Complaint volume
364 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
364 consumer-submitted complaints on record for the 2018 Hyundai Sonata, grouped by component category.
364 Total complaints
18 Crash reports
13 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. 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, 13 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 139 complaints, with an average reported failure mileage of 37,794 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?
- 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
13 Fire
9 Injury
1 Fatality
28 Towed
6 Medical attention
What are the most common 2018 Hyundai Sonata complaint categories?
ENGINE 147
UNKNOWN OR OTHER 38
ELECTRICAL SYSTEM 19
EXTERIOR LIGHTING 16
POWER TRAIN 15
ENGINE AND ENGINE COOLING 11
STRUCTURE 11
SERVICE BRAKES 9
FUEL/PROPULSION SYSTEM 8
LATCHES/LOCKS/LINKAGES 6
364 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| Jul 2025 | POWER TRAIN | 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 | 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 | 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 |
| Jun 2025 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Jun 2025 | FUEL/PROPULSION SYSTEM | 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. | Crash: No Fire: No | Unknown |
| May 2025 | FUEL/PROPULSION SYSTEM | 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. | Crash: No Fire: No | Unknown |
| May 2025 | SERVICE BRAKES, HYDRAULIC | 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. | Crash: No Fire: No | 40,000 |
| May 2025 | ENGINE | CAR STALLS; ENGINE IMPAIRED; OIL CONSUMPTION PROBLEM | Crash: No Fire: No | Unknown |
| May 2025 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| May 2025 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| May 2025 | ENGINE | I have to put a quart of oil in every week. It burns oil. | Crash: No Fire: No | Unknown |
| May 2025 | UNKNOWN OR OTHER | Panoramic sunroof came loose on highway and bent up 90 degrees making vehicle undrivable. | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE | 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. | Crash: No Fire: No | Unknown |
| Apr 2025 | STEERING,POWER TRAIN,ENGINE | The engine stalls when driving, loses power, hard time to start. It uses an extensive amount of oil. Losing power/stalling can result in accident or fire in my engine. Yes check engine light came on said it was coils/plugs changed them 2xs already. Took it to a mechanic was told there’s a recall on engine it’s a valve that is not getting air through that can potentially case a Fire in my engine. | Crash: No Fire: No | Unknown |
| Apr 2025 | POWER TRAIN | The car went into limp mode they have problems with the knock sensor and that is what it threw to the computer and I changed the sensor and went away and now limp mode again and computer says basically the same thing there is a software update and the engines are failing | Crash: No Fire: No | Unknown |
| Apr 2025 | ENGINE AND ENGINE COOLING | The contact owns a 2018 Hyundai Sonata. The contact stated that the vehicle needed multiple attempts in order to start. The contact stated that once the vehicle was started, she noticed that the low engine oil pressure light was illuminated. The vehicle was taken to a local dealer, where it was determined that an oil consumption test needed to be completed. The vehicle was not repaired. The contact had stated that prior to the oil test being recommended, she had observed that the vehicle was consuming approximately five quarts of oil per 2,000 miles. The manufacturer was notified of the failure. The failure mileage was approximately 57,000. | Crash: No Fire: No | 57,000 |
| Mar 2025 | ENGINE | My 2018 Hyundai Sonata (approx. 60,000 miles) began consuming excessive oil, and the engine started smoking while driving. My wife barely made it to the dealership — the car was unsafe, struggled to stay running, and visibly smoked from under the hood. Hyundai acknowledged the oil issue but refused to cover engine replacement. Instead, they approved a one-time combustion chamber cleaning and requested we drive the car 1,000 miles to "see if it gets better." This is a major safety concern. The vehicle is part of a group of Hyundai models known to have defective Theta II engines that have led to engine failure, fire risk, and recalls. This issue is widespread, and Hyundai is not taking proper responsibility for defective engines in cars like mine. | Crash: No Fire: No | Unknown |
| Mar 2025 | ENGINE | The engine is burning through oil at a rapid rate. I probably get 2,000 - 2,500 miles before it needs a complete refill and the problem is getting worse. I was not due for an oil change recently around 2,500 miles and my engine started shaking, took it to the shop and the oil was gone without the oil light going off. This resulted in me needing to replace spark plugs and all engine coils. The repair shop recommended I sell my car because of the amount of Hyundai's he sees with this issue. | Crash: No Fire: No | Unknown |
| Mar 2025 | ENGINE | The contact owns a 2018 Hyundai Sonata. The contact stated that the oil pressure was prematurely lower. The contact stated that while performing the oil change as an independent mechanic, the contact noticed that there was a significant amount of oil in the oil catcher, and the oil pan was fractured. The vehicle was taken to the dealer, where the contact was informed that the oil pan replacement was not covered under warranty. The vehicle was not repaired. The contact related the failure to NHTSA Action Number: DP22003 (Engine). The manufacturer was notified of the failure and a case was filed. The failure mileage was approximately 64,400. | Crash: No Fire: No | 64,400 |
| Mar 2025 | STRUCTURE:BODY | The engine burns oil, I have to get spark plugs every two months, and put oil in it almost every week. The check engine light is now flashing and is throwing more sensors. The paint on this car is also all peeling off. | Crash: No Fire: No | Unknown |
| Mar 2025 | LANE DEPARTURE: BLIND SPOT DETECTION | BSD system stopped working one day along with the Rear Cross Traffic Alert.The button which operates system does not come and system does not work. Warning lamp lit on instrument panel and said" check B SD system" meaning the whole system doesn't work. Took to my local shop and they couldn't repair as they stated the system is a proprietary system the had no software. service bulletin #19-BE-009H was issued in 5-19 by Hyundai for this issue with car. So there is a know problem | Crash: No Fire: No | Unknown |
| Mar 2025 | POWER TRAIN | I was going 80 mph on the interstate and suddenly my car went into limp mode and shooked really hard and dropped to 60 mph. I had to swerve to go onto the side of the road. The car behind me almost rammed into me. I contacted hampton hyundai for days to schedule an appt. I finally was able to drop off my vehicle to them but now they are telling me they have to do an oil consumption test but my car is in limp mode and it shakes when I drive it. The car is dangerous and they are trying to charge me $500 for a fuel pump replacement ( which I have a warranty of but they notified me that does not count but it matches exactly the possible reason). As you can see in the documents, they did not note that my fuel pump was broken. They just asked if I wanted to pay it so they can get started. I get normal oil changes done. They haven't even done a rod bearing test but just looked at the knock sensor and was telling me that they wanted to charge me to get that changed. | Crash: No Fire: No | Unknown |