My 2015 Sonata will stall out dropping speeds to 12-24 when i slightly merge, when I turn ect. Then it won-??t accelerate for what seems like 10 minutes realistically 2 minutes maybe 3 Then will slowly regain speed. I-??ve almost wrecked twice Share care with daughter and she-??s been victim to it way way more. This is scary and Hyundai won-??t stay behind their product Local dealership won-??t fix recalls so we have to go over 120 miles for repairs. The recall isn-??t even for transmission engine

- Guntown, MS, USA

on the day of Friday may 16, 2025. I was returning from work on 35 going south in Dallas, Tx. the engine seized leaving my vehicle in a neutral state. I was in the furthest left lane(passing lane). Lord willing I had enough motion to safely exit on Illinois ave without injury of myself or others. the starter could no longer turn the flywheel indicating to me that the crank shaft had seized. i inspected the oil; it was low but no warning light ever came on(the dealer recently stated the oil was fine when they performed a multipoint inspection(5/10/25) when I went in for the gov mandated theft software update as my car had recently been attempted to be stolen), no sort of warning light came on, nor did the ksds update do anything just like countless other kia/hyundai owners who's engine seized on the interstate. I towed the car to clay Cooley Hyundai Dallas because my research indicated that theta 2 engines had government mandated extended warranty even for subsequent owners however as I didnt drive it often & had only replaced the oil(I change every 3k and was soon to do another) once, because I've only owned car for around 6k miles(purchased 10/30/24 I think)before it seized. Hyundai denied txxi claim, stating engine didn't seize due to connecting rod bearing failure, further stating, it was neglect. they said my valve train look terrible. well its going appear so as the theta 2 was inherently known for poor oil flow, major oil consumption, rough crankshafts & improper deburring, all of which lead to premature ware of internals&seizing. also they stated there weren't enough oil changes on the carfax in general, well not all shops report auto service so there isn't going to always be records. furthermore they were failing even in the range of 25k-60k, indicating they were still failing with records of timely service. to my knowledge they didnt perform what I believe they're Mandated to do i.e vid/pic evidence that they cant turn the crank, a bct test, oil level etc.

- Dallas, TX, USA

The vehicle experienced sudden engine failure due to rod bearing damage. The engine seized without warning and required towing. A Hyundai dealership confirmed rod bearing failure consistent with known Theta engine defects. Hyundai denied engine replacement coverage because a software update (Campaign 953 / KSDS) was not completed; however, I never received notice of this campaign. The campaign does not appear on the NHTSA VIN lookup for my vehicle, and it was still listed as outstanding in Hyundai-??s system at the time of failure. The sudden engine failure created a safety risk due to loss of power.

- Tracy, CA, USA

i've had my 2015 hyundai sonata now for A year. i took it to the hyundai place to have recalls on the security fixed. and told them about the valve cover gasket leaking. they said they fixed it. however every since i took it to the dealership i have had nothing but problems. my car makes a rattling noise when i accelerate, i smell a strong gas smell occasionally at random times but always while driving. my driver brake light has never worked, my driver headlight keeps blowing, my airbag light is now coming on randomly, my car has a bag vibration while going down the road, when i let off the gas it stops and i have replaced tires and still it won't go away no matter what i have done to fix it, and there has been many times after i return home the smell of something burning as off something is on fire is coming from my car. i have even been in panick thinking something today home was on fire but the smell was coming from my car. and others have even stated they smelled it as well. i've already taken out two loans to fix the valve cover gasket and the fuel pump filter, i can not keep taking out loans to fix problems that appears to be problems from the manufacturer and same problems others have had due to malfunctioning issues. i have children that ride in my car, i would hate for someone to get hurt or worse bc of manufacturing problems. then hyundai would have a bigger problem on their hands.

- Hephzibah, GA, USA

The engine has failed and I was then i formed that there was a arbitration settlement that Hyundai were replacing engines under this settlement. I was not informed of this and now they are saying it has expired. I would like for them to honor this and repair my engine under the Hyundai Theta engine defect lawsuit

- Houston, TX, USA

Vehicle is putting out a very strong gasoline odor, especially when sitting idle. I looked up previous recalls on the vehicle and seen where there was a recall I believe in 2022 for similar issues.

