Engine And Engine Cooling Problems of Hyundai Sonata - part 2

On 11/28/25 at approximately 6:30 pm, I was driving on a highway 17 going about 60 mph when my car's engine completely shut down. A "hybrid system failure" warning flashed and my car was no longer drivable. The car was towed to the dealership. In mid October 2025, my car stopped running with the same "hybrid system failure" warning, but it happened in my driveway. The car was towed to the dealership and supposedly repaired.

See all problems of the 2023 Hyundai Sonata 🔎.

While driving on the highway, my 2018 Hyundai Sonata experienced sudden loss of engine power and became undrivable. The failure occurred without warning at approximately 86,500 miles. At the time of the incident, there were two children in the vehicle, and the breakdown occurred at night in cold temperatures (approximately 20°f). An authorized Hyundai dealership later diagnosed zero compression in cylinder 3 and confirmed a cracked piston, recommending full engine replacement. The sudden loss of power while driving created a safety risk due to traffic conditions and environmental exposure.

See all problems of the 2018 Hyundai Sonata 🔎.

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.

See all problems of the 2015 Hyundai Sonata 🔎.

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.

Hyundai replaced my engine under warranty due to their oil consumption in mid October. About 2 weeks later all warning lights came on and they said need new battery. They put in new battery in November. 15 miles after new battery a burning smell and smoke came from under hood with visible smoke. Took to dealer following day and no smoke. Got car back and next day it’s smoking and burning smell. Got it back to dealership and they had it a while and said no smoke and I got car back. They can’t find a reason and it’s not smoking . About a week later (tonight) burning smell and smoke from under hood at the engine.

See all problems of the 2019 Hyundai Sonata 🔎.

I am filing a complaint regarding Hyundai motor America’s handling of my engine-related safety issue, buyback process, and rental reimbursement. My vehicle was towed to elder Hyundai for a suspected engine failure. Elder Hyundai informed me that my car was covered under an engine recall campaign and that they would submit a request for free repair. Shortly afterward, Hyundai motor America notified me that they would not perform the repair and that I was being forced into the buyback process under a settlement agreement release (sar). Elder Hyundai refused to provide me a loaner vehicle because I was not proceeding with repairs, despite the issue being part of an engine recall. They also refused to give me the repair order report for my records and refused to let me retrieve my personal items from my vehicle unless I paid a diagnostic fee. Hyundai motor America told me I was covered under them for this fee, yet elder Hyundai still refused. Regarding transportation, I was initially told Hyundai does not reimburse turo rentals due to concerns about “fake receipts. ” because of my budget and age, turo was the only rental option I could afford. After escalating, a supervisor approved reimbursement for my turo rentals, but as of today I have not received any reimbursement. I am a school teacher with a two-hour commute each day and I have [xxx] twin toddlers. I had to use rent and bill money to pay for the rentals based on assurances that reimbursement would be processed within a week. I submitted all receipts, but my new case manager claims he has no record of them, further delaying reimbursement. I completed and returned all sar buyback documents on November 15th, yet I have received no update on payment or processing. This entire ordeal has put me at financial risk, including potential job loss and housing instability. Hyundai’s delays and mishandling of this safety-related case have severely impacted my livelihood. I ask that you please review hma’s action information redacted pursuant to the freedom of informa.

See all problems of the 2017 Hyundai Sonata 🔎.

The contact owns a 2006 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle experienced a loss of automotive power. No warning light was illuminated. The contact was able to pull over to the shoulder of the roadway and noticed that engine oil was leaking onto the ground and the coolant level was abnormally low. The contact stated that the vehicle failed to restart and was towed to a local independent mechanic, where it was diagnosed with a valve cover leak. The vehicle was repaired at the owner's expense; however, the failure reoccurred. The local dealer was not contacted. In addition, the contact stated that several other unknown repairs were made; however, the failure reoccurred. The contact related the failure to an unknown NHTSA campaign; however, the VIN was not included. The manufacturer was made aware of the failure. The failure mileage was approximately 112,000.

