2011 Hyundai Sonata Engine Problems

I test drove the vehicle at an auction, watched several other people test drive the vehicle. Before the auction I test drove it one more time and put my obd scan tool on it to make sure there were no hidden codes or problems. I won the bid,and picked up the vehicle. I drove it approximately 6 miles from the auction and the falshing engine light popped on. I immediately pulled over in heavy freeway traffic. Put my scan tool on it and found out the knock sensor had triggered. The vehicle was shaking and making a terrible racket. It was inoperable in the worst possible spot on Highway 51 during rush hour traffic. I managed to slowing coast down the offramp and roll into a parking lot. I then called Purdy Hyundai and spoke with a service advisor and provided the VIN#. He (Vue Kue) informed me that the vehicle qualified for the recall and warranty work based on exactly that issue. I had the vehicle towed to the Purdy dealership on July 8th 2026. I was told today that it was unlikely that Hyundai would honor the recall because I did not have service records of a vehicle I had owned for 6 miles of driving. I filed a complaint with Hyundai corporate. Claim#43010067 and awaiting the reconciliation of this situation. Of which they appear to to be avoiding.

NHTSA ID

11752063

Incident

Jul 8, 2026

Rod bearing issue due to particles in engine causing engine to not accelerate as normal and jerk when goes over 10 MPH can’t exceed 50 miles causing safety issues and knocking/clicking noise took it to Hyundai and was informed it is apart of the recall but wont replace engine my vehicle has ALL the same issues as the Hyundai recall but my VIN isn’t registered on the site for recall on carfax it shows a pattern of the previous owners being car in for maintenance and engine issues but engine never being replace under recall

NHTSA ID

11747821

Incident

Jun 18, 2026

My 2011 Hyundai Sonata (VIN [XXX] ) was brought to Gateway Hyundai in [XXX] for the mandatory P1326/KSDS engine recall inspection. I had a confirmed appointment on XXX at 7:30 AM. The dealership acknowledged the P1326 code and that the KSDS test was required.Instead of performing the recall, the dealership refused to inspect the vehicle. They contacted a third party who was not in possession of the vehicle and released the vehicle to that person without my authorization. The plates were removed and the vehicle was later sold without my consent. The recall was never performed and the engine defect was never inspected.This is a failure to perform a required safety recall and a violation of chain-of-custody procedures. A vehicle with a known engine failure risk was put back into public circulation without inspection. This creates a safety hazard for the public.I also suffered financial harm including $1,500 in towing, parts, labor, and storage fees. I have a signed tow invoice showing the VIN and the total amount paid.I am requesting that NHTSA investigate Gateway Hyundai’s handling of recall vehicles, review their authorization and release procedures, and take enforcement action if violations are found. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11740786

Incident

Mar 24, 2026

My 2013 Hyundai Sonata suffered engine failure consistent with Hyundai Theta II engine defects. The vehicle became inoperable/unsafe. Hyundai denied warranty coverage despite my maintenance records and documentation.

NHTSA ID

11738819

Incident

Mar 25, 2025

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at 60 MPH, the vehicle lost automotive power. There was no warning light illuminated. The vehicle failed to restart and had to be towed. The vehicle was towed to the dealer, but was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 190,000.

NHTSA ID

11734124

Incident

Apr 27, 2026

Mileage

190,000 mi

On March 18, 2026 I brought my vehicle to AutoNation Hyundai for an oil change and full diagnostic. Your dealership’s own diagnostic report showed no knock sensor code, no engine issues, and no active warning lights. My car was fully drivable when I dropped it off. Within 30 minutes of picking my vehicle up, the check engine light began blinking and the car became completely undrivable. It has not moved since March 20, 2026 at the dealership. The dealership did an additional diagnostic and found a knock sensor that was not there during the first diagnostics and have stated that my engine has too many miles to be covered uder warranty.

