general problems of the 2011 Hyundai Sonata - part 1

This car has been having white smoke since I got it the smoke coming from the exhaust smells like oil burning.

Not sure . The car has been regulaurly maintenced and one day the emgine complagely seized up going down the road .

While driving at highway speed, the engine suddenly lost power and the brakes locked. I narrowly avoided a collision. This sudden failure left me unable to safely control the vehicle, placing myself and other motorists in immediate danger. This is not only a mechanical defect but a serious safety hazard that matches the exact conditions described in Hyundai’s prior theta ii engine recalls.

While driving on the highway, the motor all of a sudden lost all power and the brakes locked causing a collision. I've never had any problems until then. My car was in tip top shape with no issues until the engine / motor decided to defect. Hyundai she recall this engine issue before someone gets killed.

I recently got a radiator replaced and now my car won't reverse.

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently lost motive power. The contact was able to pull over to the shoulder of the roadway, where the vehicle failed to restart. The vehicle was towed to an independent mechanic, who diagnosed a failure with the engine. The contact was informed that the engine needed to be replaced. After investigating the failure, the contact related the failure to NHTSA campaign number: 21v727000 (engine); however, the VIN was not included. The manufacturer was not notified of the failure. The failure mileage was unknown.

I purchased this 2011 Hyundai Sonata (VIN: [xxx]) on [xxx]. A few weeks later, the engine started knocking, wouldn’t shift beyond 2nd gear, and wouldn’t go over 60 mph. A diagnostic test at express oil returned the error code p1326, which is tied to Hyundai’s recall campaign 132 for engine failure due to bearing wear. I brought the car to serra Hyundai in trussville, al. I provided my bill of sale, diagnostic code, and a recent oil change receipt, but Hyundai denied my engine replacement, saying there was a gap in service history between 2021 and 2025 — even though I was not the owner during that time. They confirmed it was a recall-eligible engine and admitted the failure matches the recall symptoms, yet are refusing to fix it — while also suggesting I “trade the car in” instead. This is a known safety defect, and I believe Hyundai is wrongfully denying legitimate recall repairs based on ownership history rather than actual engine failure. I am now without a working vehicle. I respectfully request that NHTSA investigate Hyundai’s denial of engine replacements under campaign 132 for new owners and hold them accountable. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

While driving our 2011 Hyundai Sonata on [xxx], my fiancée and I experienced sudden engine failure on [xxx]. The car suddenly lost power and began vibrating violently, then stalled completely and would not restart. We had to pull over in a dangerous area with no power and limited shoulder space, creating a serious safety hazard. A relative had previously scanned the vehicle and retrieved a p1326 knock sensor code, indicating a potential engine bearing issue. He cleared the code temporarily in an attempt to drive the vehicle again. However, when it failed on the freeway, we were forced to tow the vehicle twice—first to our home and then to anaheim Hyundai for diagnosis. Hyundai later denied warranty assistance, claiming "exceptional maintenance neglect" despite the fact that we provided all available oil change records since our 2017 purchase. We were not the original owners, yet were expected to produce records dating back to 2013. No sludge or varnish evidence was cited in the repair order, and the dealer simply claimed a seized engine. We’ve since been denied under both the extended warranty and goodwill policies, even though our engine displayed the same symptoms covered in the theta ii engine class action settlement. This failure was dangerous, left us without transportation, and has caused serious financial and emotional strain. We are reporting this because it reflects a potential ongoing safety risk for other Hyundai owners. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

2011 Hyundai Sonata had a theta ii engine replaced in September 2024 after engine failure. Hyundai paid for the engine through the extended warranty on the theta engines. Check engine light is still illuminated after new engine and after multiple visits to the dealership, they say the wiring harness is bad. Contacted Hyundai corporate who said they will not pay for anymore warranty repairs, even though the wiring harness was damaged from the bad engine or during the replacement. From my understanding, it is dangerous to drive a car with a bad wiring harness due to fire risk, loss of power, or loss of safety components.

The vehicle just died out of nowhere. Would not start back up. Has a clicking noise when trying start and then had a burning smell.

The contact owns a 2011 Hyundai Sonata. The contact stated after the vehicle was serviced, while driving 50 mph and depressing the accelerator pedal, the vehicle lost power. The contact pulled over to the side of the road while awaiting towing assistance. The contact stated that while waiting on the tow assistance, the contact became aware there was smoke coming from the engine. The vehicle was towed to the residence. The contact stated that several warning lights were illuminated. Neither a dealer nor an independent mechanic was contacted. The vehicle was not taken to be diagnosed or repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 112,000.

