Engine And Engine Cooling Problems of Hyundai Sonata - part 2

Bought car from a used car dealership, car fax report filed 3 other owners, with a well maintenance report on file with oil change done atleast every 5k miles. Bought car in January 2026, maintenance had been done before car was taken off the lot. At 3k miles since hsving the CA on 05/15/26 I got my oil changed and cabin filters replaced. It’s only been less than 1500 miles and car engine had reportedly seized.

See all problems of the 2013 Hyundai Sonata 🔎.

I test drove the vehicle at an auction, watched several other people test drive the vehicle. Before the auction I test drove it one more time and put my obd scan tool on it to make sure there were no hidden codes or problems. I won the bid,and picked up the vehicle. I drove it approximately 6 miles from the auction and the falshing engine light popped on. I immediately pulled over in heavy freeway traffic. Put my scan tool on it and found out the knock sensor had triggered. The vehicle was shaking and making a terrible racket. It was inoperable in the worst possible spot on highway 51 during rush hour traffic. I managed to slowing coast down the offramp and roll into a parking lot. I then called purdy Hyundai and spoke with a service advisor and provided the VIN#. He (vue kue) informed me that the vehicle qualified for the recall and warranty work based on exactly that issue. I had the vehicle towed to the purdy dealership on July 8th 2026. I was told today that it was unlikely that Hyundai would honor the recall because I did not have service records of a vehicle I had owned for 6 miles of driving. I filed a complaint with Hyundai corporate. Claim#43010067 and awaiting the reconciliation of this situation. Of which they appear to to be avoiding.

See all problems of the 2011 Hyundai Sonata 🔎.

The oil is low, went to get looked at by another mechanic besides dealer cause they want to hit you over the head with prices. Was told car burning oil. Took to dealer for oil consumption test. Had to pay for oil change. Came back a little before 1,000 miles and car failed. They charging me 900. 00 for next step because I can’t find all the oil changes. I just don’t get it, if this is a known issue with this model engine why do I have to pay.

See all problems of the 2019 Hyundai Sonata 🔎.

The vehicle suffered an internal connecting rod bearing failure, a known manufacturing defect affecting the theta ii gdi engine. The failure was explicitly diagnosed via the manufacturer - specific obd-ii fault code p1326 knock sensor detector system. This defect causes sudden engine stalling poses an immediate risk of catastrophic engine failure or fire while driving. Hyundai motor America has denied financial reimbursement for the required engine repair because the work was completed by an independent shop and third-party arbitration deadline (bbb auto line) communicated to me. The manufacturer is actively refusing to remedy an acknowledged safety defect.

Cylinder 3 misfire code and rough idle/driving car tries to stall out, engine is consuming a quart of oil every 500 miles and has 30psi compression in cylinder 3. Car only has 129k miles.

See all problems of the 2016 Hyundai Sonata 🔎.

Engine misfiring and low compression.

See all problems of the 2015 Hyundai Sonata 🔎.

When my father was driving, the vehicle stalled out with no prior odd activity. He pulled over to the side of the road and attempted to start the vehicle. He saw smoke, opened the hood, saw flames and cleared the area of the vehicle. Due to the large Hyundai/kia engine recall for his year of vehicle, the engine had been replaced 2-3 times and only ever been serviced by the dealership. We do not know if all recall repair work had been done, because there was also a fuel line recall which was "fixed" in 2020 and 2022.

The check engine lights blinking, it overheats and it shuts down.

See all problems of the 2014 Hyundai Sonata 🔎.

Engine / short block assembly / connecting rod bearing seizure. The engine suffered a sudden, catastrophic seizure while I was actively driving on a steep incline mountain road with a cliff on one side and forest on other. The vehicle experienced an immediate, total loss of motive power, forcing an emergency maneuver onto the shoulder in 5 seconds with no power steering or power brakes, creating an extreme collision hazard on a high-speed incline. The rod bearing melted due to a manufacture defect and could have also possible caught fire in heavy fire country. The fuel pump was also leaking recently and just replaced. They are nearly $1800 for a new pump because of price gauging because they are in "high demand". The check engine light was solid (not flashing) for a thermostat code (p0128) due to extreme internal friction/heat from the failing bearings. There were no flashing ksds warnings or physical signs of engine overheating. My car was denied a new engine under a federally mandated warranty explicitly stating the exact symptoms of internal engine defect that happened in my car under "owner neglect" even though I have changed my oil regularly and even before the manufacture recommended time frames to do so. I've changed the valve covers, 02 sensors, thermostats, and plenty more on this car than any other car I have ever owned proving I'm actually an exceptional owner. I remained nice to all corporate staff during this process while they denied my car proper care under a federal mandate. I bought this car to believe that Hyundai was a superior company in regards to warranties, price, and function as opposed to the more expensive counterparts of the same class. Which in the end has cost me way more, and almost my life. This car is dangerous and the company has done everything in their power to try to cover it up while placing blame on the very consumers that are believing in them to do better.