NHTSA ID

11728334

Incident

Mar 18, 2026

The vehicle suddenly stopped and died while driving. The mechanic confirms that the engine is gone, contact Hyundai. Ourisman of Rockville and Hyundai Motor America (HMA) refuses to replace the engine for free. The vehicle has now developed a severe engine knock consistent with the well-documented defect affecting Hyundai’s Theta II engines. Hyundai has publicly acknowledged this issue and issued a major recall covering approximately 470,000 vehicles with the following specifications: • Model Years: 2011–2012 • Engines: 2.0L and 2.4L • Manufacturing Period: December 11, 2009 – April 12, 2012 Hyundai and federal regulators identified the safety concern as manufacturing debris that could restrict oil flow to rod bearings. This defect can lead to engine knocking and eventual engine failure. Critically, Hyundai has acknowledged that engine failure may stall the vehicle while driving, significantly increasing the risk of a crash. Hyundai’s official remedy for this defect required dealerships to: • Inspect engines for bearing noise • Replace the engine if necessary • Honor Hyundai’s extended engine warranty of 10 years / 120,000 miles for affected vehicles. This issue has also been the subject of significant litigation, including the class action lawsuit Case No. [XXX], filed January 23, 2018, against Hyundai Motor America (HMA), Kia Motors America, Inc. (KMA), Hyundai Motor Company (HMC), and Kia Motors Corporation (KMC). Despite these well-known issues, Ourisman of Rockville failed to disclose any of the following when selling my daughter's this vehicle: 1. The widespread engine defects associated with the 2011 Hyundai Sonata. 2. The recall and safety concerns related to debris restricting oil flow to rod bearings. 3. The extended Hyundai engine warranty covering affected vehicles up to 120,000 miles. This omission is particularly concerning because this defect presents a serious safety hazard and a clear and present danger. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.

NHTSA ID

11726946

Incident

Mar 13, 2026

My 2011 Hyundai Sonata experienced sudden engine failure and the engine is now locked up. The vehicle became inoperable and had to be taken to a Hyundai dealership. The dealership confirmed the engine is locked and not drivable. Hyundai denied the engine replacement claim stating the vehicle has A04/A08 branding indicating the engine originates from a scrapped or rebuilt vehicle. However, Hyundai refused to provide any documentation supporting this claim. They also refused to verify the engine serial number against the VIN to confirm whether the engine is original to the vehicle. A NMVTIS vehicle history report shows the title status as ACTIVE with no salvage, junk, or rebuilt branding. Despite this, Hyundai continues to deny the claim without documentation. This vehicle contains the Hyundai Theta II engine that has been the subject of recalls and settlement actions related to premature engine failure. The failure pattern in this case matches the known defect where engines seize or lock up unexpectedly.

NHTSA ID

11724779

Incident

Feb 5, 2026

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.

NHTSA ID

11713510

Incident

Aug 1, 2025

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving approximately 65 - 70 MPH, there was a grinding sensation coming from the front wheels, and the grinding sensation was felt in the steering wheel. The vehicle was taken to the dealer, who diagnosed that the rod bearings and hubs had failed, causing the grinding sound. The contact was informed that the rod bearings and hubs needed to be replaced. The vehicle was towed to a certified mechanic, and the vehicle was repaired. The contact stated that while driving at various speeds the following day, there was a loud grinding sound coming from the vehicle. The sound also occurred while the vehicle was parked. While attempting to accelerate from 25 - 35 MPH, the engine started knocking, and the vehicle clunked and jerked. The vehicle decelerated, and the contact pulled over to the side of the road. The contact became aware that the accelerator pedal was not operating as needed. While on the side of the road, the contact turned off the vehicle and attempted to restart the vehicle; however, the vehicle failed to restart. The vehicle was towed to a certified mechanic, who diagnosed that the engine had failed, and the mechanic recommended the engine replacement. The vehicle was not repaired. The vehicle was towed to a different dealer, Capital Hyundai of Greensboro (801 E Bessemer Ave, Greensboro, NC 27405), and the contact was informed of NHTSA Campaign Number: 15V568000 (Engine). The vehicle was not repaired because the manufacturer stated that the maintenance history was not satisfactory enough to warrant an engine replacement. The failure mileage was approximately 138,000.

NHTSA ID

11712626

Incident

Dec 18, 2025

Mileage

138,000 mi

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.

NHTSA ID

11710623

Incident

Jan 13, 2026

Mileage

183,000 mi

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.

NHTSA ID

11710036

Incident

Nov 15, 2025

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.

NHTSA ID

11701548

Incident

Nov 2, 2025

Mileage

137,600 mi

The vehicle experiences a recurring defect where the brake light turns on suddenly and the engine shuts off while driving. The failure appears related to the braking system (brake switch circuit), electrical system (CAN-bus/ECU communication), and engine control (shutdown/stall). The system remains installed and is available for inspection upon request. The shutdown poses a serious safety risk, including possible rear-end collision or loss of power in traffic. The problem has occurred multiple times. The dealership inspected the vehicle briefly but failed to diagnose or document the defect and returned the vehicle within hours, stating “it shouldn’t be a problem,” even though the issue continues. Hyundai has refused to provide recall documentation or authorize a re-inspection. The only warnings prior to shutoff are the sudden activation of the brake warning light just before the engine cuts off.

