Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2011 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2011 Hyundai Sonata GLS. The contact stated while driving at 20 mph and making a turn, all warning lights started flashing and the vehicle began to make an abnormal knocking noise. The contact was able to safely stop the vehicle as he noticed that smoke was coming from under the vehicle. The smoke stopped on its own as the engine was turned off. The contact had the vehicle towed to a dealer where it was diagnosed with needing the ECM cluster update (Software) which contributed to the engine failure. The contact stated that the dealer informed him that the engine also needed to be replaced. The vehicle was not repaired as the dealer said that the engine replacement was not covered under warranty. The contact stated that the failure was related to a manufacturer warranty recall number: 953. The manufacturer was informed of the failure however no assistance was offered. …
The contact owned a 2011 Hyundai Sonata. The contact initially stated that while driving at various speeds, an abnormal, knocking noise would emit from the engine. The contact had taken the vehicle to the dealer where a knock sensor test was performed and the contact had the engine replaced under warranty. A few months later while driving at night at 35 MPH, smoke(color unknown) began to emit from the vehicle without warning as he noticed his feet getting warm. The contact then saw flames emit from the vehicle and immediately pulled over. The fire department was called to the scene and extinguished the fire(fire report unknown). Police also arrived at the scene and a police report was filed. No injuries were reported at the scene. The vehicle was totaled and towed to an independent body shop. …
The contact owned a 2011 Hyundai Sonata The contact stated that while driving, the accelerator pedal locked up and the transmission was slipping. Smoke was detected and fire emerging from the engine. The check engine warning indicator light was illuminated. There were no reported injuries. A Police report was filed. The fire department extinguished the fire. The vehicle was towed to an unknown location. The local dealer was not contacted. The vehicle was not diagnosed or repaired The manufacturer was not notified of the failure. The insurance company deemed the vehicle a total loss. The failure mileage was 187,479. The VIN was not available.
The contact owned a 2011 Hyundai Sonata. The contact stated that he sold the vehicle to a lady yesterday, and while the lady was driving with her daughter at an undisclosed speed at around 9:00 p.m., the vehicle stalled and the engine caught fire. No warning lights were illuminated. The fire department extinguished the fire. The vehicle was not towed. There were no injuries. No police report was filed. The vehicle was not deemed totaled by the insurance company. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 140,000.
The contact owns a 2011 Hyundai Sonata. The contact stated that the vehicle would not start after several attempts. Several unknown warning lights were illuminated. The vehicle was towed to an independent mechanic who did not diagnose the vehicle but advised the contact that the failure was related to an unknown recall. The manufacturer was notified of the failure and informed the contact that her vehicle was included in NHTSA Campaign Number: 15V568000 (Engine). The vehicle was towed to the dealer who advised the contact that the parts for the recall repair were not yet available. The contact stated that the vehicle had remained at the dealer since October. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. …
The contact owned a 2011 Hyundai Sonata. The contact stated while driving at 50 MPH, another vehicle crashed into the rear end of the vehicle. The contact depressed the brake pedal and the vehicle skidded and stopped. The air bags failed to deploy. The contact was able to drive the vehicle to her residence and parked the vehicle. The contact then sought medical assistance and was informed that she had sustained a left shoulder rotator cuff tear. A police report was filed. The vehicle was taken to the dealer where it was diagnosed that the air bags failed to engage and did not need to be reset. The vehicle was then taken to an auto collision mechanic where it was repaired. The contact stated while driving at an undisclosed speed, another vehicle crashed into the driver's side of the vehicle. The contact was thrown to the right and to the driver's side door. The air bags failed to deploy. …
The contact's daughter owns a 2011 Hyundai Sonata. The contact stated while his daughter was driving 40 MPH, the engine seized. The contact's daughter was able to pull to the side of the road. The vehicle failed to restart and was towed to the dealer, where it was diagnosed that there were metal shavings in the engine. The dealer informed the contact that the engine was replaced with a rebuilt engine. The contact stated while his daughter was driving 50 MPH, the vehicle shuddered, and the engine seized a second time at 96,000 miles. The contact's daughter was able to pull to the side of the road. The vehicle was towed to the dealer, who informed the contact that there was no oil in the vehicle. The dealer performed an oil change on the vehicle, and the vehicle restarted. The check engine warning light was illuminated. The failure recurred a week later and there was no oil in the engine. …
