2015 HYUNDAI SONATA Engine Problems

Engine has knocking sound. Sudden loss of power and hesitation when accelerating

The vehicle suddenly lost power while driving on a public roadway. Immediately after, the vehicle began producing a large amount of smoke. The smoke quickly filled the cabin, making it difficult to breathe and creating an urgent safety hazard. My passenger and I had to exit the vehicle right away due to the amount of smoke. We were exposed to smoke inhalation and were stranded on the side of the road in unsafe weather conditions for over an hour while waiting for a tow truck. I later learned that the vehicle had an open recall related to engine issues; however, I was never notified of this recall. Regardless of recall status, the sudden loss of power combined with heavy smoke and potential fire risk created a dangerous situation that could have resulted in serious injury or death. I believe this issue represents a serious safety defect and fire hazard that...

Component/System Failed: Engine – connecting rod bearing failure consistent with Hyundai Theta II engine defect subject to federal recalls and Consent Orders. The vehicle previously received Recall Campaign 953 (KSDS software update), intended to detect premature rod bearing wear. The engine is currently knocking and has been diagnosed as requiring replacement. The vehicle and engine are available for inspection upon request. Safety Risk: Rod bearing failure can cause sudden engine seizure or stall while driving, creating a significant crash risk due to loss of power steering and braking assist. Engine failure DID occurr despite prior recall software update, indicating potential recall remedy ineffectiveness. Sudden stalling in traffic placed myself and others at risk of collision. Dealer Confirmation: Hyundai of North Charleston confirmed through warranty history a prior engine replacement request (PA) was submitted by a previous owner but denied. The recall repair was never performed. Current diagnostic findings indicate engine...

While driving on the freeway, my vehicle experienced a sudden and catastrophic engine failure. The check engine light began flashing, the vehicle lost power, and I almost lost control of the car. I barely had time to pull over to the shoulder to avoid an accident. The vehicle was towed to a Hyundai dealership. The engine does not start and the engine block is cracked. Hyundai denied coverage stating that a software update (Campaign 953) was not installed. Campaign 953 is only a detection update and does not repair or prevent internal engine failure. This is a serious safety issue.

Was driving car and it went completely hot. Towed to a dealership and they said was not drivable and that the radiator support and radiator hose needs replacing and eventually the Drive CV left and front will need replacing or I will be stranded on side of road.

I have been dealing with issues with the turbo that cost over $3k out of pocket to get "fixed" only to have a part go bad and needed to be replaced. Now the engine is bad and needs to be replaced. The dealership is horrible at being honest and treat me as if that's not my only vehicle. I ask for a loaner car and thery never respond!!

Engine locked up

The car is burning a quart of oil a week.

On January 21, 2026, while driving on I-495 at highway speeds (e.g. 50-60 mph) in heavy traffic, my car made a "clunk" sound and I suddently was unable to accelerate. There were no warning lamps, messages, or other symptoms prior to the failure, but immediately when it happened several warning indicators, including the check engine light, oil light, and tire pressure indicator, lit up. The electrical systems and brakes appeared to still work, but the best I could to was coast onto the nearest shoulder and call for an emergency tow. I waited on the shoulder of a busy highway, in the dark, for over an hour. My car apparently has a type of engine that is known for catastrophic failure, so I assume that is what happened. I had the car towed to a Hyundai dealership and they confirmed that the engine needs to be fully replaced.

The oil in the car burns quickly. After driving 2000 miles, there is no oil left. I do not have any oil leaks anywhere. It’s just burning oil. This has been consistent since I’ve gotten the vehicle.

While driving my 2015 Hyundai Sonata, the vehicle suddenly lost power and entered limp mode. A loud engine knocking noise was present, and acceleration was severely limited, creating a safety risk in traffic. The check engine light illuminated at the time of the failure. An independent mechanic confirmed diagnostic trouble code P1326, related to the engine knock sensor detection system designed to detect early engine bearing failure. The condition occurred without warning. The vehicle is currently not being driven to prevent further damage and is available for inspection upon request. Sudden loss of power while driving poses a serious safety hazard. This appears to be a known engine defect affecting similar vehicles.

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

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...

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.

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...

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.

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

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 – $160.00 (REFUSED) Second tow: Old Ox → Alexandria Hyundai – $170.00 Third tow: Alexandria Hyundai → Exxon – $200.00 Fourth tow: Exxon → Fitzgerald Hyundai – $205.00 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 – $151.00 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...

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.

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.

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...

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...

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...

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...

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.

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.

Knock sensor has gone bad

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.

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.

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.

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 do

Vehicle lost power leaving me stranded. All lights on dash came on, lost power, and barely able to steer to get off the road. We had to have it towed. The vehicle was towed to our mechanic, who states the motor seized up. Mechanic states there is no repair for this issue. Car has just been paid off. Now we have nothing!

The engine light started to come on and go off and when I got the codes ran, it said something along the line of misfire. 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 mode.

I started taking my car to the dealer in 2023 for engine problems, including high oil consumption and stalling. The dealer kept telling me to return in 1,000 miles instead of fixing it. The issue was officially documented again in March 2024 (RO #131797) with ‘Cause: high oil consumption.’ Despite paying \$356.46 for repairs, the problem was never resolved and now the engine has failed

Dear NHTSA Investigations Team, We are the owners of a 2015 Hyundai Sonata, purchased in 2016 and still in use today. This vehicle is suffering from severe engine issues linked to the Theta II engine defect, which has been the subject of recalls and class action lawsuits. For nearly a year, we have been forced to add approximately 2 quarts of oil every week due to extreme oil consumption. This is unsustainable, unsafe, and clearly linked to the known recall defect. The most serious incident occurred when my wife was driving on [XXX] in North Carolina, and the vehicle suddenly lost power. It could not maintain safe highway speed and had to be pulled off the interstate, requiring a tow more than an hour back to our home. This was a frightening event that could easily have caused a crash. We later discovered that our vehicle was included in the...

