Complaint volume
358 consumer-submitted complaints are matched to this model year. Treat the count as a research signal, then read the actual summaries for repeated symptoms.
Complaint records
2018 Hyundai Sonata Complaints
358 consumer-submitted complaints on record for the 2018 Hyundai Sonata, grouped by component category.
358 Total complaints
18 Crash reports
12 Fire reports
9 Injury reports
Complaint data reflects consumer-submitted reports. A complaint is not proof
of a defect, recall, or manufacturer fault. Enriched severity fields come
from official bulk records when the complaint can be matched by ODI number.
Buyer interpretation
How to use these complaints before buying
Complaint records are most useful when they turn into inspection points, seller questions, and comparison checks against nearby model years.
Pattern to inspect
The most common categories are engine, unknown or other, electrical system,engine. Use those categories as a test-drive checklist instead of judging the vehicle from the total count alone.
Severity flags
Enriched records include 18 crash reports, 12 fire reports, 9 injury reports, and 1 fatality report. These fields come from complaint records and should be read in context.
Mileage clue
Mileage is available on 135 complaints, with an average reported failure mileage of 37,255 miles. Compare that with the mileage on the listing.
Questions to ask the seller
- Have you had any problems related to engine, unknown or other, electrical system,engine?
- Can I see recent maintenance and repair records?
- Has the vehicle ever been towed, involved in a crash, or repaired for the same issue twice?
- Can we also check the recall record for this 2018 Hyundai Sonata?
Used-car checklist
Use these complaints before the test drive.
Build a buyer checklist to turn these issues into questions and inspection points.
2018 Hyundai Sonata
Build buyer checklist Compare with other years Sends year, make, and model to pre-fill your checklist.
How severe are the 2018 Hyundai Sonata complaints?
18 Crash
12 Fire
9 Injury
1 Fatality
28 Towed
6 Medical attention
What are the most common 2018 Hyundai Sonata complaint categories?
ENGINE 113
UNKNOWN OR OTHER 32
ELECTRICAL SYSTEM,ENGINE 15
EXTERIOR LIGHTING 15
ENGINE AND ENGINE COOLING 11
STRUCTURE 11
ENGINE,FUEL/PROPULSION SYSTEM 8
POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM 8
ELECTRICAL SYSTEM 7
ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM 7
358 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| Aug 2025 | STRUCTURE | The paint has been chipping from the hood and top. | Crash: No Fire: No | Unknown |
| Aug 2025 | SERVICE BRAKES,FORWARD COLLISION AVOIDANCE | About a year and half ago, a lot of my engine trouble lights turned on while driving. It was sleeting at that time when the lights turned on and they're still on today. I paid to have the Hyundai dealer to check it out soon after the trouble lights first turned on. They diagnosed the problem as a faulty HECU. I would have had them replace this, but they estimated it would cost about $3800 to fix. This HECU malfunction is causing the following issues: ABS does not work, traction control does not work, forward collision prevention does not work, brake auto hold does not work, cruise control does not work probably because it can't auto brake any more. I've had some scary times driving and trying to stop when the roads have been wet or snowy. | Crash: No Fire: No | Unknown |
| Aug 2025 | ENGINE | Component or system that failed or malfunctioned: The 2.4L Theta II engine in my 2018 Hyundai Sonata is consuming an excessive and unsafe amount of engine oil—approximately 1 quart every 750–1000 miles. The engine has not seized or failed yet, but the oil consumption is abnormal and dangerous. The engine is available for inspection upon request. Safety risk: This oil consumption issue poses a significant safety risk. If the engine runs out of oil unexpectedly, it could lead to catastrophic engine failure and sudden loss of power while driving—potentially causing a serious accident. The lack of warning or engine light prior to dangerously low oil levels increases the risk. Reproduction/confirmation: The issue has been reproduced and documented by a certified Hyundai dealer through an oil consumption test. However, despite confirming the problem, Hyundai has refused to cover the repair. Inspection history: The vehicle has been inspected by a Hyundai dealership. No other independent agencies (e.g., insurance or police) have inspected it. Warning lamps or messages: No warning lamps appeared before the engine oil was found to be dangerously low. There were no check engine lights or oil pressure warnings prior to discovering the oil consumption issue. Other key information: Hyundai refuses to cover the repair due to the fact that I am not the original owner—even though the original Powertrain warranty would have covered the issue if I were. Hyundai arbitrarily reduces the powertrain warranty to 5 years/60,000 miles for secondary owners, despite the safety risks being identical regardless of ownership. Furthermore, this exact engine has been the subject of multiple lawsuits and class actions due to excessive oil consumption, connecting rod bearing failure, and engine seizure. Hyundai has acknowledged the defect in various settlements but continues to deny coverage for affected owners like me. | Crash: No Fire: No | Unknown |
| Aug 2025 | POWER TRAIN,ENGINE | Engine failure. Definitely a safety issue, check engine light flashing, limited engine power. Wouldn’t accelerate. Dealer inspected, there is a nationwide recall and class action lawsuits and they won’t replace even though it’s under warranty. False information saying maintenance neglect on my part. That is FALSE. Known failure and oil consumption. Rod bearing failure. | Crash: No Fire: No | Unknown |
| Aug 2025 | ENGINE | My car is consuming oil. Hyundai knows this is happening with the theta II engines. I was told to bring it in and do an oil consumption test which shows my car is consuming 1 qt oil every 406 miles but was denied help due to it being high Mileage and not under warranty. My car has now started misfiring due to cylinder 1 & 2 consuming oil. | Crash: No Fire: No | Unknown |