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle jerked, and the vehicle failed to accelerate as intended while depressing the accelerator pedal. The check engine warning light was illuminated. The contact stated that on a separate occasion, while driving 35 mph, there was smoke coming from underneath the hood. The contact pulled over to the side of the road and turned off the vehicle. The contact opened the hood, and there was smoke coming from the valve cover and coolant reservoir. The contact waited for the engine to cool down and the vehicle was able to restart. The contact stated that on a separate occasion, after turning off the vehicle after arriving at work, there was an abnormal bubbling sound coming from underneath the hood. The contact opened the hood and there were bubbles coming from the radiator. Prior to the failure, the contact had replaced the radiator, due to the engine overheating. Two weeks later the radiator hose detached. The contact stated that the fluid leaking from the radiator was dark brown and seemed to be mixed with slush. The vehicle was taken to an independent mechanic who determined that there was foreign parts inside the radiator. The contact was informed that the radiator needed to be replaced. The vehicle was not repaired. A mobile mechanic arrived at the residence and confirmed that the radiator needed to be replaced and an unknown valve on top of the engine needed to be replaced. The vehicle was not repaired. The failure became progressively worse, and the vehicle was no longer driven. The manufacturer was not notified of the failure. The failure mileage was unknown.

My girlfriend was driving my car at 70mph on [xxx] when suddenly the engine stalled abruptly with no warning. She had to coast over to the shoulder and come to a stop. At this point the engine would not turn over. If it did it was very challenged to turn over as if the engine was seized-partially or fully. My car was towed to my mechanic who later confirmed that the battery and starter were indeed good and that the engine seemed partially seized and even possessed metal shavings. On top of this my car has been consuming half a quart of oil every 400 miles as I check the oil everytime I get gas. So with this information my car seems to be fit for the Hyundai class action settlement recall #132 for the 2011 Sonata gdi engine. So I towed my car to coastal Hyundai of melbourne, FL, a dealership where all my records and maintenance have been done and are up to date. My car has been at this dealership for two weeks and they won’t even confirm that they have looked at it. I am under the understanding that it is costing Hyundai a lot of money to replace this engines and that they purposely stall hoping to somehow save money. I commute 72 miles round trip to work and have been greatly inconvenienced as I am having to borrow cars from family and figure out how to get to work. Any help in this regard is greatly appreciated. Thank you in advance! information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

I purchased a vehicle from cash car network on 4/3/2025. At the time of purchase, the vehicle's odometer showed a mileage significantly lower than what official records indicated. After purchasing, I reviewed the carfax report and the vehicle registration history, which documented that the actual mileage was approximately 270,000 miles — much higher than what the odometer displayed. This discrepancy suggests that either the odometer was tampered with or the instrument cluster was switched from another vehicle without disclosure, which violates federal laws related to odometer fraud (49 u. S. C. § 32701 et seq. ). Additionally, the vehicle experienced multiple serious mechanical failures shortly after the purchase, affecting its safety and drivability. I have since returned the vehicle to the dealership. I am filing this complaint to report potential odometer fraud, failure to disclose critical vehicle information, and the sale of an unsafe vehicle to a consumer. I am requesting that NHTSA investigate this dealership for possible violations of federal odometer disclosure laws. Supporting documentation, including the carfax report and registration history, is available upon request.

Engine just stopped with no warnings or signs. Will not run. Mechanic said motor was locked up.

On [xxx] my 2011 Hyundai Sonata seized and all lights illuminated on the dash while accelerating on to a busy street. I was able to pull to the side of the road but unable to restart the vehicle. I had it towed to wesley chapel Hyundai (27000 wesley chapel blvd. , wesley chapel, FL 33544) who notified me that there was an oil pan leak which was the possible cause of the engine failing. They corrected that issue and completed an oil change on 3/14/2025. I picked up the vehicle and there were no issues on the drive home which was approximately 11 miles. Then on [xxx] after driving approximately 24 miles to my place of employment, the engine started knocking but I was able to arrive and park with no issues. I immediately turned the vehicle off and contacted the closest dealership to have it towed there which was courtesy Hyundai (3810 w hillsborough Ave, tampa, FL 33614). I informed them that the vehicle was on it's way there and to notify me when it arrived. It wasn't until I called several hours later that they advised me the vehicle was received and that they would be submitting a claim to Hyundai motors of America for the engine. I had to continuously call to get updates as no one would contact me. I then was told that hma was requesting service records. I emailed those records to the service advisor on 3/20/2025. I had not heard anything for about a week so I contacted the service manager who stated hma is requesting additional service records. I asked why I was not informed sooner but was unable to get a real answer. I then forwarded those documents directly to the manager on 3/28/25. I was then notified on 4/1/25 that hma had denied the claim due to negligence of the motor despite providing the requested documents as well as confirming via Hyundai's website that my vehicle was affected by the Sonata engine connecting rod bearing inspection recall campaign. I am now being quoted $4059. 89 + tax to replace the engine. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Unknown, makes a disturbing sound upon starting the vehicle like something inside the engine rattling, access oil consumption and burning smell , replaced valve cover gasket, still smelling oil burning.

Desconocido.

