2015 Hyundai Sonata Engine

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!!

The car is burning a quart of oil a week.

Engine locked up

My 2015 Hyundai Sonata experienced Service Campaign TX3, TSB# 15-01-022, with an error code of P0010. My car was in the repair shop from Thursday, February 19th, until Thursday, February 26th, being repaired. This cost me roughly $2,300.00 out of pocket. When I attempted to file for reimbursement through Hyundai, I was told they were not reimbursing me. My car experienced failure the first of February. When my mechanic investigated what had happened, it was in fact, due to the service campaign.

I JUST GOT THIS CAR ABOUT 2 MONTHS AGO AND NOW I AM BEING TOLD I NEED A NEW ENGINE. I JUST LOOKED UP 2015 HYUNDAI SONATAS AND SEE THAT THIS MODEL DOES HAVE REPEAT ISSUES OF ENGINE FAILURE SO I DO NOT UNDERSTAND WHY THIS VIN NUMBER IS NOT UNDER THE RECALL LIST SINCE I AM HAVING THE SAME ISSUE

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 could endanger other drivers.

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.

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.

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.

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.

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

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?

Hyundai is denying a lifetime warranty claim on my 2015 Hyundai Sonata. Recalls have been completed on my vehicle and even with knock sensor recall completed my engine light is not on and they will not grant me a new engine. If though the Hyundai Dealer agrees that the engine has the bearing issue that would grant me a new engine.

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.

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.

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.

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

The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle lost motive power. There was no warning light illuminated. The vehicle was towed to an independent mechanic where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 92,000.

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