2023 HYUNDAI SONATA Engine Problems

My car was having an issue where it was losing all the coolant, causing my engine to overheat twice while driving down the highway. Unfortunately I couldn't find a leak anywhere and there was no fluid leaking in my garage. I lost an entire reservoir of coolant overnight. After taking my car to the dealership to get repaired, I was told that it was leaking my coolant into the exhaust system and burning it up. I was also told "it was a know issue, they had a bulletin from Hyundai on how to fix the problem, and Hyundai completely redesigned the part to stop the leak and it had to be special ordered." I was without my car for a week and left with a $1300 bill as apparently it was not covered by my warranty. I have no idea how a known issue is happening so frequently that requires a nationwide bulletin and a part redesign, yet somehow is recalled. Especially considering it left me stranded on the side on the side of the highway in Indiana during a snow storm but someone seriously needs to investigate it.

I am reporting a serious coolant system defect on my 2023 Hyundai Sonata Hybrid with about 13,500 miles. The vehicle develops an internal coolant leak while driving. Coolant burns off and white steam/smoke comes out of the exhaust, especially during acceleration. When this happens, the coolant level drops quickly, the interior heater stops working, and the car soon displays an engine overheating warning, forcing me to stop driving. This has happened multiple times and makes the vehicle unsafe. When I checked under the hood, coolant was at a low/empty level after overheating events. The car becomes undriveable once the alarm appears. I took the vehicle to a Hyundai dealer, and even though the vehicle is only 2 years old, they told me it was “out of warranty.” I had to pay about $1,500 for repairs, and since the dealer refused a loaner, I paid $250 for a rental car. I called Hyundai USA on 9/13/2025 and opened Case Number XXX. Hyundai acknowledged they are aware of coolant issues on the Sonata Hybrid but said no recall exists. This issue appears widespread. Many other owners report the same symptoms: white exhaust steam, coolant smell, coolant loss, no interior heat, and engine overheating. Hyundai released TSB 23-EM-009H, describing a failure where coolant leaks internally in the Exhaust Heat Recovery System (EHRS), causing white smoke and overheating—matching my symptoms exactly. This defect is a safety hazard because overheating can occur suddenly while driving, risking engine damage or breakdown in traffic. I request NHTSA investigate this issue as a potential recall-level defect on the 2023 Sonata Hybrid. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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.

The fuel injectors failed on my Hyundai Sonata in two instances. Once on 5/23/24 and once on 9/7/25. During the first instance, I was driving on a local road when the accelerator stopped working and the engine started sputtering. We were fortunately able to stop at a nearby parking lot before the engine completely stopped working. During the second instance, I was also driving through a local road when the accelerator stopped and the engine started sputtering again. This time, we weren't able to reach a safe stopping point and the engine died on the road. My family was with me at the time, so we had to push the car in neutral to the closest safe space. In both cases, our safety and the safety was others was put at risk as the car become unable to accelerate, and the car stops moving. We had to get out on the road and push the car with oncoming traffic. The problem was confirmed by the dealer in both cases, and they replaced the fuel injectors in both cases. So far, they've replaced 3 out of the 4 fuel injectors so I still drive in fear of another fuel injector causing a breakdown while I'm driving. There were no warnings or symptoms prior to the failure so there was no way to know to stop driving and to stop in a safe spot. We were fortunate to be able to move the car to a safe place for both instances, but if this had happened on the highway or secluded location, our lives could've been at risk. I've requested Hyundai to replace the last fuel injector but they're refusing to do so. I only feel safe driving in local roads or short highway trips as I fear for the reliability of my car, my safety, and the safety of others.

