Power Train Problems of Hyundai Sonata - part 1

Hyundai Sonata owners have reported 786 problems related to power train (under the power train category). The most recently reported issues are listed below. Also please check out the statistics and reliability analysis of Hyundai Sonata based on all problems reported for the Sonata.

1 Power Train problem of the 2020 Hyundai Sonata

Failure Date: 08/10/2026

I am submitting a safety complaint regarding a recurring, unresolved electrical defect in my 2020 Hyundai Sonata sel. The vehicle fails to recognize when the ignition is switched off, leaving core vehicle systems active and causing severe parasitic battery drain that leaves the car immobilized. ?description of the problem: ?false "on" status: after parking, turning off the engine, and exiting the vehicle, the car continues to register as though the ignition is still active/on (accessories, cluster, or vehicle network remain awake). ? severe parasitic draw: because the vehicle fails to shut down its electrical circuits, the 12-volt battery repeatedly discharges overnight or while parked for short durations. ?battery replacement did not resolve issue: the 12-volt battery was replaced with a brand-new unit to eliminate typical wear, yet the drain and false "on" behavior persisted immediately. ? frequency: the vehicle frequently fails to start, requiring constant jump-starts or roadside assistance to operate. ?safety hazard: this defect creates a direct safety risk by repeatedly stranding the driver without warning in public locations, traffic stops, or remote areas. In addition, an electrical system that fails to enter a sleep state creates a potential hazard for component overheating, failure of electronic security and locking systems, or total electrical failure while attempting to restart or operate auxiliary safety equipment. Other Hyundai owners have reported identical issues where the body control modules or ignition logic fail to power down. ?corrective action requested: I request that the NHTSA investigate this electrical shutdown defect across the 2020 Hyundai Sonata model year to identify whether a faulty body control module (bcm), Smart key receiver, or ignition switch relay requires a safety recall and software or hardware remediation. Battery replaced on 09/04/2026 car inspected/diagnosed by Hyundai dealership on 09/03/2026.

See all problems of the 2020 Hyundai Sonata 🔎.

2 Power Train problem of the 2021 Hyundai Sonata

Failure Date: 07/31/2026

Going down the road driving the car lost power and went in limp mode with no warnings on the dash at all!.

See all problems of the 2021 Hyundai Sonata 🔎.

3 Power Train problem of the 2013 Hyundai Sonata

Failure Date: 07/24/2026

Car stalls when I’m at a red light, very dangerous.

See all problems of the 2013 Hyundai Sonata 🔎.

4 Power Train problem of the 2018 Hyundai Sonata

Failure Date: 07/14/2026

I recently had the 9c2 emissions recall update performed on my car, and since the update my car drives like total garbage after a cold start. It hesitates to accelerate, it bucks when trying to accelerate, and it’s to the point the engine is about to stall. I took it back to the Hyundai dealership and they said they are aware of the issue, but there is no fix from Hyundai at this time. This is a major safety concern, as the car barely wants to accelerate after a cold start. Please have Hyundai fix this safety issue.

See all problems of the 2018 Hyundai Sonata 🔎.

5 Power Train problem of the 2020 Hyundai Sonata

Failure Date: 07/10/2026

My vehicle while driving, it is jerking and shaking. When I come to a stop, the cars rpms go up and down while the car is shaking. When I pressed the gas pedal to accelerate the car will not accelerate as normal and the car jerks as I’m driving it. The rpms rev up and down without any pressure placed on the gas pedal. The check engine light came on. The miles per hour only allows me to put one digit. I wanted to clarify that the problem is occurring anywhere between 0 mph to 65 mph when these the car jerks and shakes and the rpms go up and down without me pressure on the gas pedal.

6 Power Train problem of the 2015 Hyundai Sonata

Failure Date: 07/01/2026

Vehicle: 2015 Hyundai Sonata, 2. 4l theta ii gdi engine mileage at time of incident: [ 93k date update performed: June 2026 dealer/location where update was performed: fitzgerald Hyundai gaithersburg, MD description of problem: after my vehicle received the ecm software update issued under Hyundai service campaign 9c2 (ecu software update for theta ii emissions improvement, TSB 25-01-087h / 26-01-013h-1), the vehicle began exhibiting noticeable jerking/hesitation during acceleration that was not present before. For this vehicle this happens consistently after a cold start then does not happen again.

See all problems of the 2015 Hyundai Sonata 🔎.

7 Power Train problem of the 2023 Hyundai Sonata

Failure Date: 06/30/2026

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 🔎.

8 Power Train problem of the 2018 Hyundai Sonata

Failure Date: 06/14/2026

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.

