2018 Hyundai Sonata
Problems, recalls and owner-reported issues
Engine is the leading concern among 373 owner complaints filed for this model year. This is the 12th highest complaint count among 26 Sonata model years with reports.
Of the 2018 reports, 18 involved a crash and 13 involved a fire. 20 people were injured and 1 person died.
What owners report most often
Recalls and investigations
Latches/locks/linkages, trunk lid, latchAug 6, 2021
Hyundai Motor America (Hyundai) is recalling certain 2017-2018 Sonata, 2016-2018 Sonata Hybrid, 2018-2020 Accent, and 2016-2017 Azera vehicles. The trunk latch may become damaged, preventing the opening of the trunk from the inside. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 401, "Internal Trunk Release."
A person inside the trunk compartment may become trapped, increasing their risk of injury.
Dealers will replace the trunk latch base, free of charge. Owner notification letters were mailed December 4, 2021. Owners may contact Hyundai customer service at 1-855-371-9460. Hyundai's number for this recall is 208.
Campaign 21V619000 on NHTSA.gov
Representative owner complaints
373 reports, newest first.
Electrical system, Engine, Aug 3, 2025
car turned off at light all lights work and turns on engine won’t roll over the battery and alternator and starter are all good
Exterior lighting, Other or unspecified, Engine, Jul 31, 2025
Check engine light keeps coming on got it looked at , certain parts replaced & it’s still on something to do with the air filter
Other or unspecified, Jul 31, 2025
My starter failed after 35,683 miles leaving me stranded in a parking lot at night. The life expectancy for a starter is between 100,000and 150,000 miles. Hyundai replaced the part at a cost of $1,139 which is way above what it normally costs to replace a starter. The starter is at the dealership and is not available for inspection. Being stranded in a parking lot made me very uncomfortable and what if the starter had failed in a bad section of town. The problem was confirmed by a Hyundai dealership who replaced the part after I had my vehicle towed to their service department. The only ones who inspected the vehicle was a mechanic at the dealership. There wer no warning lamps or messages, but I did notice the car did not start on the first try before the starter failed. 07/29/2025
Engine, Jul 28, 2025
Engine burns oil about every 200, need to top off oil. Dealership and Hyundai corporate office will not take responsibility.
Other or unspecified, Forward collision avoidance, Jul 15, 2025
When starting car warning lights came on for ABS, AEB, Cruise Control. Cruise control is locked out and not working due to these warnings.
Engine, Jul 11, 2025
Car keeps burning oil faster than normal which has resulted in car not starting multiple times even after a month old oil change.
Engine, Jul 8, 2025
Crack oil pan
Electrical system, Jul 8, 2025, fire
The contact owned a 2018 Hyundai Sonata. The contact stated that upon her daughter reaching her destination, she observed brown smoke emanating from the engine compartment. Within a short while, the vehicle became completely engulfed in flames, prompting a bystander to attempt to extinguish the fire with a fire extinguisher, but was unsuccessful. Local emergency services arrived and were able to extinguish the flames. A fire report was filed, and it was indicated that the fire may have been electrical, but an exact cause had not been determined. A police report was filed, and no injuries were reported. The vehicle was towed to a tow yard and deemed a total loss by the contact's insurance provider. The manufacturer was not notified of the failure. The failure mileage was 125,000.
Engine, Jul 7, 2025, fire
My 2018 Hyundai Sonata caught fire unexpectedly while parked. The engine suddenly began smoking, then the vehicle ignited and was severely damaged. I am still financing the vehicle through Capital One. After researching, I discovered that my vehicle’s engine is part of a known Hyundai recall due to fire risk (Theta II engine defect). I had no prior warning or engine-related issues that would have predicted this. I strongly believe the fire was caused by a manufacturing defect, and I’m requesting that NHTSA investigate Hyundai’s handling of this issue and ensure victims like myself are compensated — even if not physically injured. I can provide photos, a fire report, and additional documentation if needed. Please let me know the next steps or if I qualify for any related recall recovery programs.
Power train, Engine, Fuel/propulsion system, Jul 4, 2025
The engine shuts off, doesn’t start, check engine light flashing, losses power, jerks while driving it, i will get it up yo speed then will shut off or won’t move.