The contact owns a 2015 Hyundai Sonata. The contact stated that the vehicle was taken to a local dealer who performed an emission software upgrade. Later, while driving, the air conditioner blew hot air, the thermostat increased to high, and an engine overheating warning message was displayed on the instrument panel. The vehicle was taken back to the dealer, who diagnosed that the thermostat had failed and needed to be replaced. The thermostat was replaced, and the failure was remedied. The manufacturer was notified of the failure. The failure mileage was 74,000.

The contact owns a 2019 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle experienced severe overheating and excessive oil consumption. The contact also stated that there was a misfire in the engine even though the spark plugs and ignition coils were replaced. Due to the failure, the vehicle could not be driven with the air conditioning activated. Additionally, the engine was knocking and shaking abnormally, causing an oil leak and a smoke odor due to the oil burning. The vehicle was taken to a dealer, where an engine replacement was recommended. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 140,000.

I own a 2023 Hyundai Sonata sel. Over approximately three years, the vehicle experienced four separate incidents involving sudden loss of engine power and recurring fuel injector/powertrain problems. Three of these incidents occurred while the vehicle was being driven on interstate highways, creating serious safety concerns. The first incident occurred on xxx, on [xxx] [xxx]. My daughter was driving the vehicle at the time when it suddenly lost power while traveling on the interstate. She had to maneuver the vehicle to the shoulder under unsafe traffic conditions. The second incident occurred on xxx, on [xxx] near [xxx]. I was driving the vehicle when it again experienced sudden loss of power while traveling at highway speed. The third incident occurred on xxx, in [xxx]. The vehicle experienced another significant power-loss event and required roadside assistance. The fourth incident occurred on xxx, on [xxx]. The vehicle again experienced a sudden loss of engine power while I was driving on the highway. Despite multiple repair attempts, including repairs related to the fuel injectors, the same or substantially similar power-loss problem continued to recur. Because the vehicle has repeatedly lost engine power while being driven, including multiple incidents at interstate highway speeds, I believe this recurring condition presents a serious safety risk. I am reporting these incidents so NHTSA can evaluate whether this may represent a broader safety-related defect affecting this vehicle model. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2023 Hyundai Sonata 🔎.

I had the service campaign 9c2 and TSB 25-01-087h recall emissions update performed. I immediately noticed degraded performance with my vehicle. It's very jumpy/stuttery after I first start driving and feels less responsive. Even after driving for a bit, it feels like it drives and shifts oddly. It is not as smooth as it used to be. My car drove fine prior to the update and immediately felt different after the update. It's now been over a week and it's still like this, so it's not the engine computer adapting or something like that.

I was driving my 2014 Hyundai Sonata that I only had for 3 months when it just quit on me. I pulled over and seen when white smoke was coming from the wires.

My engine seemed to be consuming oil way to much I had to do a oil change at 61,000 recommend by tire plus but at 58,000 is when I had to change my oil I also noticed there is a buring smell and its also been leaking oil at times I went to get it checked out by a mechanic at tireplus but they also they are seeing that the oil consumption was not normal and they recommend a possible recall for it because it hazardous for how fast its consuming and the leaks.

See all problems of the 2017 Hyundai Sonata 🔎.

Since the 9c2 update on June 24, 2026, my vehicle has not driven the same. I'm experiencing clunky or harsh gear changes at low speeds, especially during stop-and-go driving. When I slow down and then accelerate again, the vehicle sputters or hesitates before responding. While driving at lower speeds, I also feel intermittent skips or small surges, almost like bubbles or brief misfires. These symptoms were not present before the 9c2 update, and they have noticeably affected the drivability of the vehicle. It was suggested the transmission needed time to "relearn" driving patterns, but it has been several weeks with no change.

