2012 Hyundai Sonata: engine knocking or ticking

Filed Jul 31, 2026 · Engine · 100,000 miles · DE

The contact owns a 2012 Hyundai Sonata. The contact stated that while driving at 30 MPH, the check engine warning light illuminated, the engine started knocking, and smoke emitted from under the hood. The contact decelerated to approximately 15 MPH and drove to her nearby residence. Upon inspection, the contact observed green fluid under the hood. The vehicle was towed to an independent mechanic, where it was diagnosed that the engine had failed and the head gasket was blown. The mechanic informed the contact that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 100,000.

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 16, 2026 · Airbags, Engine · VA

Knock sensor needs to be replaced upon evaluation of an inspection on March 27, 2026. It failed a mission codes and upon my understanding the knock sensor one circuit range performance pink wonder single sensor is an engine failure as well as I did an ODB test myself on May 19 of 2026 for the Knox sensor as well and the check engine dominator reading at 2111 the the code indicated that bank one Knox and electrical circuit was out of it upper range or had it perform problem for a predetermined period of time and the code is P0326 and the secondary DTC is a combustion vibration sensor a circuit range performance which affects the powertrain. Also, I have switches with the electrical features in the vehicle as far as the ABS and the steering wheel controls and glitching for the cigarette adapter and plug-in area as well on top of the rear passenger side window, having issues with going up and down.

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 May 2, 2026 · Engine, Transmission · AL

p1326, rod bearing failure and seizure of motor without warning.

Filed Apr 2, 2026 · Engine · AZ

I purchased a used 2012 Hyundai Sonata. Within about 2 weeks it broke down while I was in the far left lane of the freeway. The car suddenly stopped accelerating and made a very loud knocking noise. Thankfully I was able to put on my hazards and make it to the right shoulder without getting into an accident but as soon as I pulled over it shut off and the panel lights all came on. Evidently there was a recall on an engine rod and the previous owners advised they were not aware of it. Hyundai has declined the repair on the recalled engine several times and their reasons keep changing. First they said I was missing records (admittedly I was missing one record but then provided it to them), then they stated excessive neglect due to the condition of the valve train (I saw pics of the valve train and is in good condition), and now they state because the KSDS wasn't installed. From what I understand, being the second owner, if I can prove the upkeep of the vehicle the extended waranty should cover the repair. I even have the letter from the car mechanic stating the vehicle was maintained and in good condition. It seems a lot of good people are getting declined for repairs on these faulty engines. I have many more documents I could provide showing all of the services done and communications with the company. Due to the size limit I included these ones for your review. Thank you so much for any help you can provide.

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 Mar 23, 2026 · Electrical, Engine · GA

While I was driving my car wouldn’t go no higher than 60mph and kept dropping speed but I came to a stop and when I stopped the car was smoking. I heard knocking noise and rumbling noise on the passenger side. It wouldn’t start again

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 Oct 26, 2025 · Airbags, Engine · VA

My 2012 Hyundai Sonata (VIN: [XXX] ) experienced complete engine failure at 241,433 miles on August 7, 2025. The failure aligns with known safety defect symptoms described under the federal safety agency Recall Campaign 15V568000 and 17V226000, which cite premature bearing wear due to metal debris during engine manufacturing. My vehicle had previously received the knock sensor update under Campaign T3G and failed the BCT (bearing clearance test), confirming bearing damage. Despite this, Hyundai denied my engine replacement claim, stating the issue was related to a fuel pipe and not a rod bearing issue—this is contrary to their own recall documentation and dealer diagnosis. Hyundai continues to deny engine replacement, in violation of their federal recall obligations under 49 U.S.C. §30120. Their refusal endangers public safety by ignoring engine failures that can lead to stalling and crashes. I request the federal safety agency intervention to compel Hyundai Motor America to comply with federal law and perform the necessary recall repairs on my vehicle. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 1, 2025 · Brakes, Engine · 100,000 miles · NV

The contact owns a 2012 Hyundai Sonata. The contact received notification of the federal safety agency Campaign Number: 18V934000 (Engine, Fuel System, Gasoline). The contact stated that while driving 20 MPH, the vehicle stalled. There was an abnormal knocking sound coming from the vehicle. While driving at an undisclosed speed, the vehicle stalled after five minutes. The engine and the ABS warning lights were illuminated. The vehicle was towed to the residence. The contact called the local dealer and was informed that the maintenance records were needed. The contact was using an independent mechanic for maintenance and did not have the records. The vehicle was not diagnosed or repaired. The manufacturer was contacted and opened a case. The failure mileage was approximately 100,000.