Other or unspecified, Engine, Jun 27, 2025
⸻ In early 2024, I brought my vehicle to a Hyundai dealership due to rapid oil loss. I reported having to refill the oil weekly and suspected a leak. They diagnosed a cracked oil pan, claimed to fix it, and returned the car. However, immediately after, the car continued burning oil at an alarming rate. I was forced to buy and add oil every single week, spending hundreds of dollars to maintain drivability. Shortly after the repair, I began experiencing erratic dashboard warnings. The check engine light would frequently come on and off. The oil lamp illuminated every few days. These symptoms were persistent, not isolated incidents. Despite reporting the issue again, I was told the oil burning was “normal” for Hyundai engines and nothing to worry about. That response put my safety and my child’s safety at risk, as I was unknowingly driving a vehicle with worsening engine damage. Eventually, the car stopped running entirely. It was no longer drivable or safe. I took it to a licensed independent mechanic who confirmed there were multiple ongoing oil leaks and extensive engine damage. The issues I originally reported were never properly fixed, and it’s now clear the dealership failed to address the root cause of the oil consumption problem. I also noticed unusual spikes in the odometer after their repair, despite working from home and barely driving. This added further concern that the vehicle’s internal systems may have been compromised or malfunctioning. I believe Hyundai’s failure to act on clear warning signs directly led to this total engine failure and a serious safety risk.
Engine, Jun 26, 2025
I purchased this vehicle from the seller the vehicle then immediately gave me engine issues. I contacted the Hyundai dealership which the vehicle got recent services with. They told me that the claim was denied even though the car has an extended warranty until 120,000 miles and the vehicle has less than that due to a regular oil changes they recommended me call Hyundai corporate to see if they can help out. I then contacted Hyundai corporate, and they essentially stated the same thing saying that the vehicle did not qualify for the extended warranty due to outside factors which were the irregular oil changes. I let them know that the vehicle did not get regular oil changes and I provided them with a Carfax report they then told me that in order for the card to be classified as getting regular oil changes and maintenance is every 5000 miles and this vehicle got most of his oil changes done 10,000 and 15,000 miles now I am stuck with a vehicle with a engine that is knocking even though it should still be under warranty
Latches/locks/linkages, Jun 26, 2025
See attached document for complaint. Please let me know how quickly the service parts for these two recalls are physically located in your shop and how soon the required recalls will be performed. I have been getting periodic recall notices for years and have yet to obtain the satisfaction of an adequate local response from your service department. I can recall three instances when I was told the parts were ready, only to leam, upon arrival, they were not. The last incident was on May 27"', when I was told the parts were ready and I could have the recall performed on May 30'". Another huge disappointment occurred when I was told the parts were not available. That is not the way to run a governmental required recall program.
Power train, Engine, Jun 11, 2025
The car in recent months has twice lost power and been rendered in operable on the side of the road until it could be limped home. I had the car serviced last year for a recall of a fuel filter gasket and at that time I was informed that I also had an update done for a (k knock?) sensor prior done on the car before purchase. I inquired about what that was, and they told me at the time it was for an engine recall because that particular engine I have is known to have rod bearing failure and consume oil without any trace of where it goes and piston rattle. I told the gentleman after my fuel gasket was taken care of that I would like to look into that because I have the symptoms and would like to know. At that point in time, I was told that I may have to do an oil test to see if the car loses oil. I said well can we do that and he told me it's $300 out of pocket. I asked on average before anything ever done by Hyundai, how many times do people have to do this? He said 4 to 6 in his experience. I told him I did not have the money, but I will keep an eye on the car. Everything's been fine for six months a few months ago Randomly driving to work the car shut down on me. We got the car home and my fiancé did an oil change and new spark plugs and the car worked fine. June 9th 2025 on my way to work the issue happened again in the middle of traffic. I called my fiancé and we got the car home. He performed another oil change and spark plug replacement and took pictures this time because the spark plugs are gunked up. The car now runs again. He called Hyundai of America on my behalf to just ask them if they could set up the test to see if the car was failing and they told him that they were all independent Hyundai and he would have to pay the test fees. He told them in a formal email that he doesn't believe under the federal recall He is responsible for that and they answered back that he may be reimbursed. We are contacting you because we were advised to on the issue
Steering, Electrical system, Vehicle speed control, Jun 10, 2025
On 05/27/2025, my rear back-up camera started to malfunction. Last week my dash started to malfunction electronically. When I would start my vehicle, all of the lights would start to turn on and stay on on my dash. My speedometer would not move while I was driving, so I could not see how fast I was going. I believe this is a severe safety issue for myself as well as others. The tachometer would jump up and down and would not function correctly. My dash stated that I had low tire pressure, that I was having problems with my traction control, that my BSD system was not working, that my ABS was not working, that my emergency brake was on even though it was not. It also stated that I did have functioning air bags, which is a severe safety hazard in the chance that I could've gotten into a wreck and they might not have worked. It also stated that I was not in Drive even though I clearly was. It also stated that I had no power steering while I was driving, before the light would turn off and I could properly steer again. This is a severe safety issue that could put me at risk. Finally, my check engine light turned on and stayed on. Yesterday on 06/09/2025 I was able to take it a vehicle maintenance shop so they could run a full diagnostic test. They discovered that I did not have power steering even though there was fluid due to the electrical problems with my dash. They also discovered the C-CAN buss was off and that my vehicle was losing communications with the TCM and HVAC. It was discovered that this was due to my rear view back-up camera malfunctioning, causing the C-CAN network to short out. They had to unplug my rear back-up camera to return everything to normal. I have found on hyundai recall forms that other years of hyundai models had similar problems and I believe that 2018 hyundai sonatas are also having the same problem. I wanted it to be made aware because online, people have stated they are having the same issues. Attached gif that shows part of problem.