9 Power Train problem of the 2023 Hyundai Sonata

Failure Date: 06/13/2026

The contact owns a 2023 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the transmission shifted into neutral(n) and failed to shift into park or drive on three occasions. The vehicle was restarted. After restarting the vehicle, the vehicle was shifted into drive, and the contact continued driving. The message that the vehicle could not be shifted into other gears was displayed. The vehicle was originally purchased in another state. The vehicle was taken to the local dealer to be diagnosed. The dealer determined that the battery and fuel injector pump needed to be replaced. The vehicle was repaired; however, the failure recurred. The manufacturer was not contacted regarding the failure. The failure mileage was approximately 50.

10 Power Train problem of the 2013 Hyundai Sonata

Failure Date: 06/06/2026

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.

11 Power Train problem of the 2016 Hyundai Sonata

Failure Date: 06/02/2026

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

See all problems of the 2016 Hyundai Sonata 🔎.

12 Power Train problem of the 2020 Hyundai Sonata

Failure Date: 06/01/2026

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.

13 Power Train problem of the 2017 Hyundai Sonata

Failure Date: 05/27/2026

[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).

See all problems of the 2017 Hyundai Sonata 🔎.

14 Power Train problem of the 2014 Hyundai Sonata

Failure Date: 05/25/2026

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.

See all problems of the 2014 Hyundai Sonata 🔎.

15 Power Train problem of the 2025 Hyundai Sonata

Failure Date: 05/20/2026

The contact owns a 2025 Hyundai Sonata. The contact stated that while the accelerator was depressed, the vehicle hesitated, jerked, and failed to accelerate as intended. The failure occurred while driving from a stop and while driving at various speeds, causing the vehicle to decelerate during the failure. While depressing the brake pedal, there was a rubbing or grinding coming from the vehicle, and the braking was rough. There were no warning lights illuminated. The vehicle was taken to the dealer, who was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not made aware of the issue. The failure mileage was approximately 38,000.

See all problems of the 2025 Hyundai Sonata 🔎.

16 Power Train problem of the 2012 Hyundai Sonata

Failure Date: 05/19/2026

Knock sensor needs to be replaced upon evaluation of an inspection on March 27, 2026. It failed a mission codes and upon my understanding the knock sensor one circuit range performance pink wonder single sensor is an engine failure as well as I did an odb test myself on may 19 of 2026 for the knox sensor as well and the check engine dominator reading at 2111 the the code indicated that bank one knox and electrical circuit was out of it upper range or had it perform problem for a predetermined period of time and the code is p0326 and the secondary dtc is a combustion vibration sensor a circuit range performance which affects the powertrain. Also, I have switches with the electrical features in the vehicle as far as the abs and the steering wheel controls and glitching for the cigarette adapter and plug-in area as well on top of the rear passenger side window, having issues with going up and down.

See all problems of the 2012 Hyundai Sonata 🔎.

17 Power Train problem of the 2016 Hyundai Sonata

Failure Date: 05/16/2026

Went from 65 and dropped down to 40 going up grades on the freeway. Started shaking, check engine light went on and electric battery disappeared from dash. Got to top of grade, went back to normal. Problem repeated on next grades. Car had just left dealership lot an hour prior where it was safety inspected and they said all was fine. Took back to dealership for inspection and they said that there were no codes showing for what happened and all was well with the vehicle, when obviously it was not.

18 Power Train problem of the 2018 Hyundai Sonata

Failure Date: 05/14/2026

The contact the contact stated that when taken the vehicle for a service campaign repair and shortly after went for recall r the vehicle does not run properly on cold starts, the rpms increase rapidly and slow down, vehicle jerks forward once beginning to drive. . The vehicle does not have this issue once the vehicle is warm. The manufacturer was not notified of the issue. The approximate. Failure mileage was 47,575.

19 Power Train problem of the 2015 Hyundai Sonata

Failure Date: 05/10/2026

Car stopped in the middle of the road , with warning beeps and warning messages on the dashboard saying "check charging system" . Engine was still running but even though I did accelerate - car did not move . I put on the emergency lights and turned off the car . Turned on the car few seconds later and was able to drive then but the check engine light was on. Slowly drove back to the home as I was less than a mile from the home. It happened on a local road with speed limit of 35 mph and thankfully vehicles behind me stopped until I pulled over. Me and and 7 year old kid was in the car at the time of this incident.

20 Power Train problem of the 2012 Hyundai Sonata

Failure Date: 05/01/2026

P1326, rod bearing failure and seizure of motor without warning.

