2012 Hyundai Sonata: sudden loss of power

Filed Oct 27, 2026 · Engine · NY

On August 19, 2026, at 76,170 miles, the engine in a 2012 Hyundai Sonata GLS suddenly lost power and shut off while the vehicle was moving on gas station property. The driver had traveled approximately 10 feet before the engine stopped. Repeated attempts to restart were unsuccessful; the engine would not crank. The driver shifted into neutral and pushed the vehicle to a safe location. Before the failure, the vehicle was running smoothly, with no warning lights, warning messages, unusual noises, or other symptoms. There was no collision, injury, smoke, or fire. The sudden, unannounced loss of propulsion created a safety concern because the vehicle could no longer move under its own power. Fortunately, the driver was still on the gas station property and was not blocking traffic. An independent repair shop inspected the vehicle and confirmed that the engine was mechanically locked up. The vehicle was subsequently taken to an authorized Hyundai dealership for inspection. The dealership’s service adviser reported lower rod-bearing failure. Hyundai later denied engine-replacement coverage, citing neglect and missing maintenance records. That denial is being disputed through BBB arbitration. The vehicle had received an oil and filter change and a mechanical inspection on August 4, 2026, at 74,548 miles—15 days and 1,622 miles before the failure. The vehicle remains at the Hyundai dealership, and the engine is available for inspection upon request. The exact underlying cause of the reported bearing failure is UNKNOWN.

Filed Jul 15, 2026 · Engine · VA

As I was merging onto the interstate I put my foot on the gas pedal to give it a little more gas then usual to get pulled out and all of a sudden all the lights on the dash board illuminated and it slowly lost all power I was able to move it out of the road ... There was no loud ,knocking or ticking noises prior to this happening there was no type of any kind of warning .. my car is the push start button so after the car died completely I hit the push button and all the lights on the dash came on the radio worked and everything else seemed to be working it was when I went to put my foot on the brake to start it it would do nothing it would not start at all .. I was still able to put it in neutral even after the incident happened . I had it towed t Hyundai of Bristol to have it inspected well they did verifi that the engine was locked up but failed to give me any information on the test they ran or how they keep it was locked up and what locked it up so then they have my car over a week and they tell me I need a new engine but then contact me to tell ke that HMA refused to replace the engine on warranty and I had the campaign 953 completed the knox sensor thing before my car broke down so then I had to pay for towing once again out of my pocket to go pick the car from their dealership so when I got there to get my car the service was not that great and my car was in a mess very uncalled for the battery to the car was completely dead with that being said we had to use another battery to just get it turned on to even put it in neutral well then fuel started spraying from the fuel line , the engine cover was left off right along with engine mount was taken off and they even took the belt off there were bolts laying all over my hood of my car and I'm pretty sure we lost a few transporting the car back ..their service they provided was not business/professional behavior and very disrespectful at that .. returning my car in that condition was very unnecessary

Filed Jun 30, 2026 · Engine · OH

Around the end of May 2026, my vehicle stalled without warning while traveling at highway speed. The engine light and EPS warning light illuminated simultaneously. The engine cranks but will not start. The vehicle was towed to a Hyundai dealership on June 15, 2026 where the engine failure was confirmed. My safety was directly at risk. The vehicle lost power on an active highway with no warning, creating a collision hazard for myself and other drivers. The failure has been confirmed by the dealership. Hyundai Motor America acknowledged the engine failure falls under the TXXI Settlement Agreement and offered a buyback or cash settlement. However, Hyundai has had physical possession of my vehicle since June 15, 2026 and has repeatedly failed to provide a written buyback offer despite multiple commitments to do so. Prior warning signs included the engine and EPS lights activating at the moment of failure. No prior warning lamps appeared before that day. The vehicle has 2 open safety recalls as of the date of purchase in November 2025.

Filed Jun 6, 2026 · Engine · VA

Vehicle experienced sudden loss of motive power while merging onto interstate I accelerated to enter traffic and all dashboard warning lights illuminated at once. Engine shut off immediately with no prior knocking,smoke, or warning. Car coasted to shoulder with complete loss of power steering and power brakes. After incident vehicle will not crank or restart , push -button start activates accessories but engine does not turn over when brake is pressed. Vehicle has Campaign 953\Knock Sensor Detection system update completed on October 14 2020. This failure matches the federal safety agency PE-18-003 and Hyundai TSB 22 -EM-003H for Theta II Engine connecting rod bearing failure.This is a known safety defect causing sudden engine stall at highway speeds .. Dealer inspection is pending Vehicle is currently inoperable...

Filed Jun 5, 2026 · Engine · VA

While merging onto the interstate my vehicle suffered sudden loss of motive power. All dash lights illuminated ,engine shut off instantly with no prior knock or warning.vehicle will not crank or restart.push button start activates accessories only .This matches TSB 22-EM-003H for connecting rod bearing seizure.No crash occured because I was able to coast to shoulder but loss of power steering/brakes at highway speed created a dangerous situation.