NHTSA ID

11700240

Incident

Nov 1, 2025

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.

NHTSA ID

11699615

Incident

Sep 30, 2025

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.

NHTSA ID

11697316

Incident

Sep 23, 2025

Good day, please note that most of my communication with Hyundai has been over the phone. I sent one an email shortly after the event, and after following up on the phone, I received this following string separately. I can forward you more along the way, but Hyundai is in possession of the call recordings. I was hoping they would cover my repairs, my engine had a lifetime warranty, but during this process I learned that there was a recall for this car that I was never aware of as the new owner. I needed a software update to get any repairs covered. Please reach out to me for more info!

NHTSA ID

11696471

Incident

Oct 8, 2025

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.

NHTSA ID

11696100

Incident

Oct 28, 2025

Mileage

184,000 mi

In summer of 2023 my car 2011 Sonata Hybrid quit running and would not start. My granddaughter had used the car to go to Oklahoma City for a tennis tournament. Her life was at risk because she was coming back in the evening and was alone. The next day I had the car towed to Ada Oklahoma and then called dealership and had it towed to Ardmore, Oklahoma where I had purchased the car new in 2011. The car was at the dealership for 6 months. The vehicle was inspected at the dealership. There were no warning lights or symptoms of the failure prior to the breakdown. I am an 80 year old female that knows nothing about a car engine and they talked to me like I was a mechanic. I still do not know why my claim was denied but was told that I did not have a claim. I had to rent a car to get to work for several months and was out the money to have my car towed 2 times. Not to mention the strain of being without my car for 6-7 months. I finally just gave up until I read about all these other people having trouble with Hyundai also.

NHTSA ID

11695234

Incident

Jun 10, 2023

I bought this car from someone in April of 2024 and the person who i bought it from said everything was perfectly fine, they brought it to the Hyundai dealership and according to the mechanic there the engine was fine….i have taken care of the engine since i bought the car, kept up with oil changes and everything….until a few days ago when the whole thing ceased up on me while driving down the road to my sons school. I wasnt going fast either, the speed limit is 40mph where i was when it happened, but I’m glad i have quick reflexes because otherwise we would have wrecked the car. Everything shut off on me and now its knocking. There is alot of metal shavings in my oil and my mechanic tried to drain it a few times to get the debris out of the oil but it does no good.

NHTSA ID

11694680

Incident

Oct 19, 2025

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.

NHTSA ID

11693138

Incident

Aug 22, 2025

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.

NHTSA ID

11691138

Incident

Sep 17, 2025

Mileage

216,301 mi

The affected component is the engine/rod bearing (Theta II 2.4L). My 2011 Hyundai Sonata stalled and the engine locked up twice in live traffic (March 2025 and July 2025). The vehicle is available for inspection if needed. This created a serious safety risk to me and others on the road, as the stall occurred on [XXX] at highway speeds. This failure could have been catastrophic had it happened on the DC/Baltimore Beltway or another high-traffic roadway. Hyundai’s system shows Recall 132 was marked complete at very low mileage (around 32,000 miles), but my vehicle later developed oil consumption and stalling consistent with rod bearing failure. Capitol Heights Hyundai noted a warranty pre-authorization (PA) in March 2025 and told me Hyundai needed my mailing address “for the claim,” but later said it was a typo and that no record exists. The dealership charged me for a diagnostic but did not inspect the vehicle for rod bearing failure, despite symptoms consistent with Recall 132. Annapolis Hyundai, where the car was purchased as a CPO, has admitted they have no documentation that Recall 132 was ever performed (no repair order, mileage, or technician notes). Yet Hyundai’s system shows Recall 132 marked “complete.” Without proof that the KSDS software or bearing inspection was done, I belive this recall should be considered open. Hyundai Consumer Affairs has stated that I must pay for towing and diagnosis before they will investigate, with possible reimbursement later. This conflicts with federal law (49 U.S.C. § 30120), which requires recall diagnosis and repair at no cost to the consumer. Prior to the failures, my vehicle had a history of oil consumption and “no oil on dipstick” findings, which are known precursors to rod bearing failure. No warning lamps appeared before the stalls. I am requesting NHTSA’s assistance in requiring Hyundai to provide documentation or reopen Recall 132 and perform a no-cost inspection/repair to ensure this vehicle is safe to operate INFORMATION REDACTED PURSUANT TO THE FREEDOM OF

NHTSA ID

11690938

Incident

Mar 11, 2025

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 INFO

NHTSA ID

11690722

Incident

Sep 30, 2025

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.

NHTSA ID

11690300

Incident

Aug 28, 2025

Mileage

167,000 mi