21 Power Train problem of the 2016 Hyundai Sonata

Failure Date: 04/29/2026

My 2016 Hyundai Sonata is experiencing severe oil consumption due to a known Hyundai engine defect. The engine burns oil rapidly and loses more than a quart between oil changes. This creates a safety hazard because the engine can stall, seize, or fail while driving. The Hyundai dealership did not perform the official Hyundai oil-consumption test. They only checked the dipstick, noted the oil was low, and submitted a request for a paid combustion cleaning. Hyundai declined to pay for the cleaning, and the dealership is refusing to perform the required oil-consumption test unless I pay $750. 00. Hyundai corporate also refused to authorize the test, stating the vehicle is out of warranty, even though this is a known engine defect affecting many Hyundai vehicles. Without the official test, Hyundai will not review the engine defect or consider a goodwill engine replacement. This is a safety issue because the engine can fail without warning. The dealership and Hyundai are refusing to perform the required diagnostic test unless I pay $750, and refusing to review the defect without that test.

22 Power Train problem of the 2016 Hyundai Sonata

Failure Date: 04/15/2026

The following mandatory software update was performed on my vehicle: ecu software update for theta ii emissions improvement (service campaign 9c2). After this update my vehicle drivetrain is quite erratic. In particular when the engine is cold it appears to jerk even when in parking gear position. When cold the drivetrain experiences erratic gear shifts. This provides little confidence when driving and could result in safety issues when merging into traffic. Once the engine has reached its normal operating temperature it still makes occasional gear shift that are jerky and probably not good for the transmission. This vehicle had a very smooth transmission prior to the ecu software update, now I am hesitant when I need to merge into traffic, since I am not sure it will select the correct gear when accelerating. I have reported this to the dealership and Hyundai corporate service center and both indicate that when the engine is cold that the drivetrain can act strange, but once it is up to temperature it should be smooth. I have looked on the web and noticed multiple Hyundai owners with similar engines reporting the same issue after this software update. Hyundai may have satisfied the epa requirements with this software, but they may have a created a safety issue for the vehicle operator and their passengers.

23 Power Train problem of the 2021 Hyundai Sonata

Failure Date: 04/15/2026

Massive loss of coolant in closed loop cooling system heat soak. Fail safe mode.

24 Power Train problem of the 2018 Hyundai Sonata

Failure Date: 04/04/2026

Engine blown out malfunction took two dealer Hyundai folsom lake stated rings are bad sludge buildup in engine and stayed at Hyundai motor America denied engine replacement due to knowledge under theta two engine extended warranty settlement of 150,000 mi 15 years I'm still within warranty but are still being denied had numerous of issues with vehicle oil consumption knock knock sensor replace and other maintenance done since purchase vehicle brand new in 2018.

25 Power Train problem of the 2016 Hyundai Sonata

Failure Date: 03/25/2026

I have a car covered by the theta ii settlement. Engine, fuel system. Metal shavings found in oil and oil is diluted with fuel and oil if overfilled 1 inch above full mark on dipstick upon pickup from dealership. The vehicle is available for inspection at my residence; however, it is currently grounded as a known safety hazard. The vehicle is exhibiting symptoms of imminent engine failure (audible knocking, p0011 code, and oil dilution). Despite being shown evidence of this(photo and video of oil overfill and watery viscosity) , the manufacturer instructed me to continue operating the vehicle, placing myself, and other drivers at risk of a high-speed collision or vehicle fire. The symptoms (p0011 code and engine noise) were confirmed by an independent mechanic on March 25th 2026. However, during the official bearing clearance test (bct), the dealership intentionally overfilled the engine oil by 3 quarts (documented via photograph) to muffle mechanical noise and artificially pass the diagnostic and issued a pass on all inspections despite the oil hazard. Hyundai corporate case manager nikulmar dhabi has admitted on record that the dealer was out of compliance by "being outside the standard notification time" yet they refuse to provide a safety-compliant remedy. Warning symptoms & appearance: symptoms first appeared months ago when I repeatedly got a p0011 code, however on March 24th 2026 I received an engine light with a p0011 and the car going into limp mode while I drove. Warning signs included a persistent check engine light (p0011) and audible metallic knocking. Upon checking the oil myself after the dealer "inspected" it, I discovered the oil was 3 quarts over the "full" line, which is a deceptive practice used to mask rod bearing failure.

