474 problems related to engine and engine cooling have been reported for the 2015 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2015 Hyundai Sonata based on all problems reported for the 2015 Sonata.
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 $2,300. 00 out of pocket. When I attempted to file for reimbursement through Hyundai, I was told they were not reimbursing me. My car experienced failure the first of February. When my mechanic investigated what had happened, it was in fact, due to the service campaign.
?I will take ?10k$ for the car or a new engine and steering, damages fixed. . I also need a rental by April 10th and $300 for inconvenience thus far. ?the engine ?stalled ?twice? when driving over 2 months! the lawyer won't be forgiving.
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!!.
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 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 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.
Engine – connecting rod bearing failure. Theta ii engine. Hyundai confirmed the defect via bearing clearance test (bct) on October 3, 2025. The engine can seize without warning, causing sudden loss of power while driving – a clear safety risk. The problem has been confirmed by an authorized Hyundai dealership (hertrich Hyundai of new castle). The manufacturer issued technical service bulletin 22?em?001h (txxi lifetime warranty) covering this exact defect. Despite confirming the failure, the manufacturer has refused to repair the engine. The vehicle is available for inspection upon request. No crash, fire, or injury occurred. Warning signs included engine noise and illumination of check engine light before failure.
Knock sensor has gone bad.
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 seized driving down the interstate doing 65 mph in rush hour traffic could have been rear ended or hit vehicles around me trying to get off the road. Complete loss of power. Power steering was still active brakes were barely working. No warning lights (I had the knock sensor recall performed). Engine simply locked up solid. I was able to safely make it to the disabled vehicle lane and put the car in park. Engine had no sludge buildup and looked excellent once it was disassembled by the dealer. All engine bearings had spun. Engine was completely replaced under the extended warrenty.
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 investigate Hyundai motor America's systemic failure to honor the safety warranties and complete.
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!.
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.
Engine locked up.
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.
P1326.
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.
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.
In August 2025, my car went into "limp mode" (go no faster than 40 mph and it was lurching and speed dropping) on the freeway, which was scary and dangerous. Once home, I called a certified mechanic. When this mechanic tried to start the car, it made a terrible clacking noise. He told me it sounded like the main bearings were going out. He discovered that there was a recall on this particular vehicle because the main bearings would fail. The local dealer confirmed that the car was subject to the recall and requested that the car be brought in. Because I am on limited income, I could not afford to have the car towed until November 2025. Once there, the dealership verified that the main bearings went out. A claim was made to the manufacturer. The claim was denied claiming "outside influence. " I provided service records to the manufacturer, but before they had all the maintenance records, they closed my case and will no longer take documents or even speak to me or the dealer. I have been without a car for almost 10 months. I have seen documented cases that trying to start the car could lead to dangerous engine fires.
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 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 knew there was signs something and wholesale it. I did not buy it from brandon Hyundai I bought it from a guy in leigh acres fla. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
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.
Using 5 quarts of oil in 3 days.
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 .