I had bought this car off facebook marketplace after confirming with my dad that it was a good car, when I had finally saved enough. After I took it home the check engine light had come on not too long after, the engine stalls when turning the key, pressing on the brake helps start the engine. Turns out the car was a salvage title and my dad didn’t know that and I didn’t know what that was.

When my car is turned on there is a very noticeable shake coming from the engine area. It's not that bad once the car is driving. However, I was driving 40 miles an hour when my check engine light came on, then I was unable to accelerate and my car stalled (it's an automatic car). Once my car started up again, the check engine light was flashing, and I could only drive at like 15-20 miles per hour for my speed. Made it to o'reilly and had them run the check engine light codes for me and it popped up with the p1326 code regarding the knock signal range/performance. I recently got a check engine light code for a p0449 evap vent control valve (it wouldnt allow me to pump gas into the car). I'm unsure if the issues are related but wanted to provide all the details.

After my car gets going and warms up, the engine has a problem. When it is time for the engine to shift to a higher gear, it makes a revving sound like the clutch has been pushed in and the gas pedal is being pushed. This mostly happens around 25 and 45mph. When you hit the as to make it stop it jerks and sometimes skids. If you take you foot off the gas it stops, but also slows down. When you hit the gas again it jerks again. If you try to speed up to get it to stop, it jerks again and this time pretty badly.

After taking my mom to the airport the vehicle engine blew up what absolutely no warning at all leave me on the side of the road the key keep getting stuck inside the car.

The car engine seized while driving on the highway.

My car will randomly shut off while I’m driving. My seatbelt comes undone my door has opened while I was driving down the highway.

The contact owns a 2011 Hyundai Sonata. The contact stated while driving at an undisclosed speed, a loud knocking was present coming from the engine as the check engine warning light illuminated. The contact also stated the vehicle lost motive power. The vehicle was able to restart, however the failure recurred. The vehicle was towed to the dealer where it was not diagnosed or repaired. The manufacturer was made aware of the failure and confirmed that the VIN was not included in NHTSA campaign number: 15v568000 (engine) due to not having the paperwork and dealer deemed the vehicle with poor maintenance. The approximate failure mileage was 280,000.

Leaking.

Car is overheating. Took it to a mechanic they replaced the thermostat but car is still overheating, jerking and so much more. The mechanic wants to charge more to fix it. I got a second opinion from another mechanic and after he reviewed the paperwork from the first mechanic. He searched my VIN number and told me to contact this number because my vehicle is on a recall list. So I need someone to contact me about where and how we can get my vehicle fixed.

Car spontaneously caught fire while turned on. First smoke started coming from under the hood. Within three - five minutes, the car erupted in flames followed by a minor explosion that burned more than half of the car causing a total loss.

Oil keeps drying out and keep smelling antifreeze.

Engine consumes oil profusely. 175000miles. Complaint #: [xxx], 8/23/24. Car is not drivable parked. Common complaint. Should have been recalled. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The contact owns a 2011 Hyundai Sonata. The contact stated while driving 20 mph, several unknown warning lights illuminated. The contact stated while attempting to make a right turn, the steering wheel seized, and the electrical system became inoperable. The vehicle was not diagnosed or repaired. The VIN was not included in NHTSA campaign number: 20v746000 (engine) nor 18v137000 (seat belts, air bags). The manufacturer was notified of the failure. The failure mileage was 100,000.

On July 19 I started my car and there was a loud knocking noise coming from underneath my hood when I lifted the hood the knocking sound was coming from my engine I’ve had this car for 3 years never had any problems or issues at all with my car not sure what’s going on or if there are any recalls on parts for my car.

The car has throw a rod in the engine. The safety of my dog and I was okay. And the safety of other drivers were good also. Yes it was inspected and there were no lights on when the car went down.

The contact owns a 2011 Hyundai Sonata  . The contact stated that while driving at an undisclosed speed, the vehicle made an abnormal sound and as the contact was attempting to turn the vehicle hesitated. The vehicle was able to be restarted but soon again made the abnormal sound and stalled. The contact stated they smelled smoke upon veering the vehicle to the shoulder. When the contact exited the vehicle they discovered a liquid substance coming from the under carriage. The vehicle was towed to an independent mechanic and was told the engine was cracked and advised the contact to take the vehicle to the dealer. The dealer was not contacted. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure mileage was approximately 174,000 .

The contact owns a 2011 Hyundai Sonata. The contact stated that while her daughter was driving at approximately 80 mph, the brake pedal was depressed but was stiff and difficult to depress. The contact stated that her daughter accelerated to steer the vehicle away from slower traffic. The contact stated that her daughter depressed the accelerator pedal however, the vehicle failed to respond and started losing motive power. The contact stated that her daughter was able to steer the vehicle to the side of the road and stop the vehicle. The contact stated that the check engine and check brake and several other unknown warning lights were illuminated. The contact had the vehicle towed to an independent mechanic. The vehicle was not diagnosed or repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 120,000.