See all problems of the 2006 Hyundai Sonata 🔎.

My 2013 Hyundai Sonata qualifies for a lifetime warranty engine replacement under the theta ii class action settlement. The dealership is refusing coverage unless I provide maintenance records, even though the settlement prohibits denial based solely on missing records or the presence of sludge. Hyundai must prove neglect caused the failure, which has not been demonstrated. I am requesting review by the engine settlement team and approval of my engine replacement.

See all problems of the 2013 Hyundai Sonata 🔎.

The engine is burning oil around 1 quart every 700 miles. I check the car oil level around every 10 days. I have experienced when I didn't check the oil and the low oil engine light would come on in the instrument panel. Hyundai shows no recall for this 2019 Hyundai Sonata limited edition. I believe that this type of incident occurred back around 2011 with Hyundai's models for that time.

Car stalls and shuts down while shifting to park or reverse and when slowing to turn or stopping. Also the media screen will black out and not work at times.

I am reporting a safety-related engine failure involving my 2011 Hyundai Sonata 2. 0t. In November 2025, at approximately 90,000 miles, the vehicle experienced a sudden engine failure while driving, including loss of power and abnormal engine noise. This created an unsafe driving condition and required the vehicle to be removed from service. Component/system involved: the engine (theta ii 2. 0t) suffered a catastrophic internal failure. The engine and internal components remain available for inspection upon request. Safety risk: the sudden loss of engine power reduced my ability to maintain speed and maneuver in traffic, posing a safety risk to myself and other motorists. Confirmation and inspection: the failure was confirmed by an authorized Hyundai dealership, which inspected the vehicle and documented the internal valve train condition through photographs. Hyundai motor America reviewed the claim and issued a written denial. No independent third-party technical inspection was performed. Prior symptoms: before the failure, the vehicle had a history of excessive oil consumption requiring frequent monitoring and oil addition despite regular maintenance. Abnormal engine noise was present for approximately one minute before failure. No warning lights adequately predicted the sudden failure. Additional context: this vehicle is equipped with a theta ii engine, which has been the subject of prior recalls and settlements related to internal engine defects. Hyundai denied warranty coverage alleging “exceptional maintenance neglect”; however, inspection photos show a well maintained valve train with no sludge or oil flow obstruction, only light surface varnish consistent with normal engine aging. I am concerned this failure represents a continuation of a known theta ii engine defect (confirmed by Hyundai technician who performed inspection with obd code p1326 followed by engine failure) and poses a serious safety risk due to sudden loss of engine power while driving.

See all problems of the 2011 Hyundai Sonata 🔎.

See attached document for complaint.

On November 10, 2025, my 2016 Hyundai Sonata hybrid (VIN [xxx] , approximately 150,000 miles) experienced a sudden loss of power while I was turning right and accelerating into traffic. The vehicle immediately entered limp mode with flashing warning lights and audible alerts. The vehicle lost normal propulsion and could not accelerate properly, creating a dangerous situation as it was blocking a traffic lane. I was forced to limp the vehicle into a nearby parking lot to get out of traffic. The vehicle was not safely drivable afterward and was towed home. A few days later, the vehicle was towed to murdoch Hyundai in lindon, utah, for diagnosis. The vehicle was found to have diagnostic trouble code p1326, which Hyundai identifies as activation of the knock sensor detection system (ksds) related to connecting-rod bearing wear. This condition is part of Hyundai’s known engine defect and safety recall/warranty extension programs. During inspection, the dealer observed that the valvetrain did not show signs of neglect or sludge, which is inconsistent with oil starvation or severe maintenance neglect. This further supports that the failure is consistent with the known connecting-rod bearing defect addressed by Hyundai’s ksds safety recall, rather than a maintenance-related issue. This is a safety issue because sudden loss of propulsion or reduced power while entering traffic creates a high risk of collision. Hyundai customer care has been unwilling to open a new case number or escalate review, and the dealer has indicated possible denial of engine replacement coverage based on incomplete oil-change records, despite the vehicle exhibiting the ksds safety condition. I am requesting NHTSA review of this safety-related defect and the manufacturer’s handling of ksds/p1326 failures. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2016 Hyundai Sonata 🔎.

