2011 Hyundai Sonata Engine

I am reporting a safety-related engine failure involving my 2011 Hyundai Sonata 2.0T. In November 2025, at approximately 90,000 miles, the vehicle experienced a sudden engine failure while driving, including loss of power and abnormal engine noise. This created an unsafe driving condition and required the vehicle to be removed from service. Component/System Involved: The engine (Theta II 2.0T) suffered a catastrophic internal failure. The engine and internal components remain available for inspection upon request. Safety Risk: The sudden loss of engine power reduced my ability to maintain speed and maneuver in traffic, posing a safety risk to myself and other motorists. Confirmation and Inspection: The failure was confirmed by an authorized Hyundai dealership, which inspected the vehicle and documented the internal valve train condition through photographs. Hyundai Motor America reviewed the claim and issued a written denial. No independent third-party technical inspection was performed. Prior Symptoms: Before the failure, the vehicle had a history of excessive oil consumption requiring frequent monitoring and oil addition despite regular maintenance. Abnormal engine noise was present for approximately one minute before failure. No warning lights adequately predicted the sudden failure. Additional Context: This vehicle is equipped with a Theta II engine, which has been the subject of prior recalls and settlements related to internal engine defects. Hyundai denied warranty coverage alleging “exceptional maintenance neglect”; however, inspection photos show a well maintained valve train with no sludge or oil flow obstruction, only light surface varnish consistent with normal engine aging. I am concerned this failure represents a continuation of a known Theta II engine defect (confirmed by Hyundai technician who performed inspection with OBD code P1326 followed by engine failure) and poses a serious safety risk due to sudden loss of engine power while driving.

My Hyundai Sonata has encounter two failing cylinders (compression loss) due to scoring. When driving in the highway I got engine shudder and loss of power (speed) that could have put me in dangerous driving condition, accident or other. These GDI engines are notorious for poor oil circulation due to faulty designed piston rings. Hyundai has long history with these poorly manufactured engines and class action lawsuits. I notified Hyundai but they are not willing to remedy the situation. I have worked with local dealership Miller Hyundai, as well as corporate. All I get are excuses and that I’m not covered. These engines are completely problematic with oil consumption and oil blow by, causing seizing, rod bearing failure, carbon buildup, cylinder damage, etc. The info on the internet over customers and these GDI engines is overwhelming. Oil related Fires are another issue as well. Hyundai needs more accountability than the class action for rod baring failures. Because of the damage to my pistons, I could have gotten in accident with loss of power on highway…full due to poor piston rings, damage from improper oil flow and near complete engine failure.

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving approximately 30 MPH, the vehicle unexpectedly lost motive power. There was no warning light illuminated. The vehicle became inoperable and could not be restarted, and the vehicle was towed. The vehicle was towed to a dealer, where it was diagnosed with engine failure. The dealer stated that the failure was related to a previous recall associated with the VIN; however, the recall number was not provided. The dealer informed the contact that the engine needed to be replaced. The vehicle was not repaired. The contact was referred to the manufacturer for assistance. The manufacturer was notified of the failure but denied coverage for the repair and alleged that the engine failure was a result of negligence in the maintenance records. The approximate failure mileage was 183,000.

I would like to file a complaint regarding a serious engine issue with my vehicle. At times, when I put the car in reverse, the engine suddenly accelerates on its own without pressing the gas pedal. This unexpected acceleration creates a dangerous situation and increases the risk of an accident. I request that this matter be investigated for potential safety defects to prevent harm to drivers and passengers.

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at an undisclosed speed and making a left turn, the vehicle experienced a loss of motive power. The contact was able to restart the vehicle; however, an abnormal knocking sound was heard, and there was smoke coming from under the hood. The contact was able to drive the vehicle to a nearby residence, where it temporarily remained. The contact attempted to drive the vehicle a few miles to qualify for towing, per the vehicle insurance provider. The vehicle was towed to a local dealer, where it was diagnosed with a rod bearing failure. The vehicle was not repaired due to insufficient engine oil maintenance records. The contact related the failure to NHTSA Campaign Number: 20V746000 (Engine). The manufacturer was made aware of the failure. The failure mileage was approximately 137,600.

While driving home from work after 7 PM on the 215 NB freeway, the oil warning light suddenly illuminated, and the vehicle immediately lost engine power. Within seconds, the engine shut off completely, leaving me unable to accelerate or safely maneuver. I was forced to coast across lanes with no power, creating a significant risk of collision and nearly resulting in a rear-end accident. After the incident, I performed a crankshaft rotation test, which the engine failed, confirming that the crankshaft would not turn. I also verified that the timing chain remained intact. The vehicle has since been inspected by Hyundai technicians, who confirmed the engine failure under Service Campaign 953. Hyundai further communicated via email that my vehicle is eligible under the TXXI Theta Engine Settlement Agreement and expressed a willingness to discuss my recent engine concerns and the details of the settlement.

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the engine started to overheat, with the check engine and temperature warning lights illuminated. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 184,000.

My daughter was driving her 2011 Hyundai Sonata on the freeway at 65mph when the engine light came on and car simultaneously slowed to a stop on 8/21/25 creating significant danger to my daughter and other drivers on the road. There were no prior warnings or indications, and car just had an engine check performed in June 2025. Had it towed to Hyundai on 8/22/25 and Hyundai completed an engine check and it failed. Hyundai told us they'd cover it under the extended warranty if only we could provide complete maintenance records. We were unable to satisfy their record request threshold, as we are not the only owners of this 14-year-old vehicle, so they've requested $10,000 to replace the engine instead. The 2011 Hyundai Sonata is part of the Theta II engine family that has been subject to multiple recalls, class-action lawsuits, and federal investigations due to catastrophic engine failures.

