2011 HYUNDAI SONATA Complaints

CRUISE controldoesnt work due to design defect dirt getting in and stopping the function.

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.

The contact owns a 2011 Hyundai Sonata. The contact stated that while attempting to start the vehicle, the vehicle failed to start as intended, and the contact noticed a strong fuel odor coming from underneath the hood. Upon inspecting underneath the hood, the contact noticed a leak. An independent mechanic diagnosed the vehicle and determined that the fuel line was leaking. The vehicle was not repaired. The contact related the failure to an unknown recall. The manufacturer was contacted, but only the automated system was available. The failure mileage was unknown.

There was no accident .Airbag light on the dash, on the driver side, remains on at all times. The airbag indicator on the passenger side says off. Dashboard has completely cracked, both sides and the center. Unknown incidents- I don’t know of any incidents.

The contact owns a 2011 Hyundai Sonata. The contact stated that while the vehicle was parked, an inspection revealed that the rear frame of the vehicle, located near the passenger’s side, was severely corroded. The dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and a case was opened. The approximate failure mileage was 148,757.

The Vehicle: "I have a 2011–2014 Hyundai Sonata with massive underbody rust." The Failed Fix: "Service Campaign 946 was completed on this car in 2017, but it did not work. The rust is now worse." The Safety Risk: "The structural metal is so rusty that I am afraid it will snap while I am driving. This makes the car unsafe." Hyundai is refusing to fix it because the car has a 'branded' (abandoned) title, even though the structural safety issue is still there."

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the brake warning light illuminated, and the vehicle shut off. The vehicle was taken to the dealer, where it was confirmed that the failure was due to an unrepaired recall. The contact received notification of NHTSA Campaign Number: 23V651000 (Service Brakes, Hydraulic). The repair was performed. The failure reoccurred. The dealer was made aware of the failure; however, the failure was not duplicated. The contact was informed that the recall was closed. The vehicle was taken to an alternate dealer, where it was diagnosed with a failed hydraulic ABS booster sensor. The contact was provided DTC: C1237/HPU. The contact was informed that the hydraulic ABS booster sensor needed to be replaced. The vehicle was repaired. The vehicle was released to the contact; however, the failure reoccurred. The contact stated that the ABS warning light illuminated and then went off. The manufacturer was made aware of the failure, and a case was filed. The contact was advised to take the vehicle for a second inspection. The dealer declined to perform the second inspection. The contact was informed that the repair was not associated with the recall repair. In addition, the contact referenced several unknown recalls; however, the contact was informed that the repair was not related to a recall. The failure mileage was approximately 149,000.

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.

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.

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.