I was driving my 2023 Hyundai Sonata with 22,000 miles on I-96 near Grand Rapids Michigan at or slightly below the speed limit of 70 MPH. Suddenly, with no advance warning of any kind, the engine shut down. I was able to coast and maneuver to the right shoulder of the road while avoiding traffic, including a large tractor trailer that almost hit us. The vehicle than had just enough power to get off the next exit and on a local side street. At that point the vehicle would not restart and you could smell a strong odor of fuel. I called Hyundai and they sent a tow truck to take it to the nearest dealer. (I am 700 miles from home). The dealer's service department diagnosed the problem then replaced the fuel injectors still under warranty.

Coming home from work I stopped at a red light and when I tried to accelerate the vehicle was surging and jerking shaking and wouldn't pick up speed 2 min later the check engine light appeared flashing thankfully I was 5 min from home got the car towed the next morning to hyundai dealership said it was an cylinder misfire the car only has 30,000 miles on it

On June 4 as son was turning, the car started shaking & went to park. He managed to slip into a nearby parking spot & tried to reverse. The car turned on, put into reverse & then after about 2 seconds it went to park & stopped. This happened several times. It was towed to the dealer who today, June 10, reported it was a transmission flaw. The car was being driven at about 30 mph on a 2 way street. Had it been on the interstate at a higher speed, it may have caused a dangerous situation with a sudden stop.

2023 Sonata N-Line, complete loss of power while driving on seven (7) occasions over the past year. In all cases above 60mph creating a dangerous condition to myself and fellow drivers while attempting to pull to the side of the road while rapidly losing speed. In all seven (7) cases, the DTC code is P065312. I have asked the dealership to note the recurring issue in my service records and I have reached out to Hyundai, mostly so that if I am involved in a serious accident because of this issue, there is a paper trail for legal purposes. The dealership folks are nice but basically unless the car rolls into the dealership with smoke pouring out of the engine, they want to charge a diagnostics fee and keep the car for multiple days which isn't helpful because like most, I need the car and the issue is extremely sporadic. It is disappointing and I hope Hyundai takes note and provides remedy for the issue sooner rather than later as this is my sixth (6th) Hyundai vehicle and really do like the car otherwise. All incidents below: 01/23/2025 - 9531 miles 01/20/205 - 9128 miles 12/15/2024 - 5500 miles 12/13/2024 - 5374 miles 11/22/2024 - 2409 miles 01/12/2024 - 568 miles 01/08/2024 - 554 miles

For like the fifth time while I'm driving the car just dies. I can be going 55 I can be going 70 and the dashboard lights up like a Christmas tree and the car just dies. I have to pull the car over to the side and I have to turn it off and restart it again. And then about 3 days later the check engine light will go away. This seems like a software issue but Hyundai and my local dealer cannot help me I'm going to get killed in this thing. I can't take it on the highway I can barely take it down the street because it could go out on me while I'm driving and I could be in the middle lane and I could get killed. They tell me they can't replicate the issue but it's a software issue somebody needs to do something before I get killed. Every single light on the dashboard turns on and the engine just dies. This is like the fifth time this has happened. I think this car is a lemon but no one will help me.

I was driving on the interstate at interstate speeds and the car started to lose power. I was able to steer the car to a safe location and call roadside assistance. It appears that the engine control system had a failure in one of the control modules. The problem was reproduced at the time that I dropped the car off with the service center. The history of the issues for the vehicle are available. My safety was put at risk because the car lost power at high speed and I was only able to limp to a safe location. No warning lights happened until the issue was already taking place. After being notified by my Hyundai app, I was able to discover that the vehicle had a history of having this code (I have only owned the car for 32 days)

On two separate occasions, one at @9500 miles and the next at @19,000 miles the car engine started shaking and lost all power while driving. Unable to steer car. Both times towed to dealer and they say it needs new spark plugs and need to clean cylinders. They do not know root cause of problem and have not done any testing of the engine, no leak/compression testing. Dealer refuses to cover cost of repairs saying out of warranty but cannot give any assurances this won’t happen again. I’ve requested they contact Hyundai engineers to find out what’s causing this and, to date, they’ve done nothing. Vehicle is unsafe to drive and is still at dealership with no reason to underlying issue.