The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The contact stated that the vehicle failed to accelerate above 10 MPH. The vehicle was driven to the shoulder of the road. In addition, the check engine warning light was illuminated. The vehicle was towed to the dealer, where it was diagnosed with a failed knock sensor. The contact was informed that the engine needed to be cleaned. The vehicle was not repaired. The contact referenced an unknown extended warranty for the knock sensor; however, the contact was informed that the repair was not covered under warranty or recall. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 103,500.

P1326

I had a standard oil change done on my car and it was running fine afterwards. Later that evening, my car started smoking and spontaneously burst into flames from the hood. The fire originated in the hood of the car and melted the entire front of my car as well as the entire inside. It burned a lot of fuel and oil, which leaked onto the ground and continued burning on the ground. My car was overtaken by flames in a matter of a few minutes. It burned so fast that there was nothing I could do to stop it. I was not aware of anything wrong with my engine or fuel lines, or anything like that. However, something was very wrong for the engine area to catch fire like that spontaneously.

I have contacted the guy that sold me the car he Refused to fix the recall which is my motor I need Something done , Hyundai won’t Honor their Recall .

My car 2015 (Hyundai Sonata)started leaking oil, it only had 50,000 miles. my mechanic said the motor had too much pressure and kept pushing oil out. He advised me to take it to the dealership for a motor recall. The dealership gave it back with a list of things to fix. replaced the valve cover gasket but still leaked oil. I found out these cars have an oil leak problems that are not being addressed. My car went up in flames 2 weeks later. I have done everything I could to save this car but nothing saved it. My grandkids were in the car and it had traumatized them.

I bought this sonata one month ago. Driving down [XXX] in bonita springs Fla the car shut down. No noise all dash lights came on I got to a safe place. Sat in the parking lot of fresh market for at least 30 minutes went to start it and nothing happened. No crank nothing. AAA came towed it to my house. The filling day I checked the battery it is good. So had it towed to Scotty’s automotive. They called me Friday morning and said the motor was locked up. According to Carfax the car was at brand ton Hyundai in May of 25. I called after I bought the car Carfax said they found the alignment was off. I called to see if they did the alignment they said they did not do it. The wholesale it. My thinking is they did service it according to Carfax report and...

We were informed by our mechanic that the engine needed replacement due to a timing chain issue. The engine warning light was blinking continuously, and the RPM would not rise above 1.9 even under acceleration. Upon further inspection, the mechanic found that the issue extended beyond the timing chain - the entire engine appeared to be failing. When we changed the engine oil, it became dirty almost immediately, and visible metal shavings were present in the oil, indicating internal damage. These symptoms suggest potential engine failure, which is consistent with known issues in some Hyundai Sonata models. We believe this may be related to broader engine defects and request that this be investigated for potential recall eligibility.

Using 5 quarts of oil in 3 days.

The car was on a major highway, went to pass another car and the engine stopped working. While trying to get the car off the road there was almost an accident involving on coming traffic.

The turning signal gives the opposite signals sometimes.

The car burns oil. I have to put oil in it every few weeks. Also will start shaking while acceleration. I replaced engine coils several times. Main issue is burning oil, don't know why.

Our 2015 Sonata has experiencing Engine failure several times due to excessive and irregular oil consumption. Our family’s safety and the safety of others on the roadway were put at risk as the engine slows, shudders and stalls without prior warning and the check engine light does not come on until the vehicle slows and stalls. The vehicle was inspected at a local Hyundai dealership, and they indicated that this is not covered under warranty. Summary of Engine Issues and Failures: 1.May 3, 2022 – 68,671 miles (local Hyundai dealer) Check engine light on, shudder; oil change performed. No cause identified. Paid out-of-pocket. 2.August 23, 2022 – 75,527 miles (retail shop) Car engines failed on highway, towed to service shop. Valve cover gaskets replaced. Paid out-of-pocket in part and extended warranty paid part of the invoice. 3.April 29, 2024 – 109,229 miles (local Hyundai dealer) Excessive oil consumption noted; valve...

The car has had an electrical issue ever since taking to to get a recall around may of 2023. It will randomly brake and shift the transmission badly while downshifting. I feel as if my make and model falls under the theta II campaign they had to replace certain engines for having a knocking rod be fault and release shaving into the engine causing it to misfire. Not only that but the electrical issue is completely random it happens atleast once or twice a week. It had began ever since I took it for a recall, and when I took it back they found no issue and left food in the back of my car and the chairs leaned back. This was the Fontana Hyundai dealership

Multifunction box is in the steering column that controls your lights, signals, I put my turn signal on right or left at night and my lights go out,but they come back on.also I have zero warning lights on my dashboard for when something happens it let's you know,well I have none. Hyundai of California says it's not unsafe.it should be a recall because it's a thousand dollars for update..

I've been in communication with Hyundai Henderson, Nevada and Hyundai Corporate as result of engine problems with my 2015 Hyundai Sonata. Corporate instructed Hyundai Henderson to submit a "Goodwill Warranty Repair order. However Hyundai Henderson, who has already determined that the vehicle has total engine failure, is requiring that I complete the thousand mile oil consumption test. My car has already proven to be unable to drive a couple hundred miles before losing acceleration. This is a huge safety issue to ask a consumer to drive this vehicle or to put this vehicle on the road as it is. Please advise on how I may move forward with Hyundai Henderson and Hyundai Corporate. * I have my entire battery/oil/repair/tire history - will scan and submit if needed/ upon request - unable to attach here. Sincerely, [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C....