26 Power Train problem of the 2018 Hyundai Sonata

Failure Date: 03/21/2026

I bought a 2018 Hyundai Sonata a few years back. No warranty. Used. 110,000 miles. A few short months after I purchased it, it stopped working. I took it back to the same dealership where I purchased it and they said they had to replace the coil packs and spark plugs and clean something in the engine out because there's a defect in the engine. I paid $500. Fast forward a few months later. Same thing happens. I take it to an auto repair shop because it's cheaper and the mechanic says he deals with these same issues with other customers who have similar year, make, and models. This pattern continues to this very day. It broke down while I was working my 2nd job. I have a daughter. She plays sports. I have a second job. I need this problem completely alleviated as quickly as possible. Like a lot of the american public, I don't have extra money to keep up with anything beyond the normal maintenance of my vehicle. I keep it up to date with all oil changes. What can you do to get me a vehicle I can trust and it not break down every couple months and cost $300-$600 each time? I don't have good credit (I'm working on that) I have medical issues that I have to visit my doctor for every 3 months. I have the loan through capital one and they don't offer refinancing. My father who has passed was a car salesman his entire career. I just need reliable transportation and if it's a motor problem like they say then I shouldn't be liable to fix it. The manufacturer should. Please let me know if you need any service records from me. Oh and I also have to put about $20 worth of oil in it every week or so between oil changes. My local oil change guys unfortunately know me very well.

27 Power Train problem of the 2015 Hyundai Sonata

Failure Date: 03/16/2026

The incident began following a routine maintenance visit on March 16, 2026, and has been a continuous, ongoing safety hazard every single day since. While the vehicle was in for routine brake service and an oil change, the dealership automatically applied an open, manufacturer-mandated ecu s/w update theta ii (26-01-013h-1) under service campaign 9c2 emissions (code np001-sc9c2) without my prior knowledge of its drivability side effects. This software flash directly compromised the vehicle's powertrain logic, creating two notable, daily safety failures. First, within the first 5 minutes of engine startup, and most pronounced on every cold engine startup, the throttle delivery is highly erratic, causing uncommanded low-speed surging. In a specific incident in a parking lot following a cold start, I accelerated to approximately 15 mph and completely removed my foot from the accelerator pedal to coast. Instead of slowing down, the vehicle unexpectedly lunged and pulled ahead forcefully against my intent. Second, even after reaching full operating temperature, the vehicle completely loses safe and predictable engine braking at greater speeds; when lifting off the gas pedal, engine rpms aggressively drop, causing the vehicle to coast freely as if in neutral. Re-applying the accelerator causes a violent "phantom shifting" downshift and a hard transmission lockup. My safety and the safety of others are put at risk every time the vehicle is driven. The low-speed throttle surging creates an ongoing risk of hitting pedestrians or cross-traffic, while the permanent loss of predictable engine braking drastically extends stopping distances. No warning lamps or diagnostic trouble codes (dtcs) appeared prior to or during these continuous failures. The vehicle remains available for inspection.

28 Power Train problem of the 2018 Hyundai Sonata

Failure Date: 03/14/2026

Following completion of service campaign 9c2 (ecu software update, TSB 25-01-087h) at a Hyundai dealership, my 2018 Sonata immediately exhibited drivability changes that were not present before the service. Symptoms include altered shift timing, hesitation, and rougher throttle response — particularly noticeable during the first several minutes of driving. These symptoms began on the first drive after the recall update was applied and have been consistent since. The vehicle was returned to the dealership for inspection. No underlying mechanical issue was found, confirming the drivability change is directly attributable to the ecu software update. The vehicle has been maintained strictly per Hyundai's manufacturer-recommended schedule and had no prior drivability issues. I am aware that numerous other owners of theta ii-equipped vehicles (sonata, santa fe, tucson) have reported identical symptoms following 9c2. At least one dealership has reportedly acknowledged this as a known post-update issue that Hyundai is working to resolve. The altered throttle and shift behavior poses a safety concern, as unexpected hesitation during acceleration affects predictable vehicle control in traffic. The vehicle is available for inspection upon request.

29 Power Train problem of the 2015 Hyundai Sonata

Failure Date: 03/12/2026

In March 2026 Hyundai did an emissions update campaign 9c2. Since that update my 2015 Hyundai Sonata se has run rough and shifted hard. Hyundai stopped doing the update in may 2026. Hyundai has not provided any update to fix the problem they created. I am worried the update is damaging the motor and transmission of a car that was running just fine prior to the update.

30 Power Train problem of the 2016 Hyundai Sonata

Failure Date: 03/09/2026

This complaint is not related to the existing recall associated with this vehicle. The vehicle is experiencing a serious loss of power and acceleration issue. The car is unable to accelerate past approximately 60 mph. When pressing the accelerator fully, the vehicle does not respond or increase speed. While attempting to accelerate, the engine rpm increases and then suddenly drops repeatedly, causing the vehicle to struggle to maintain speed. This behavior is consistent and occurs during normal driving conditions. This creates a dangerous situation, especially when merging onto highways or attempting to accelerate in traffic, as the vehicle cannot respond when needed. The issue has occurred multiple times and makes the vehicle unsafe and unreliable to operate.