Filed Mar 24, 2026 · Engine · IN

While driving, the vehicle experienced sudden engine malfunction. The car entered limp mode, lost power, and produced a loud knocking noise from the engine. The failure occurred without warning and created a safety risk because the vehicle could not accelerate properly in traffic. This increased the risk of being rear-ended or unable to move out of dangerous situations. The issue appears to involve the engine (possible internal failure). The vehicle is currently at an authorized dealership and is available for inspection upon request. The problem has been confirmed by the dealership during inspection. The vehicle has been under diagnosis for over three weeks. There were no prior major warning signs before the failure. At the time of the incident, the vehicle suddenly lost performance, entered limp mode, and began making abnormal engine noise. This issue is consistent with widely reported engine defects in similar vehicles. Despite this, the manufacturer has denied coverage and attributed the issue to maintenance, even though regular maintenance was performed. This is a serious safety concern due to sudden loss of power while driving.

Filed Nov 18, 2025 · Engine · NC

The engine in my Hyundai Sonata (replacement engine VIN [XXX] ) experienced a complete internal failure. The component that failed is the 2.4L Theta II GDI engine, which is known for issues related to metal debris, oil restriction, rod bearing wear, and resulting piston and compression failure. The failed engine is currently at the dealership (Carolina Hyundai) and is available for inspection upon request. My safety was put at risk because the engine lost power unexpectedly, ran extremely rough, and became inoperable. A sudden loss of power while driving could have caused a crash, especially in traffic situations. The problem has been reproduced and confirmed by the dealership. They performed a compression test and found all cylinders at extremely low PSI (35–45 psi). The dealer stated the engine cannot perform the required bearing clearance test due to the level of internal damage. Hyundai Corporate initially declined assistance, calling it a piston failure, but the symptoms and damage are consistent with the known Theta II recall issues. The vehicle has been inspected by the dealership, and all diagnostic information has been submitted to Hyundai under PA Reference #XXX. Hyundai Corporate has not yet responded to me with a case manager. Before the engine failure, the vehicle had rough running and loss of power, but no warning lights or messages illuminated on the dashboard. Symptoms appeared shortly before the engine became undriveable. Based on the dealer’s findings and the engine’s known defect history, it is my assessment that the failure is related to the same issues described in Hyundai’s Theta II engine recall (Campaign 132). INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 23, 2025 · Engine · PA

While driving on the highway with my two minor children, my vehicle suddenly shut off without warning. I lost power in the middle of traffic, which was extremely dangerous — we were nearly rear-ended and had to coast to the shoulder. The check engine light had been on for some time prior to the incident, but there were no other warning messages. After being towed, the car would not start again, even after attempting to jump-start it. A mechanic inspected it and believes the engine is seized. I later discovered that my 2012 Sonata is equipped with the Theta II engine, which is known for sudden failure due to oil starvation or bearing wear. Although there are no current recalls on my VIN, the symptoms are consistent with the known Theta II engine defect. This situation put me and my children at serious risk, and I believe this failure needs to be addressed as a safety issue.

Filed Feb 27, 2025 · Electrical, Engine · OH

When driving. Slow down to turn or to use round about car goes into EV. When i go to accelerate the gas motor will not re engage and the hybrid alarm system will go off. I lose all power to go any where. I have to pull over shut my car off give it a min then restart so the motor will come back on so i can drive again. I have to do this mulitple time in a 20 mile drive.

Filed Sep 26, 2024 · Brakes · CA

The grid warning light is coming on and telling me to stop the car. When this occurs the car will lose power and the brakes will start making a grinding noise. My safety was at risk when I was driving on [XXX], Chula Vista, California by Southwestern Community College approaching behind cars at a red light intersection on the second lane to the right going east and the warning light came on. The car started making a grinding noise and to lose power. The intersection was busy and I was barely able to get the vehicle to the right lane to get out of the way of traffic going east. I was blocking the right turn lane onto [XXX] in Chula Vista, Ca I took the vehicle to the dealer and has been confirmed. It first appeared approximately in July / August of 2023. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 18, 2024 · Airbags, Engine · TX · fire

Airbag clock springs module malfunction disabling emergency deployment of the driver’s side airbag in the event of a collision. My 2012 Hyundai Sonata 2.0 Turbo with 93,336 miles on it, ending seized up going at highway speed causing instant and complete loss of power. Smoke started coming out from under the front engine compartment hood making me think the car was on fire. Trying to get the car manuvered off the highway and over to the right side of the road I was almost involved in a collision with other traffic. I was scared almost to death. Hyundai Motor America is now refusing to repair my vehicle even though it is covered under their extend warranty.

Filed Mar 12, 2024 · Engine · 195,000 miles · VA

The contact owns a 2012 Hyundai Sonata. The contact stated that while his daughter was driving at 65 MPH, an abnormal knocking noise began to emit from the vehicle as the check engine light appeared on the instrument panel. The vehicle began to lose power as the contact's daughter coasted the vehicle into a parking lot. Due to the failure, the vehicle was towed to the contact's residence. Upon investigation, the contact discovered the federal safety agency Campaign Number: 15V568000 (Engine) which was linked to the failure. Neither the dealer nor the manufacturer had been notified of the failure. The vehicle had yet to be repaired. The failure mileage was approximately 195,000.