Updated NHTSA complaint draftvehicle information: 2014 Hyundai Sonatavin: [xxx] incident date: xxx description of safety defect:while driving on xxx, the vehicle's engine experienced a catastrophic mechanical failure and completely shut off without warning, causing an immediate loss of motive power. This sudden engine stall created an extreme, hazardous traffic safety risk. A subsequent professional inspection revealed that the vehicle's odometer had been illegally rolled back and tampered with by the selling dealership (johny's auto center in 120 bleu hill Ave roxbury, MA) 02119 prior to purchase. The true, undocumented mileage of the engine is significantly higher than indicated, directly causing this sudden component failure. I am reporting this incident both as a critical vehicle safety defect and as a case of illegal odometer fraud. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

At approximately 130,000 miles, vehicle developed and internal coolant leak caused by a failed exhaust heat recovery system (ehrs) in the center muffler assembly, matching TSB 23-em-009h - a known manufacturing defect documented by Hyundai. Coolant has been slowly leaking internally into the exhaust system. The authorized Hyundai dealership initially failed to diagnose the internal leak and told me there was no leak and wanted to send me home. After pushing back, the internal leak was confirmed. If not caught, this defect could result in engine overheating or complete engine failure without warning. Hyundai motor America has denied goodwill coverage despite this being a documented manufacturing defect.

See all problems of the 2021 Hyundai Sonata 🔎.

I am writing about my 2013 Hyundai Sonata VIN: [xxx]. On [xxx] my vehicle experienced a knocking noise from the engine and the illumination of the check engine light. The car lost power and I was unable to drive it home. I had to call a tow service to have the car towed to alan turner Hyundai, 6501 pensacola blvd, pensacola, FL 32505. I spoke to a service writer at alan turner Hyundai. He told us that they could not help us and to contact Hyundai corporate office for help. We purchased this car brand new from alan turner Hyundai. We visited your web site and put in our VIN and the system stated that our vehicle was affected by the Sonata and santa fe sport engine recall campaign. We are an [xxx] with one car, and that car has stopped working. We need help in getting this car repaired under warranty via the Sonata and santa fe sport engine recall campaign. Thank you. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

On June 22, my 2015 Hyundai Sonata suddenly lost all electrical power without warning. The vehicle stalled and would not restart. There were no warning signs beforehand. After the incident, the car had no electrical power and was inoperable. Further inspection determined that the engine had failed and required replacement. I maintained the vehicle with regular oil changes and was unaware of Hyundai’s service campaign 953 (ksds update). I was never notified that this campaign needed to be completed, and I believe that failure to receive notice contributed to Hyundai’s denial of my engine replacement claim. I purchased the vehicle December 19, 2019. I was never notified by the dealer or manufacturer.

My 2016 Hyundai Sonata 2. 4l suffered an in-transit engine failure and entered emergency limp mode with an active p1326 rod bearing defect code, which is a recognized fire and safety hazard under NHTSA mandates. Service campaign 953 was successfully completed on August 12, 2019, qualifying the vehicle for a lifetime settlement engine replacement. Walser Hyundai brooklyn park (ro #257457) has issued an administrative denial based solely on a prior-salvage title flag from a cosmetic theft recovery. The manufacturer is actively stalling a court-ordered federal safety recall remedy based on an administrative title brand, despite the engine compartment being structurally original and undamaged. Hyundai corporate case #42869828 is open but unresolved.

Driving home from work on [xxx] (not a safe location)when my car lost power and engine light began to flash. I pulled off to the side of road and called my dad. He came with a code reader and said there was a code p1326. He cleared the code and car drove normally again. 2 days later it began to run rough. I was told about the engine recall so I called Hyundai corporate and told them this same story. I was advised to take to dealership and have the “rod bearings inspected” and shouldn’t matter that my dad cleared the code. The dealership(massey Hyundai MD) said it had a burnt valve and not part of warranty. But never checked rod bearings. When I called corporate. They said nothing they could do. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Rod bearing issue due to particles in engine causing engine to not accelerate as normal and jerk when goes over 10 mph can’t exceed 50 miles causing safety issues and knocking/clicking noise took it to Hyundai and was informed it is apart of the recall but wont replace engine my vehicle has all the same issues as the Hyundai recall but my VIN isn’t registered on the site for recall on carfax it shows a pattern of the previous owners being car in for maintenance and engine issues but engine never being replace under recall.

