided. The contact stated that the entire vehicle caught on fire. The contact was able to extinguish the fire with the assistance of the fire department. A fire department report was filed. No police report was filed. The insurance company technician determined that the fire originated from the engine compartment. The vehicle was totaled by the insurance company and remained in the contact's driveway. The dealer was not notified of the failure. The manufacturer was notified of the failure, and a case was opened. The failure mileage was approximately 25,000.
Check engine light comes on flashing for a knock sensor. This has happened four times. Since it is flashing, car goes into limp mode and won’t go over 2000 rpm, low speeds and slow/no acceleration. It is dangerous due to happening on highways and going from cruising speeds to a crawl, with minimal ability to accelerate, very quickly. Sensor has been updated once and sensor has been replaced twice. Currently dealing with corporate after the fourth time of this issue happening. I am still fighting this issue and it’s looking like I will need an attorney.
I already replaced 3 catalytic converters and I am at 31000 miles. They finally decided to do an oil consumption test but it passed. The other day my car started shaking and my ignition coil and spark plugs were also bad which somehow is related to my engine issues.
March of 2021 I purchased a new Hyundai Tucson sel. I have performed all required maintenance (at the dealer no less). In may of 2022 the dealer performed the recall campaign 966. Since that time, my Tucson has had to go to the dealer 5 times for a p1326 code. This resulted in the check engine light flashing and the car going into protection or limp mode. The vehicle would not accelerate past 30 mph and would not exceed 2000 rpm. This has happened as I have accelerated from either a stop or while in traffic. As of yet the dealer has been unable to permanently resolve the problem. They have replaced the knock sensor. The dealer has replaced spark plugs. The dealer has also replaced the catalytic convertor. They also recently scoped the cylinders and cleaned the engine with pressurized engine detergent. In the days and weeks prior to the check engine light, I can always tell that failure is imminent. The gas mileage will slowly drop off during both highway and city driving. Additionally, I can feel through the gas pedal hesitations and slight rhythmic pulsing. Lastly, I can feel gradual power loss in acceleration and very slight hesitations in acceleration as well.
Recall code 966 22-01-028h-1 think and investigation is needed on these recalls. Apparently the engine can catch fire while the motorist is driving. I'm scheduled to drop my car off on the 9th and was told they may need to keep for 3-5 days. Thes vehicles should not be on the road at all and rental cars should be provided free of charge until the manufacturer works out all the problems.
Received recall notice that the possibility exist that a battery compartment fire could happen. Recall notice also stated that vehicle should �not be parked indoors. � the recall notice also stated �an electrical short in the abs module could increase the risk of an engine compartment fire. � so we don't dare park the car in our garage since it is located beneath our home, thereby leaving a new car out in the elements at all times. In addition as senior citizens our safety and well being are being jeopardized as we cannot enter our vehicle from inside our home, but must enter from the street in all types of inclement weather. We called the service department but did not receive a call back. We reached out to our salesman and he was the one who gave us information on the recall and added our name to the repair list. However when we didn't hear from them with an update we took a drive to the dealer. During the visit to the dealer in March we were told the piece is on back order. Today I called the service department and was told there is no date yet to fix this recall. How long are we expected to wait for the �fix� and to leave our car outside?.
The contact owns a 2021 Hyundai Tucson. The contact stated that while driving 35-45 mph, the vehicle shut off unintendedly. There was an abnormal rattling sound coming from the vehicle. Additionally, the contact stated that the vehicle failed to accelerate while driving. There were no warning lights illuminated. The vehicle was taken to the local dealer where it was diagnosed that a rod bearing, and the engine needed to be replaced. The vehicle was repaired; however, the failure recurred. The vehicle was taken to another local dealer, Hyundai of orange park (7600 blanding blvd, jacksonville, FL 32244); who determined that the coils needed to be replaced. The vehicle was not repaired. The vehicle was taken to an independent mechanic who replaced the coils and determined the failure was due to the engine. The vehicle was repaired but the failure reoccurred. The manufacturer was contacted, but no additional assistance was provided. The failure mileage was approximately 124,500.
Severe hesitation when attempting to accelerate from a stop. Car does not move, requires sveral attempts to press the accelerator before the car responds, extremely dangerous when entering an on ramp, merging onto a highway, or in heavy traffic. This has been an ongoing problem with this car, has not been rectified , Hyundai refuses to acknowledge the problem.