The car would not accelerate, nor switch gear while I'm driving middle of the highway. The car engine started to shake after my car wouldn't switch gear. The car engine would not start after turning the car off and caused a engine misfire. The transmission gear has a hard time switching gear from 0-40mph. This same incident occurred twice since purchasing the car in late November 2022.

I have had three occasions where the dashboard lights would flash and the car would lose all power. The first occasion occurred on December 29th at around 12:20 pm at a crowded intersection. The dashboard lights lit up and all of a sudden the car had no power at all. I managed to get it through the intersection and pull it off to the side of the road. To start it up I have to TURN OFF THE CAR by putting it in park and start it up again. This is stressful and terrifying to think about if this had happened on the freeway. Additionally, I took the car to get serviced and was charged a $1,800 bill to fix it in January. This repair took two weeks to complete. The car has since turned off two additional times on February 15th going down a hill at 40 mph and March 26th on a mountain road going 60 mph. I am very concerned this will happen on the highway and I will get into a serious accident or worse. To make matters more difficult, I have taken the car back to the Hyundai dealer again to have it looked at in April and will most likely be without the car for at least another week. I bought the car brand new and the check engine light has gone off four times since then.

2023 Hyundai Sonata N-Line bought on [XXX]. Engine Control System failed 2 times w/in first 4 months. 1ST ENGINE INCIDENT ● [XXX] (Approximately 1:30 p.m.) ○ I was driving (1,949 miles on odometer) at an intersection when car lost power, lights on dashboard starting flashing & ignition shut off in the middle of intersection. ○ On dashboard notification stated “A possible condition with your engine control system has been detected with your 2023 Hyundai Sonata [XXX] ) on [XXX] at 1:25 p.m. A full system check is recommended to be done soon”. I also received notification via email. ○ Couldn't get appointment until [XXX] Cesar advised me they did diagnostic test & test drive & couldn’t find the problem. They made no repairs & made a notification in system of this problem. He stated that if it happens again to bring the car back. 2ND ENGINE INCIDENT ● [XXX] ○ My husband & I were driving (4,177 on odometer) & I was pulling out of a side street to make a left hand turn into a busy 4 lane street & as I drove ½ way across street my car lost all power, lights on my dashboard started flashing, ignition shut off & two cars were driving towards us about to T-bone us my driver's side. Cars braked suddenly to avoid hitting us. ○ On the dashboard of my car was a notification stating “A possible condition with your engine control system has been detected with your 2023 Hyundai Sonata [XXX] ) on [XXX] at 1:15 p.m. A full system check is recommended to be done soon”. I also received this notification via email. Dropped car off at Fontana Hyundai on [XXX]. Did diagnostic test & engine specialists inspection; couldn't find problem They said we will replace this part and hope it doesn't happen again. How do you put someone back in a car when you haven't diagnosed the problem; that's a serious safety issue, my life is endangered. Supposed to pick car up [XXX]. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Driving going 30 mph, vehicle stopped accelerating. Error code was Engine Control System failure. Codes P2178, P0301 and P0087F0 were shown at dealership. Car was taken to dealership for repairs where the fuel injector on cylinder #1. 16 days after receiving car back, we went to start the car and it wouldn't start. After several attempts, gasoline began spewing from the car leaking an entire tank of gas on our garage floor and driveway. Very dangerous! Being towed to dealership again today.

Vehicle’s front collision sensor popped up on dash, vehicle lost all power. Almost was hit by a group a semi trucks hauling a wide load that wouldn’t have been able to stop in time. This is the 3rd time it has happened in a week and a half.

The contact owns a 2023 Hyundai Sonata. The contact stated that on two separate occasions while driving at various speeds, the vehicle started to shake, and the vehicle lost motive power. The vehicle was pulled over to the side of the roadway and turned off. The vehicle failed to restart on both occasions. The vehicle was towed to a dealer where it was diagnosed that the fuel injector needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The failure mileage was approximately 11,000.