Check engine light solid/engine failure while driving. 2018 Sonata se purchased new in fall 2018. Around 50,000 miles started noticing oil level drop and had to add more before next scheduled change. Dealership service center said I just had to shorten the mileage between changes which didn't seem appropriate for a vehicle with 50,000 miles but I did. Continued to have oil consumption problem with no signs of leak, no burning oil smell or exhaust issues. Dashboard display would go off and when I immediately checked dipstick there was barely any oil so I'd add more then go in for full change. At 67,000 or so miles in June 2026, without oil display going off the engine light was now solid. Got to reputable service center near my home and oil was under a quart left yet the warning lamp hadn't gone off. They ran the engine error code p0304 and was misfire #4 cylinder and after compression test, #3 was very low and #4 very high. Not drivable at that point then towed to dealership so yes, available for inspection by NHTSA at the dealership. For now they claim a 'tune up' is needed for spark plug replacement, valve cover gasket replace and fuel induction service that's my cost to incur which seems to just be fixing the damage of an engine oil consumption problem not fixing the issue that caused the damage. The engine seized/stalled without warning while I was driving the vehicle (granted at low speed in my neighborhood when the engine light turned on). I would not say the engine warning lamp occurred prior to the engine fail, it happed at the same time. This should not happen for a vehicle with my mileage and regular maintenance. I looked up NHTSA for potential recall or other helpful information and started to see extremely similar scenarios to mine and wanted to add complaint as well. This is getting very expensive outside of whatever cost the dealer wants as a fix with rental car needed and tow services. Thank you for your consideration of this engine safety issue.

See all problems of the 2018 Hyundai Sonata 🔎.

Engine developed a loud rod-bearing knock at approx. 107,771 miles, consistent with the theta ii gdi connecting-rod bearing defect addressed by NHTSA recall 17v-226 (Hyundai recall 162). The vehicle was taken out of service and delivered to webb Hyundai, highland, in, on 06/13/2026, where it remains. Hyundai's own campaign records confirm recall 162 (gdi engine inspection/replacement) was completed on this VIN on 10/02/2017 and the ksds engine-monitoring software (service campaign 953) was installed 08/09/2019 - yet the engine has now failed in exactly the manner the recall was meant to remedy, indicating the recall remedy was ineffective for this vehicle. Hyundai motor America (case #42847594) has refused repair, citing a "branded title"; the only brand on the title is a "not actual mileage" odometer disclosure, not a salvage or rebuilt brand. Nhtsa guidance is that title branding is not a valid basis for denying a recall remedy. The defect poses a risk of sudden engine failure and stalling while driving. No crash, fire, or injury. Requesting NHTSA review of recall remedy effectiveness and of Hyundai's denial.

We had a recall done, campaign 92c, and every since then the car drives horrible. It's worse when cool, it sputters, and hesitates especially when excellerating. Even after warmed up it seems to slam in and out of gear at low speeds, even when foot is not on the gas. The drive is choppy. The dealership told us to drive it and let the transmission "learn" our driving patterns, but it has not resolved itself. Before campaign car ran smooth, now shuttering and sputtering.

I purchased my vehical at car culture in warren, OH. The dealer said to only take it there for maintenance, so I did as required. Whenever the check engine light came on I would bring it there and they would say it was a sensor and they fixed it. And one day it started miss firing and the light came on again. When I took it to the dealership, they said it needed oil to bring it in every 2 weeks to top the oil off. And so I did that and finally the car was getting worse at 122,000 miles. When I took it there they said it needed a new motor!!!. They never told me of a recall or a sensor replacement needing done by Hyundai. Iam now stuck with a $13,000 loan on a car worth nothing without paying $5,000 on a "possible" fix for their negligence. I have a [xxx] old son, fiancee, morgage and a job im struggling to get to, because I was never notified of a possible recall on my year, make and model of car. Please help me. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

My vehicle began experiencing excessive oil consumption several years before the engine failed. In approximately 2019, I reported the oil consumption to an authorized Hyundai dealership and expressed concern that my vehicle might have one of the known theta ii engine defects. I was told the knock sensor detection system (ksds) campaign had been completed and that my vehicle was not one requiring engine replacement. The excessive oil consumption continued. On June 6, 2026, the engine developed severe metal knocking, misfires, and became unsafe to operate. I was concerned the engine could fail completely or lose power while driving, creating a safety hazard for myself and others. The vehicle had to be towed to a Hyundai dealership on June 7, 2026. Hyundai of kennesaw inspected the vehicle and verbally advised that the engine failure was caused by connecting rod bearing failure. Although the dealership identified connecting rod bearing failure, Hyundai motor America declined to replace the engine and instead advised that it would not proceed with repairs because of the settlement provisions related to the vehicle's age and mileage. As a result, the vehicle remains inoperable. I am submitting this report because I believe this engine failure presents a significant safety concern due to the potential for sudden engine failure or loss of power while driving. I am also concerned that I reported symptoms years before the failure, yet the engine ultimately failed from the same type of defect associated with many Hyundai theta ii engines.

The contact owns a 2015 Hyundai Sonata. The contact stated that while idling at a stop light the vehicle suddenly stalled. The engine did not restart and the vehicle was pushed to a nearby parking space. During the failure no warning lights or messages had displayed. The cause of the failure was not yet determined. The manufacturer and local dealer were not yet contacted regarding the failure. The failure mileage was 123,000.