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at 55 MPH and depressing the accelerator pedal, the vehicle hesitated and stopped independently. The contact stated the vehicle went into LIMP Mode independently, with a clinking sound coming from the engine. The contact pulled into a parking lot, awaiting tow truck assistance. Neither a dealer nor an independent mechanic was contacted. The vehicle was towed to an independent mechanic, where the vehicle was inspected and the contact that the lifters needed to be replaced. The vehicle was then towed to the dealer, where it was diagnosed that the lifters, rod bearings, and piston rings needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 15V568000 (ENGINE); however, the VIN was not included in the recall. The manufacturer was notified of the failure and denied the claim. The failure mileage was 167,000.

I own a 2011 Hyundai Sonata with a 2.0 turbocharged engine. The engine failed/presents issues such as loss of power, rattling, oil consumption, and smoking, which resulted in my engine seizing up. This creates a serious safety risk while driving, to now my car no longer operates. I checked NHTSA’s recall database and found no open recalls for my VIN regarding engine replacement, but I believe this engine defect should be investigated for a recall.

I had just started up my vehicle as normal and exited a parking lot when all of a sudden the vehicle switched off and I was able to safely maneuver to the side of the road and it would refuse to start, and there was smoking coming from beside the engine and we were unsure of what it was. I got it towed to a local mechanic and he let me know that it was an engine failure, and that the starter had burned as result of that.

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)

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.

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.

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.

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.

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)

I am filing this complaint regarding a catastrophic engine failure in my 2011 Hyundai Sonata. According to Hyundai’s own documentation, Service Campaign 953, issued in 2018, was never performed on this vehicle. This campaign addresses the risk of connecting rod bearing failure caused by residual metal debris in the crankshaft oil passages.

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

From: [XXX] [XXX] [XXX] I have attempted to make a Better Business Complaint against Hyundai Corporate Office Headquarters 10550 Talbert Ave. Fountain Valley, CA 92708-6031 USA, but I am being blocked from filling out a complaint; attempts to make a complaint against the Hyundai Corporation results in being forwarded to a NULLED screen. NO ONE IS ALLOWED TO FILL OUT A BBB COMPLAINT AGAINST THIS BUSINESS! On [XXX] my wife could have been killed when driving her 2011 Hyundai Sonata (VIN [XXX] ) on the highway when her engine stalled out having to take evasive action not to cause an accident. Note my wife is [XXX]. According to a former Hyundai technician at Schmidt Auto Care (285a Hiawatha Trail, Springboro, OH [937] 514-7860 said there is an open recall (T3G) on this vehicle which is for engine replacement. Schmidt Auto care technician said “the oil ports were drilled wrong in the engine causing them to go out after 100,000 miles.” On March 20, 2025 Ian Clemons Service Advisor at Voss Hyundai (766 Miamisburg – Centerville Road, Centerville, Ohio 45459 [937] 428-2416) stated, “From the pictures of the valve cover it is obvious the engine has had the oil changes because it is super clean, but Hyundai is wanting all the oil change records” (which have been lost in a move). And because of it they won’t replace the engine even though Ian Clemons is advocating for it knowing that it is just thing for Hyundai to do. Case ([XXX] Hyundai Customer Care 1-800-633-5151) Hyundai is trying to hide this recall, calling it an extended warranty on the engine and the public needs to be warned knowing my wife could have been killed by this engine defect and Hyundai needs to make this wrong a right. I ask for your help to resolve this matter of public safety. Thank-you, [XXX] 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 that while driving at various speeds, there was an abnormal knocking sound coming from under the hood. No warning lights were illuminated. In addition, the contact stated that while attempting to start the vehicle, the engine hesitated while turning over. The vehicle was towed to a local dealer, where it was diagnosed, and determined that the long block kit and engine needed to be replaced. The contact was advised that due to the mileage and aftermarket engine in the vehicle, the recall repairs were denied. The contact related the failure to Hyundai Service Campaign: 953. The manufacturer was made aware of the failure. The failure mileage was approximately 216,301.

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)

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 am the proud owner of a 2011 Hyundai Sonata this is my 3rd sonata; we love it due to the worry free long last and warranty. Never had any issues through the years until last night ([XXX]). When getting off from work 6:15PM heading home for about 30 mins. I was driving my car approximately 35 mph when I went to turn a corner suddenly, my car started sputtering, knocking sound and failed to accelerate having traffic behind me not to cause an accident I put my hazard flashers on, and I lean over to the right on grass. Puzzled and scared saying to myself “ What the Hecks” what’s going on. The car parked on the side was having hard time staying on and shut down. I then went and opened the hood to check to make sure nothing was in my engine causing it, everything looked normal except, the smell of oil has a burnt smell to it which means in technical terms it has thrown a rod and bent valves and smell of burned electric. Finally, we called AAA, they advised their busy and it will be about 2 hrs. So, I sat there to wait for AAA. As I sat in my car waiting, I started researching online. I currently do not have any recalls or ever got any notice. I came across there is an active class action lawsuit going on for the rod bearing going out in these models and years. After some time, I called AAA back to get an ETA, they told us they were extremely busy, it would be about another 45 mins. At that time another tow company pulled up and asked if we needed a tow, we didn’t want to wait longer for AAA to get home so decided to have it towed home … totally cost $175. Today I am trying to contact Hyundai to see what we going to do regarding my car and praying it can get fixed on this recall that I had no idea and thanks God, I turned it off my car could start a fire & burned up. I never got notice about recalls for my engine and It’s sad Hyundai does contact owners ahead to let them know about this problem, think about it we are talking about lives. Thank you for taking INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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.