My 2018 Hyundai Sonata’s oil light flashed briefly while driving, so I checked the oil level and found the dipstick completely dry. The car has been maintained regularly and was still about 1,000 miles away from its next scheduled oil change. There are no visible leaks, and the engine is not smoking. I had to immediately add oil to prevent engine damage. This appears to be a case of excessive oil consumption, which I have since learned is common in Hyundai Sonatas with this engine. I am very concerned that low oil pressure could cause engine failure or sudden loss of power while driving, creating a serious safety hazard. I request that NHTSA investigate this issue for 2018 Sonatas, as many owners are reporting similar experiences, and Hyundai has issued a technical service bulletin (TSB 23-em-008h) about excessive oil consumption but no recall.

Car started misfiring while driving and engine light came on. It kept losing power but I was able to pull off highway. This put myself and others in danger because speed was significantly reduced suddenly. Dealer said problem was due to oil leaking on spark plugs. The car had been using excessive oil. Dealer said this is known issue but I had to pay for any repairs since I was the second owner. Hyundai still pays for the original owner to get an oil consumption cleaning, but recently stopped paying for secondary owners. If the oil consumption cleaning does not work, then the next step is to replace engine, paid by customer if Hyundai refuses. Mileage on car is 75,769.

New battery keeps dying, car not starting and when it does start it shuts off when I brake. Oil light on after I already put oil in the car.

My 2016 Hyundai Sonata with the dohc gdi theta-ii engine is experiencing severe engine oil consumption consistent with Hyundai's known txxi/txxc extended warranty defect. The oil pressure warning has flashed while driving or braking, the engine runs rough when slowing down, engine has made knocking noises, and there is smoke/vapor with a burnt oil smell when removing the oil cap after driving. The oil level drops rapidly between changes despite proper maintenance. This issue poses a risk of engine failure, stalling, or fire while driving. I have maintained the vehicle on time with all oil change receipts. A Hyundai dealership refused to perform the required warranty diagnostics even though this issue falls under Hyundai's extended warranty for theta-ii engines. This is a serious safety concern, and no corrective action has been taken.

The vehicle is going through oil very quicky. No leaks no burning.

The vehicle experienced a sudden engine failure and loss of power while traveling at freeway speed. Two days earlier, the vehicle had been taken to an authorized dealership for factory recall service. During that visit, concerns were raised about known engine issues associated with this model, but the vehicle was returned to service. While driving on the freeway, the engine abruptly stalled without warning, causing immediate loss of propulsion and power. This created a dangerous situation in moving traffic, requiring rapid maneuvering to avoid a collision and safely exit traffic lanes. The vehicle became inoperable and could not be restarted. The failed component appears to be the engine or related internal engine system. The vehicle was towed back to the dealership following the incident and has remained inoperable since that time. The vehicle is currently available for inspection. The failure placed the driver at significant risk due to the sudden loss of power at highway speed. No collision occurred, but the risk of serious injury or death was present. The problem has not been reproduced because the vehicle has remained disabled since the incident. The dealership and manufacturer have inspected the vehicle after the failure. The manufacturer is reviewing the incident under an internal process. There were no prior warning lights, messages, or symptoms indicating imminent engine failure before the stall. The failure occurred suddenly and without advance notice.

See all problems of the 2014 Hyundai Sonata 🔎.