Mileage: 11,000

Purchased a new Hyundai 2023 Sonata from McGovern Hyundai Rt 2 May 22, 2023. After two weeks of driving the vehicle, I noticed it hesitates when I push down on the gas pedal. I had planned to have the dealership take a look but have a very busy schedule, the issue continued each time I drove the car to the point it was hesitating, basically pausing as I cross intersections. On the 26th of July I was driving on the highway, as I started to experience issues when stepping on the gas. Entering a tunnel in Boston, I pushed down on the gas pedal and noticed the car was decelerating, I was losing speed, in a panic in the center lane of the tunnel, I was able to get the car over to the far right. The car was shaking aggressively then finally just gave out and I called 911. They towed the vehicle to the police headquarters, I called Hyundai for assistance. Had some hiccups but two days later they were able to service the vehicle, supposedly found a faulty fuel injector. They changed out the 1 faulty injector test drive and said the problem was fixed. I picked up my car on July 28th 2023. There is something still wrong with the car, it still has some hesitation and now misfires. Have not heard from Hyundai, I was assigned a case manager and told someone would follow up, no one has reached out. So lucky my children were not in the car and that i'm safe. I could have been killed, others could have been hurt/killed. This should not happen to brand new cars.

When I approach an intersection to stop my car auto shut off engages. When trying to hit the gas to release my car from auto shut off the emergency auto shut off engages and I must put my car in park. Turn the ignition to off and then crank my car back all the way on. Release the park and drive. This happens intermittently for several weeks and I’ve almost been rear ended several times. I have taken the car to a Hyundai dealership for the issue and they tell me nothing is wrong.

The contact owns a 2023 Hyundai Sonata. The contact stated that while her daughter was driving at an undisclosed speed, the vehicle lost motive power. An unknown warning light was illuminated. The vehicle was towed to the dealer; however, no error code was retrieved. The failure recurred while the contact was driving at 60 MPH. The vehicle was then taken to Serra Hyundai (1503 Gadsden Hwy, Trussville, AL 35235); however, no error code was retrieved, and the vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 80.

Mileage: 80

I was driving on the freeway, at the speed limit, cruising along. Then all of a sudden, my vehicle starts to decelerate from 65 MPH and I push the gas, thinking I must have let up too much on the pedal. However, that only causes the RPM to drastically rise with NO change in my speed. I thankfully managed to maneuver from the far left lane to the freeway shoulder on the far right. The whole time, my speed was around 40 MPH and dropping drastically. Trying to safely navigate a slowing vehicle on a 65+ Texas freeway is an adrenaline-rush that I wouldn’t wish on anybody. I was severely panicking. I was almost hit by several vehicles in my maneuvering. I could have died last night. Once on the shoulder, I tried to start my car. I thought it may be a battery issue, but it turned on. It didn't start, though. The lights came on, as did all of the typical system/dash lights that usually indicate when a car’s engine hasn’t “turned over.” I used Bluelink to call for roadside assistance (since I’m only a little over 2 months into ownership) and waited. I was escorted off of the freeway to safety — thanks to a 3-car police escort AND free city tow trucks — and eventually picked up by Hyundai-serviced AAA. The latter then towed my vehicle to the dealership where I bought my Sonata. My car is currently being checked/inspected by my dealer (North Freeway Hyundai) and I only have gotten the following notice from Bluelink: "A possible condition with your Engine Control System has been detected with your 2023 SONATA on 02/22/2023 at 07:23 am CST. A full system check is recommended to be done soon." I checked and there are no open recalls (currently). Even more concerning, my car recently underwent complimentary maintenance, including an oil change, through my dealer (on February 13, 2023 - I have the receipt), was good on gas, and had no warning lights displaying. Until it stopped running — the time I tried to start it on the side of the road, the dash showed an “engine” light.