31 Power Train problem of the 2015 Hyundai Sonata

Failure Date: 02/27/2026

The bearing failure from the metal debris had been progressing silently for a long time. You can’t feel or hear it happening gradually. Then at some point the damage crosses a threshold where: ?the oil can no longer circulate properly ?the crankshaft bearings completely fail ?internal metal parts make contact with each other ?everything locks up instantly.

32 Power Train problem of the 2023 Hyundai Sonata

Failure Date: 02/25/2026

This is an extremely common issue plaguing Hyundai & kia vehicles with the theta iii 2. 5l turbo engine, such as kia k5 gt, Hyundai sante fe, Hyundai santa cruz, & Hyundai Sonata n-line. Its a failing itm (integrated thermal management) unit or otherwise known as an itms unit. There is a rod within the itm that prevents proper control of the flow of cooling the oil and engine coolant of the engine. Results in cooling issues, such as a cold lower radiator hose while the engine is hot, or 'limp mode' during acceleration, that causes a sudden loss of power while trying to merge on the expressway. There has been other kia models and years that have had TSB's related to fixing this issue, but Hyundai has released nothing. I have uploaded an example of one of the TSB's that do not apply to my car. Technical symptoms often include: fans running 100% full duty (high) while the lower radiator hose stays cool. Or fuel dilution or a 'rich' running engine. Because the engine is overcooling that keeps the car's fueling rich and in a open loop mode affecting emissions and contaminating oil. Personal details of exactly what happened when I noticed mine was failing. I ran home on my lunch break, and while accelerating on a ramp to get up on a highway, my car started beeping and flashing "engine overheated" and I immediately let off the gas with preparation to pull over. The second I left off the gas, the coolant temp within 1-2 seconds went from a little over 3/4 the way up the gauge back to normal a little below half temp. I resumed driving a 3 mile drive back to work, with it showing normal temps the rest of the way. I popped the hood when I got to work to see if coolant was low, and it was completely normal, a little over halfway between the min/max lines. The car continues to run hot, often with the cooling fans running at 100%.

33 Power Train problem of the 2024 Hyundai Sonata

Failure Date: 02/25/2026

Sudden loss of acceleration. This occurred while making a left turn across traffic from a stop. At approximately 7mph the car would not accelerate any further. I was luckily able to coast the vehicle into a center turn lane. Upon coming to a stop I was unable to get any acceleration. The vehicle was turned off and turned back on again and operated normally. There were no trouble codes displayed.

See all problems of the 2024 Hyundai Sonata 🔎.

34 Power Train problem of the 2023 Hyundai Sonata

Failure Date: 02/18/2026

Car was parked, full stop, doors shut, seatbelt on. Foot on brake. Car then seemed to lurch forward by itself forward hitting parking cement block. Put in reverse to back away and car stayed still. . . Then I tapped the gas again to back up and insted vehicle plowed forward. Instead. Of reverse . . . Went over the parking block and hit concrete beam in front, when the car should have backed up in reverse. I'm a person who drives speeed limits, and ulta careful when I drive, and parked at this place/spot for years. This has never happened not sure why it did. No injuries or other people involved thank god, but scared the heck out of me. Wracking my brain, my recalls and software and service appts are up ro date. Nothing out of ordinary that day. I'm confused and shaken, why the first lurch forward and why did going in reverse move it forward? ugh. It drove home fine. Commute to work daily for years, no issues. All I can guess is gear didn't click to reverse and was somehow in drive? ive been going over the possibilities in my head for human error but they dont make sense - again I've been driving for 40 years. If it happens to other models, would love to know! car will go to repair tomorrow as "my fault" via insurance, hoping they can see more if any error codes, to at least say if reverse didn't engage or something else happened. May have been human error but it's so out of the ordinary for me. Thanks!.

35 Power Train problem of the 2021 Hyundai Sonata

Failure Date: 02/11/2026

Vehicle suddenly lost heat in 30 degree weather. No warnings, check engine light, or temperature gauge indicators came on. Lucky made it to a parts store and found out I was extremely low on coolant. Bought coolant and put it in. Made it back to the house and was immediately low again. No visible leaking. Oil was completely fine (1 gallon of coolant would have have left some kind indicator). Realized it was more than likely the ehrs. If this happened during the summer, my engine could have blown due to a poor design causing a major accident.



☘ Sonata Service Bulletins
⚑ Sonata Safety Recalls
☤ Sonata Defect Investigations