After the emissions 9c2 recall car hesitant when changing an Hyundai has knowledgement of the problem but don’t have a fix.

For my vehicle the check engine light has been on continuously throughout the last 6 months and mechanics are going to have to replace the thermostat. Multiple auto mechanics have indicated online that this is a very common problem with many Hyundai vehicles from 2020-2023 and can be a danger due to temperature control not being accurate for vehicles (code p2181). Many owners of these Hyundai vehicles have experienced this issue leading online and this issue should be made aware to Hyundai and the general public to see if this is something that needs to be made aware for the safety of drivers to determine if their vehicle is at an accurate temperature.

See all problems of the 2020 Hyundai Sonata 🔎.

The vehicle is stalling in the acceleration process. I can feel and hear the stall by the air conditioner going out or fading out when it happens while driving. Pressing the gas and it barely moves at times. Makes a noise now while running. Unknown to whether it's electrical or engine or transmission. Pull out in the traffic accelerating but the car wasn't moving at the pace it should have. Could have cause an accident when trying to cross on going traffic. Just got the vehicle 2 weeks ago. No one has inspected the vehicle yet. Going to have it looked at for recalls. No warning lights appeared to reflect an issue, but there clearly is.

See all problems of the 2025 Hyundai Sonata 🔎.

[xxx] [xxx] [xxx]; [xxx] [xxx] [xxx] date: xxx national highway traffic safety administration office of defects investigation (odi) subject: formal safety defect complaint – 2017 Hyundai Sonata theta ii engine failure, excessive oil consumption, intake/engine component failure and safety hazard dear sir or madam: I am submitting this formal complaint and request for immediate investigation into the dangerous and ongoing mechanical failures involving my 2017 Hyundai Sonata equipped with the theta ii engine. I believe this vehicle contains a serious manufacturing and/or engineering defect that presents a substantial safety hazard to consumers. My vehicle has experienced a pattern of progressive mechanical failure beginning with abnormal and excessive oil consumption, which appears to be directly associated with malfunctioning engine airflow and intake-related components. Specifically, the lower engine airflow system and intake functionality appear defective, placing excessive strain on the intake manifold system and contributing to cascading engine failures. As a result of these failures, the vehicle has experienced: severe and excessive oil burning/consumption intake manifold malfunction and abnormal operating stress suspected overheating and/or premature head gasket failure ignition coil failure and electrical shorting/misfires progressive engine deterioration rendering the vehicle unsafe and unreliable increased risk of sudden engine shutdown, stalling, fire hazard, or catastrophic engine failure while operating the vehicle has become increasingly unreliable and inoperable due to these conditions. These failures raise significant concerns regarding public safety, especially given the known history of complaints and recalls associated with Hyundai theta ii engine defects. I am deeply concerned that this vehicle may reflect a broader pattern of defective manufacturing, insufficient quality control. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Was driving the vehicle up berthoud pass on [xxx] . Was a few miles past berthoud falls and realized that the vehicle power diminished, noticed smoke coming from the engine. Pulled over and noticed leaking underneath the engine. It appears that a bolt came loose and punctured the engine block. After further research, it appears that this engine recall should have applied to my vehicle, but did not: [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

I am submitting this complaint regarding a serious safety issue involving my Hyundai Sonata. While driving under normal conditions, my vehicle suddenly entered a low-power ("limp") mode without warning. The vehicle would not accelerate beyond approximately 30–35 mph, creating a potentially hazardous situation in traffic. At the same time, the check engine light began blinking. The sudden loss of power significantly reduced my ability to maintain traffic speed and safely maneuver the vehicle. This condition could have increased the risk of a rear-end collision or other accident. I brought the vehicle to an authorized Hyundai dealership (fred beans Honda of abington ph# 215-392-9020) for diagnosis. The dealership confirmed that the vehicle stored diagnostic trouble code (dtc) p1326, related to the knock sensor detection system (ksds). According to the dealership, the vehicle entered limp mode as a result of this fault. The abrupt reduction in vehicle power and speed occurred without sufficient warning and created a safety concern. I am reporting this incident so that NHTSA can investigate whether this condition represents a broader safety defect affecting Hyundai Sonata vehicles equipped with the ksds system. Vehicle information: make: Hyundai model: Sonata model year: 2014 I request that NHTSA review this issue and evaluate whether additional action is warranted regarding vehicles experiencing dtc p1326 and associated limp-mode operation.