- Jacksonville, AL, USA

My vehicle suffered a sudden engine failure that Hyundai confirmed was caused by a recall defect. Hyundai replaced the engine but is refusing to reimburse several necessary expenses incurred solely because of the recall-related failure. There was no warning lamps or messages prior to failure. Expenses: Monthly loan payment while car unusable -?" $242.55 (REFUSED) First tow: Highway -?' Old Ox -?" $160 (REFUSED) Second tow: Old Ox -?' Alexandria Hyundai -?" $170 Third tow: Alexandria Hyundai -?' Exxon -?" $200 Fourth tow: Exxon -?' Fitzgerald Hyundai -?" $205 Alexandria Hyundai inspection -?" $199.99 (REFUSED) Old Ox diagnostic fee -?" $539.24 (REFUSED) Rental car 10/4-?"10/8 -?" $208.90 Rental car 10/29-?"11/1 -?" $151 Total requested: $2,076.68 Total refused: $1,141.78 Hyundai claims the initial tow isn-??t covered because it wasn-??t to a Hyundai dealer, that independent diagnostics -??don-??t qualify, -?? that a Hyundai dealer-??s inspection fee is not reimbursable because dealers are -??separate entities, -?? and that my loan payment is not covered. These denials contradict Hyundai-??s recall guidance and the requirement to reimburse reasonable and necessary costs caused by a recalled defect. This engine failure also placed me in real danger. The engine died suddenly at highway speed, leaving me stranded in an unsafe location with no control over the tow provider. Hyundai Corporate then instructed me to bring the car to Alexandria Hyundai, creating the clear impression those fees would be reimbursed. I relied on their guidance in good faith, and only after following their instructions did they refuse reimbursement. I feel misled, financially harmed, and exposed to unnecessary risk. Due to Hyundai-??s conduct and selective denial of valid recall-related expenses, I am preparing to escalate this matter civilly and pursue punitive damages in addition to reimbursement. I request NHTSA-??s assistance, as Hyundai-??s actions appear inconsistent with recall obligations. Thanks, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMAT

- Mclean, VA, USA

Engine failed on 10/24/2025. Hyundai will not honor class action suit to repair engine at no cost to owner. Hyundai state recalls were not completed on the car prior to engine failure. We agree, recalls were not completed prior to failure. Because we never received notification. Had we received notification we would have acted on the recalls immediately and not put our safety, that of our children or the general public at risk by driving a vehicle with an engine that could fail at any moment. We have contested Hyundai's rejection several times to no avail. We are seeking guidance in resolving this mater.

- Springfield, VA, USA

My 2015 Hyundai Sonata has a defective engine. The motor failed unexpectedly even though the car has low usage and has always been maintained properly. I was informed that many Hyundai engines from these years came with manufacturing issues, and mine appears to be one of them. I am requesting that Hyundai replace the engine or provide a proper solution since this defect is not due to misuse but a faulty motor that came from the manufacturer. I need this resolved as soon as possible because the car is not running at all.

- Coral Spring , FL, USA

While I was driving at approximately 55mph, a loud clank happened and the car stalled, and smoke started pouring out of the hood and through the vents into the cabin, and I was leaving burning pieces behind on the road. I pulled over, ran to the back to get my dogs out of their crash tested kennels in the backseat, and both rear doors & passenger front door were locked. I ran up front to unlock them, and the unlock button did not work. I tried the unlock on the keys and it did not work. Due to having a recommended crash safe kennel set up it was not possible to crawl into the back to open it from the inside. My dogs were trapped in a car that was filled with smoke and on fire for over 2 minutes while I debated breaking the windows. I managed to fish a wire into the back to unlock and pull the door open from the inside of the back doors. The car stopped burning but was still smoking for several minutes after & I was able to clear the smoke to make it safe for my dogs to wait for a tow. When the mechanic looked at it he said the engine blew up due to the rod shattering into the block, destroying the entire engine and spilling oil which lit on fire. Mechanic recommended I contact Hyundai for engine replacement as this was a known issue with other 2015 Hyundai sonatas which were recalled due to risk of a defect rod knock causing the rod to shatter causing high speed stalling. Hyundai says my engine was not included in that specific recall. I included photo of the shattered rod which fell out when the mechanic lifted the vehicle

- Cisco, IL, USA

I heard noises immediately after purchasing the Sonata. I took it back in to Carmax ( where I bought it from) multiple times and was told they didnt find anything wrong. As time went on, I took my sonata to Hyundai dealer to get checked out. 1st time they told me, Hyundai wouldnt cover the cost to check out engine & that it would be $700 to take a look. The 2nd time, I was told we cannot check it out because the engine light isnt on. Basically they couldnt scan/check codes without the light being on. I suggested that if they just rode around the block, that they would notice that there's an issue. They still said no. Then back in February, I took back to Hyundai dealer again & they did check it out because the engine light was now on. That inspection came back as the cylinder was bad. Hyundai doesnt cover it because at that point it was past 100k miles and I was not the original owner. I asked about 100 mile.warranty when I bought it at carmax and was told yes 100k warranty still applies. So upon further research, hyundai has had problems with this year/make/model/ engine type before. If they knew something was wrong with it, why not just say so & fix it" Or as soon as I seen the first issue, check it out and repair it for me"

- Joliet , IL, USA

On the highway, my 2015 Hyundai Sonata suddenly began making a squealing or metallic rattling noise. At first, I thought it might have been something loose inside the vehicle. Within moments, the check engine light began blinking, followed by several additional warning lights and a pronounced knocking noise from the engine area. Immediately after the warning lights appeared, the vehicle entered a reduced-power -??limp mode-?? and began rapidly losing speed, even though the engine was still running. Because this occurred at highway speed while surrounding traffic was traveling normally, I had to pull onto the shoulder to avoid being struck. This created a significant safety hazard. I was stranded for approximately 45 minutes on the shoulder, at risk of being struck by other vehicles passing at high speeds. A tow truck arrived before the highway patrol, and the vehicle was towed home. When I returned home, my code reader pulled two versions of diagnostic code P1326, which is associated with potential engine bearing failure in Hyundai Theta II engines. The issue has since been inspected by the dealership, who confirmed the presence of the P1326 code. The vehicle is currently available for further inspection upon request. There were no prior symptoms that I was aware of leading up to the incident other than the brief squealing/rattling noise and the sudden warning lights immediately beforehand. The failure happened suddenly and without warning, causing an immediate and unexpected loss of speed and creating a dangerous situation on the highway.