| Aug 2025 | ENGINE AND ENGINE COOLING | The contact owns a 2018 Hyundai Sonata. The contact stated that after starting the vehicle, the engine oil warning light illuminated intermittently. The contact pulled over to check the engine oil level and discovered that there was no oil in the engine. The vehicle was taken to Midas, and engine oil was added. The vehicle was later taken to another Midas, who found a crack in the engine oil pan. The vehicle was then taken to the dealer, who informed the contact that Midas had overtightened the oil pan during an oil change, so the warranty to repair the vehicle would not be honored. The vehicle was taken back to Midas, and the engine oil pan was replaced. The contact stated that he was currently in litigation with the dealer and the manufacturer. The manufacturer was made aware of the failure. The failure mileage was approximately 99,000. The VIN was unavailable. | Crash: No Fire: No | 99,000 |
| Aug 2025 | FUEL/PROPULSION SYSTEM | The fuel pump filter housing is the cause of the malfunction, it is available for inspection upon request. When I am driving I intermittently lose fuel delivery altogether and my car comes to a halt for a second until I press on the gas pedal to get the car going again, this puts myself and other people in danger if my car randomly stops while I am driving around others and causes crash risk. An independent service center ran a diagnostic and stated it was the fuel pump filter housing. It has not been inspected by the manufacturer, police, or insurance reps. But it has been inspected by the service center near me. An engine code was produced that pointed to the gas cap, but the gas cap was fine, which indicates fuel delivery issues. There was also shaking during acceleration prior to the incident happening. My VIN does not fall under the current extended warranty, but the issues are identical to the issues of the VINs that do fall under the extended warranty. | Crash: No Fire: No | Unknown |
| Aug 2025 | ENGINE,FUEL/PROPULSION SYSTEM | Urgent Complaint About Repeated Engine Issues on 2018 Hyundai Sonata (VIN: [XXX] ) Hello, I’m writing to file a formal complaint regarding a 2018 Hyundai Sonata, VIN [XXX] , currently financed and still owing $9,700, but the vehicle is no longer reliable or functional. For over a year, the car has had constant mechanical issues, primarily: •Spark plug failures within weeks of replacement •Repeated misfiring •Constant oil consumption — requiring oil refills every few days •No clear cause ever detected by diagnostic machines Despite replacing the top engine cover, spark plugs, filters, and performing other repairs, the car continues to break down and remains unsafe to drive. These issues began shortly after the 2-year warranty expired in 2023, and have escalated rapidly. This has caused severe financial hardship for my family, who still have to pay nearly $10,000 on a loan for a failing vehicle. I am requesting Hyundai to investigate whether this vehicle qualifies for: •An engine recall, hidden warranty, or class action settlement •A buyback or goodwill repair INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6) | Crash: No Fire: No | Unknown |
| Aug 2025 | ENGINE AND ENGINE COOLING,FUEL SYSTEM, GASOLINE,POWER TRAIN | The contact owned a 2018 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle sputtered, jerked, and lost motive power. The check engine warning light was illuminated. The vehicle was able to restart but made an abnormal ticking sound. The vehicle was taken to the dealer but was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 72,000. | Crash: No Fire: No | Unknown |
| Aug 2025 | ENGINE | Burning a lot of oil had car 11 months only drove a few month,now it’s a tapping sound dealer where i purchase will not help nor will Hyundai dealer 15,000$ out the window now I need to get the lifters fix I can’t take it. I feel like I’ve been had. Now I got to figure to fix the car out of pocket however o haven’t had the car 1 year yet 81,000 miles. | Crash: No Fire: No | Unknown |
| Aug 2025 | ELECTRICAL SYSTEM,ENGINE | 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 | Crash: No Fire: No | Unknown |
| Jul 2025 | EXTERIOR LIGHTING,UNKNOWN OR OTHER,ENGINE | Check engine light keeps coming on got it looked at , certain parts replaced & it’s still on something to do with the air filter | Crash: No Fire: No | Unknown |
| Jul 2025 | UNKNOWN OR OTHER | 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 | Crash: No Fire: No | Unknown |
| Jul 2025 | ENGINE | Engine burns oil about every 200, need to top off oil. Dealership and Hyundai corporate office will not take responsibility. | Crash: No Fire: No | Unknown |
| Jul 2025 | UNKNOWN OR OTHER,FORWARD COLLISION AVOIDANCE | When starting car warning lights came on for ABS, AEB, Cruise Control. Cruise control is locked out and not working due to these warnings. | Crash: No Fire: No | Unknown |
| Jul 2025 | ENGINE | Car keeps burning oil faster than normal which has resulted in car not starting multiple times even after a month old oil change. | Crash: No Fire: No | Unknown |
| Jul 2025 | ELECTRICAL SYSTEM | 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. | Crash: No Fire: Yes Towed | 125,000 |
| Jul 2025 | ENGINE | Crack oil pan | Crash: No Fire: No | Unknown |
| Jul 2025 | ENGINE | 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. | Crash: No Fire: Yes | Unknown |
| Jul 2025 | POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM | 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. | Crash: No Fire: No | Unknown |
| Jun 2025 | UNKNOWN OR OTHER,ENGINE | ⸻ 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. | Crash: No Fire: No | Unknown |
| Jun 2025 | ENGINE | 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 | Crash: No Fire: No | Unknown |
| Jun 2025 | LATCHES/LOCKS/LINKAGES | 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. | Crash: No Fire: No | Unknown |
| Jun 2025 | POWER TRAIN,ENGINE | 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 | Crash: No Fire: No | Unknown |
| Jun 2025 | STEERING,ELECTRICAL SYSTEM,VEHICLE SPEED CONTROL | 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. | Crash: No Fire: No | Unknown |