The vehicle experienced an engine and power train failure while driving on the highway, resulting in sudden loss of power. The electrical system also failed after the dealer visit, causing the battery to die every morning. Yes, the vehicle is available for inspection upon request. My car suddenly lost power on the highway and would not accelerate, forcing me to pull over on the shoulder with traffic moving around me. This created a serious risk of a rear-end collision or crash. Additionally, after the dealer visit, the electrical system began failing and the vehicle has been completely dead every morning, leaving me stranded with a child and unable to reliably start the car. The problem has not been reproduced because the check engine code cleared itself after the incident; however, the symptoms absolutely remain. The dealer refused to diagnose the loss-of-power event because the code was cleared, and they returned the vehicle to me with a dead battery. The electrical issue (car dying every morning) has been happening consistently since the dealer visit. The vehicle was taken to a Hyundai dealership immediately after the incident, but they refused to diagnose the loss of power due to the code being cleared. A mobile mechanic scanned the code at my home before the tow, but the code disappeared afterward. The electrical failure began after the dealer visit and has not been properly inspected by Hyundai. Yes. While driving on the highway, the check engine light came on and the car immediately lost power and would not accelerate. After the dealer visit, the car has been completely dead every morning and requires a jump to start. These symptoms began on the same day as the highway incident and continued after Hyundai serviced the vehicle.

This vehicle has experienced multiple hybrid system failures while driving, including a complete loss of power “hybrid system warning – turn engine off” on the interstate in June 2022 through November 2025. These events have placed me and my loved ones in dangerous driving situations. Despite a warranty?covered engine replacement at 82,015 miles (January 2023), the same hybrid system issues have recurred. Hyundai initially indicated a warranty claim was submitted, then told me there was no record of any claim in the system. The dealership claims it was denied — creating a serious inconsistency in communication and accountability. In addition, I have identified multiple NHTSA complaints in the database from other owners of 2016 Sonata hybrids (vins beginning with kmhe) describing similar highway shutdowns and hybrid system failures, which raise concern about a broader, unaddressed safety defect not currently covered by existing TSB or recall actions. I am respectfully requesting: a regional inspection and review of my vehicle prior to any further work. A review of Hyundai’s handling of this warranty claim and the discrepancy between dealer and corporate communication. Assessment of whether the hybrid system failures in kmhe?prefix Sonata hybrids warrant further safety action.

While driving my 2017 Hyundai Sonata, the engine suddenly began making a loud knocking noise and the vehicle entered "limp mode" the check engine light was blinking, I took the car to a very close autozone and the check engine light came on with code p1326 (pricture upload files), which is directly related to the known ksds connecting rod bearing defect. This issue is part of Hyundai’s safety recalls and engine warranty extensions. After that, I called Hyundai directly (reference number for that call #xxx). A kind young woman informed me that my car had been through "service campaign 953" and successfully completed a "knock sensor detection system (ksds) software update. " thanks to this, she explained that my car is under the "Hyundai txxi warranty" and that, given the noise I was hearing along with the "p1326" code, it was very likely that my car qualified for a free engine replacement. She then scheduled an appointment for me at the nearest Hyundai dealership for the following morning. After more than two weeks of inspection, the dealer confirmed that the engine has internal damage and needs a complete replacement due to rod bearing failure. This is the exact defect addressed in Hyundai’s safety campaigns. However, Hyundai corporate is refusing to cover the engine replacement because the vehicle exceeded its mileage limit, even though the engine failure is clearly caused by the known safety-related defect. The dealer acknowledged the problem and documented everything, but Hyundai is denying proper safety recall-related coverage. This puts my safety and the safety of others at risk, the vehicle is currently disabled and undrivable at the dealership due to the defect. Hyundai is only offering a buyback or a small cash settlement instead of performing the necessary safety repair. I am filing this complaint for many reasons but mainly because the refusal to replace the defective engine, despite the recall-related code p1326 and confirmed bearing failure. Information redacted pursuant to the freedom of infor.

I am the original owner of a 2017 Hyundai Sonata with the oil consumption defect Hyundai is well aware of. For years I have been adding a quart of oil every thousand miles and had my spark plugs replaced three times in two years now. Why am I not included in the recall so I can have the repairs done free of charge? the dealer wanted me to start having them monitor my oil consumption first which will cost me around seven hundred dollars for something they already know is defective. I submitted repair bills for the spark plugs to Hyundai around a year ago, but they would not reimburse. This is a safety issue as car starts to run badly with fouled plugs.