- Deltona, FL, USA

1. Description of Safety Problem: My vehicle experienced a sudden catastrophic engine failure while driving, resulting in a complete loss of power and severe engine knocking. This is a known safety defect related to the Theta II engine (specifically, connecting rod bearing failure, often referred to as the KSDS defect) that poses a severe risk of stalling and engine fire. The failure rendered the vehicle inoperable and unsafe. 2. Manufacturer's Failure to Honor Safety Recalls & Warranty: Despite this being a known, documented defect covered by Hyundai's own Technical Service Bulletin (22-EM-00H-1-1) and the TXXI Class Action Settlement-?"which provides a "Limited Lifetime Warranty" for this issue-?"Hyundai Motor America has repeatedly and wrongfully denied my warranty claim. Furthermore, I discovered through Hyundai's official campaign portal that my specific VIN had multiple unperformed safety and service campaigns, including critical Engine Control Module (ECM) updates (Campaign #953) designed to monitor and prevent this exact type of engine failure. Hyundai's failure to ensure these critical updates were performed constitutes negligence and directly contributed to the safety failure I experienced. 3. Evidence of Manufacturer Bad Faith: I have obtained documented proof that Hyundai has approved and performed zero-cost engine replacements for the identical defect on vehicles with mileage exceeding 180,000 miles. This proves that my denial is arbitrary, discriminatory, and demonstrates a pattern of bad faith in applying their safety-related warranty extensions. 4. Escalating Consequences: Due to Hyundai's refusal to honor its warranty, the dealership has now threatened a mechanic's lien and is charging $50 per day in storage fees. The manufacturer's failure to address a known safety defect is now causing active financial harm. 5. Requested Action: I urge the NHTSA to: Investigate Hyundai Motor America's systemic failure to honor the safety warranties and complete

- Wilmington, DE, USA

The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at 40 MPH, there was an abnormal sound coming from the engine before the vehicle stalled. The contact pulled over to the side of the road. The check engine warning light was illuminated. A dealer was contacted. The vehicle was taken to the dealer, where it was diagnosed and determined that the knock sensor had failed, and that the engine needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure and offered a buyback. The approximate failure mileage was 155,000.

- San Diego, CA, USA

The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at 40 MPH, there was an abnormal sound coming from the engine before the vehicle stalled. The contact was able to pull over to the side of the road. The check engine warning light was illuminated. A dealer was contacted. The vehicle was taken to the dealer, where it was diagnosed and determined that the knock sensor had failed, and the engine needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure and offered to buy back the vehicle. The approximate failure mileage was 155,000.

- San Diego, CA, USA

Knock sensor has gone bad

- Fort Walton Beach, FL, USA

Engine malfunction putting my safety at risk. This is a known issue under Hyundai-??s active campaign, and the issue was verified by the manufacturer. A PA was required and Hyundai is refusing to repair vehicle due to service records prior to my ownership not being available. This issue was identified on 9/4/2025.

- Warner Robins , GA, USA

I was driving (I4 highway) when my car suddenly stalled, causing engine failure and almost putting my life at risk, causing an accident. This car has a factory recall for engine damage. I took it to the dealer, and Hyundai refuses to accept the engine repair because the title is rebuilt. The car has no damage to its original engine and is ready to be replaced. They don-??t want to assume responsibility.

- Kissimmee, FL, USA

Engine Failure for a 2015 Hyundai Sonata SE 2.4L In-Line4 (144CI) VIN(F) Odometer 141477. Engine starts then runs hot starts clunking and sputtering and then shuts off. Burns oil and has caused a complete exhaust failure. Vehicle cannot past emissions text. The vehicle was a safety risk as the engine may catch fire and the vehicle was use for transportation to work and children to school. The Engine Light stays on constantly the engine oil light comes on as oil is burned off. Vehicle was purchased at a third party dealer and as the new owner did not receive recall notice or settlement notice.

- Cedar Hill, TX, USA

The engine light started to come on and go off. I had the spark plugs changed and I kept regular maintenance done on oil changes and tune ups. Now my engine is knocking and the vehicle is in limp mo. I took to dealership for extended warranty it was denied due to not properly maintained I turned an additional maintenance records the claim was never reevaluated I took my car home which is only 3 mi away in the engine caught on fire before I could get home $9,000 loss I don't know what to

- Jefferson City, MO, USA