Engine, Jun 8, 2025
Failure of engine oil pan. - Hairline crack in oil pan caused enough oil to leak out threatening engine failure. Problem caught in time to avert failure. - Oil pan will be available if requested. - Personal safety not at risk but could have been if failure occurred while driving. - Problem was discovered and confirmed at by independent service center. - No inspection has been done by others. - YouTube and internet search shows same problem. - No warning warning signs or messages. - Problem not covered by manufactures warranty for second owner.
Other or unspecified, Engine, Fuel/propulsion system, Jun 5, 2025
Multiple critical mechanical and safety issues have occurred with my 2018 Hyundai Sonata Sport. The vehicle has experienced persistent engine misfire, a severe oil leak, emissions system failure, and extensive paint deterioration. A certified technician confirmed an active oil pan leak with no dashboard warning lights, posing a fire and stalling hazard. To prevent further damage, I replaced the entire oil pan and spark plugs at a personal cost of approximately $800 at Firestone Complete Auto Care. The check engine light revealed diagnostic code P0420 – Catalyst System Efficiency Below Threshold (Bank 1). An O’Reilly emissions scan confirmed the catalytic converter failure, and emissions status was marked “RED.” The vehicle will not pass an OBD-based emissions test. At 149,219 miles, Hyundai refused warranty coverage due to mileage. A certified Hyundai dealership quoted $3,722 to replace both the catalytic converter and valve cover gasket, which remains unaffordable and unrepaired. In addition, the factory-applied white paint began peeling severely from the hood and roof. Although Hyundai issued a warranty extension for this known defect, the dealership refused to repaint the hood, citing a minor dent — even though the peeling is clearly unrelated. The exposed metal has started to rust, risking structural deterioration. All concerns have been evaluated by certified Hyundai service and independent professionals. These combined mechanical, emissions, and exterior failures raise serious safety and durability concerns. I am filing this report to document manufacturer-related defects that may affect other owners of this model and year.
Engine, Fuel/propulsion system, May 24, 2025
Burns oil fast. 900 miles from an oil change the car oil stick was empty. There are no signs of oil leaking. Every 1000 miles you have to place oil back into it. I’m not the only one complains of this issue. I was reading on Reddit and it’s thousands of people having the same issue.
Service brakes, Hydraulic, May 21, 2025
The contact owns a 2018 Hyundai Sonata. The contact stated that upon starting the vehicle, the ABS warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed and determined that the ABS module had failed. The vehicle was not repaired. The dealer was notified of the failure. The manufacturer was not notified of the failure. The failure mileage was approximately 40,000.
Engine, May 14, 2025
CAR STALLS; ENGINE IMPAIRED; OIL CONSUMPTION PROBLEM
Engine, May 13, 2025
I have had to have the starter replaced twice, I have had to change the spark plugs 5 times. I have to put oil in it about every 3 weeks. White smoke comes out of the muffler. The mechanic said I need to have an oil consumption test, which Hyundai will not covet.
Engine, May 12, 2025
I have a 2018 sonata. It has thrown a p1326 code. There is a TSB for that code where the dealership will Check to see if the engine will Be replaced. My car passed that test meaning no engine replacement. My car has 107,000 miles on it and has had regular maintenance. In between oil changes I’m having to add oil. I’m spent hundreds on engine oil since taking owenship of the car. There is obviously an issue with the engine since there is a TSB. Yes my car passed”passed the test this time” (I’m having to pay $600 to replace the knock sensor). I feel like I’m driving a ticking time bomb and money pit. I feel as though Hyundai should handle this known issue. I need help.
Other or unspecified, Engine, May 8, 2025
I have to put a quart of oil in every week. It burns oil.
Other or unspecified, May 7, 2025
Panoramic sunroof came loose on highway and bent up 90 degrees making vehicle undrivable.
Engine, Apr 29, 2025
This engine consumes oil rapidly to the point i have to add quarts of it constantly . This results in the spark plugs deteriorating at a rapid rate and the coil packs as well. The car only has 75,000 miles but the problems began to start around 69,000 miles because of these issues and the engine and burning oil because of the rings and pressure it begins to shake rapidly and sputter and stall out.