The contact owns a 2011 Hyundai Sonata. The contact stated while driving approximately 45 MPH, the instrument cluster started showing numerous warning lights. The contact stated that the vehicle was losing motive power. The contact depressed the accelerator pedal; however, the vehicle failed to respond as needed. The contact stated that the vehicle stalled and lost power steering and braking functionality. The contact was able to coast to the side of the road and turned off the vehicle. The contact started smelling a burning odor in the cabin of the vehicle and saw smoke coming from under the hood. The contact exited the vehicle and opened the hood, and a large cloud of smoke was released. There were no flames, but the contact smelled the odor of melted plastic and rubber. The Fire Department was called but the vehicle did not catch on fire. …
Driving from home to a shopping center, approximately 25 miles, I did not observe any unusual noises nor smoke nor dashboard warning lights. Once I parked and shut off the engine in the shopping center parking lot, I observed a small amount of thick, white smoke coming from the hood on the front passenger side of my car, and then the smoke abruptly stopped. I was concerned enough that I decided I should probably move my car to a parking space a bit further away from the store I planned to go into in order to be further away from other vehicles. I started the engine again, and once again, no smoke nor unusual noises nor warning lights. I drove around to the next parking aisle and parked in a different parking space. Once I turned off the engine again, the smoke then immediately started from the right side of the hood again and quickly smoke started coming from the left side of the hood. …
The contact owns a 2011 Hyundai Sonata. The contact stated that while driving approximately 35-40 MPH, the vehicle lost motive power and stalled. The vehicle was towed to a certified mechanic who diagnosed that cylinder #4 had failed causing the engine to seize. The engine was replaced with a used engine. The engine was replaced at approximately 109,000 miles. The contact stated that while driving for approximately 45 minutes, the contact noticed that the vehicle would not exceed 60 MPH. The check engine warning light started flashing. The contact continued to drive the vehicle to a rest stop. After being parked for a while and then restarting the vehicle, several unknown warning lights illuminated. The vehicle then failed to exceed 45 MPH. The vehicle was towed to the dealer to be diagnosed. The contact was informed that the engine had seized due to a lack of engine oil. …
Related recalls
Engine
Hyundai Motor America (Hyundai) is recalling certain 2011-2014 Sonata and 2013-2014 Santa Fe Sport vehicles previously repaired under recall numbers 15V-568 and 17V-226. The high pressure fuel pipe that connects to the fuel pump outlet may have been damaged, misaligned, or improperly torqued during the engine replacement…
Remedy: Hyundai will notify owners, and dealers will inspect and replace the fuel pipe, as necessary, free of charge. The recall began March 1, 2019. Owners may contact Hyundai customer service at 1-855-371-9460.
Engine
Hyundai Motor America (Hyundai) is recalling certain model year 2011-2012 Sonata vehicles manufactured December 11, 2009, to April 12, 2012 at Hyundai Motor Manufacturing Alabama and equipped with either a 2.0 liter or 2.4 liter Gasoline Direct injection engine.
Remedy: Hyundai will notify owners, and dealers will inspect the vehicles and replace the engine assembly, as necessary, free of charge.
NHTSA investigations
Scope and Timeliness
NHTSA opened Recall Query (RQ) 17-004 to investigate the timeliness and scope of Hyundai?s Theta II GDI engine recalls (Recall Nos. 15V-568 and 17V-226), and Hyundai?s compliance with reporting requirements. On November 23, 2020, the Agency entered into a Consent Order with Hyundai to administratively resolve NHTSA?s assertions of violations of law in connection with RQ17-004.
Engine Fires
On March 29, 2019, the Office of Defects Investigation (ODI) opened two Preliminary Evaluations (PE19-003 on Hyundai and PE19-004 on Kia) to broadly investigate incidents of non-crash fires (regardless of origin or operational status of the vehicle) on various model year Hyundai and Kia vehicles.
Loss of Motive Power
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021.
Engine complaints in other Sonata years
Frequently asked questions
How common are engine problems on the 2011 Hyundai Sonata?
NHTSA has 1,012 complaints about the engine & cooling of the 2011 Hyundai Sonata, 30% of the model year's 3,378 complaints. The component named most often is engine (9 mentions).
Is there a recall for 2011 Hyundai Sonata engine problems?
Yes — NHTSA recall 18V-934 (engine, Dec 28, 2018); NHTSA recall 15V-568 (engine, Sep 10, 2015). Recall repairs are free at authorized dealers.
At what mileage do 2011 Hyundai Sonata engine problems start?
Half of the complaints with a recorded mileage happened before about 96,000 miles, and 9% before 25,000 miles.
Is it dangerous?
Owners linked 21 crashes, 86 fires and 16 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.