Engine issue - but no recalls there have been hundreds of this same car yr and model with engine issues out of the blue.

My engine recently seized on my vehicle and Hyundai is refusing to replace my engine. Per their website my vehicles engine has a lifetime warranty. This warranty is eligible for class vehicles who have has to campaign 953 reformed on their vehicles prior to engine failure. This was performed in n my vehicle on April 16, 2019. Per Hyundai’s website. I am being offered a settlement I did not take part in instead of my engine replacement and it should be illegal for them to go against their own word.

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at an undisclosed speed and making a left turn, the vehicle experienced a loss of motive power. The contact was able to restart the vehicle; however, an abnormal knocking sound was heard, and there was smoke coming from under the hood. The contact was able to drive the vehicle to a nearby residence, where it temporarily remained. The contact attempted to drive the vehicle a few miles to qualify for towing, per the vehicle insurance provider. The vehicle was towed to a local dealer, where it was diagnosed with a rod bearing failure. The vehicle was not repaired due to insufficient engine oil maintenance records. The contact related the failure to NHTSA campaign number: 20v746000 (engine). The manufacturer was made aware of the failure. The failure mileage was approximately 137,600.

The vehicle experiences a recurring defect where the brake light turns on suddenly and the engine shuts off while driving. The failure appears related to the braking system (brake switch circuit), electrical system (can-bus/ecu communication), and engine control (shutdown/stall). The system remains installed and is available for inspection upon request. The shutdown poses a serious safety risk, including possible rear-end collision or loss of power in traffic. The problem has occurred multiple times. The dealership inspected the vehicle briefly but failed to diagnose or document the defect and returned the vehicle within hours, stating “it shouldn’t be a problem,” even though the issue continues. Hyundai has refused to provide recall documentation or authorize a re-inspection. The only warnings prior to shutoff are the sudden activation of the brake warning light just before the engine cuts off.

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.

While driving, my 2016 Hyundai Sonata’s engine suddenly started knocking loudly. I stopped immediately and found the engine oil was very low without any prior warning. After adding oil, the engine still runs but with possible internal damage. This could have caused the engine to seize while driving. There were no warning lights or leaks before this happened.

The contact owns a 2011 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the engine started to overheat, with the check engine and temperature warning lights illuminated. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 184,000.

The contact's daughter owns a 2013 Hyundai Sonata. The contact stated that the vehicle failed to start. The contact's daughter replaced the battery. A mechanic was able to restart the vehicle; however, the engine made an abnormal knocking sound. The vehicle was not diagnosed or repaired. The contact related the failure to NHTSA campaign number: 17v226000 (engine and engine cooling) for which the VIN was included. The dealer and the manufacturer were not contacted. The failure mileage was approximately 95,000.

I have just purchased this vehicle from jones Nissan in savannah, TN September 27, 2025 for my daughter's 18th birthday. I was told the car passed all inspections etc and was sold the car same day. We checked the oil before leaving and oil was good. Within 45 miles we came home and my husband checked the car and the oil was down half quart. We didn't think anything of it and he did complete oil change. Last night my daughter comes in and my husband checks her oil almost 3 quarts low. There are no leaks nothing we can find. This is absolutely absurd this was a car for my 18-yr old daughter to go to college and back. There are no lights that come on to tell you it is low or nothing. This is completely uncalled for and Hyundai needs to replace or correct this issue. This could cause her to be stranded or hurt if this motor was to lock up.

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.

I bought this car from someone in April of 2024 and the person who I bought it from said everything was perfectly fine, they brought it to the Hyundai dealership and according to the mechanic there the engine was fine…. I have taken care of the engine since I bought the car, kept up with oil changes and everything…. Until a few days ago when the whole thing ceased up on me while driving down the road to my sons school. I wasnt going fast either, the speed limit is 40mph where I was when it happened, but I’m glad I have quick reflexes because otherwise we would have wrecked the car. Everything shut off on me and now its knocking. There is alot of metal shavings in my oil and my mechanic tried to drain it a few times to get the debris out of the oil but it does no good.