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.
Engine, Mar 15, 2026
2018 Hyundai Sonata 2.4L Theta II engine experiencing severe oil consumption and loss of oil pressure. Oil pressure warning light actively blinking and dipstick completely dry. This is consistent with the known Theta II engine defect subject to prior NHTSA investigations and class action settlements. Mission Hills Hyundai documented low oil concern in service notes during December 2025 visit but failed to take any action and returned the vehicle without repair. Hyundai Consumer Affairs has been unresponsive and provided conflicting information regarding recall completion on this vehicle. This is a serious safety defect that puts the driver at risk of engine failure while operating the vehicle.
Power train, Electrical system, Engine, Mar 15, 2026, crash
The vehicle had safety and mechanical problems shortly after purchase, even with low mileage. The issues included warning lights, abnormal noises, repeated mechanical failures, and poor performance that affected the safe operation of the vehicle. These problems started early and continued over time despite repairs and maintenance. Before the incident, the vehicle showed signs of malfunction, including instability while driving and loss of normal performance. These symptoms created an unsafe driving condition and increased the risk of a crash. I believe the vehicle had defects from the beginning that affected safety. The failure contributed to the accident that occurred while driving on the highway, putting my life and my family at risk.
Engine, Mar 9, 2026
Excessive Oil Burning and Oil Consumption. Oil turns black abnormally quickly (within the first 500-1000 miles) even though recommended Full-Synthetic Oil is used. Engine has intermittent rough idle once engine is warm. Occasionally engine experiences "near-stall" and "misfire event", causing the battery light to flash on dashboard. >>>Oil consumption rate is approximately 3-4 quarts per 1,000 miles<<< ***Maintenance completed since purchase*** Coolant Flush - Replaced PCV Valve (NEW) - Replaced Valve cover Gasket + Oil Pan / Oil Pan Gasket (recommended by dealer) (NEW) - Replaced Spark Plugs (recommended by dealer) (NEW) - Replaced Battery (NEW) - Replaced Alternator (NEW) - Replaced both engine accessory belts (NEW) - Replaced 150A main fuse (located on positive battery terminal) (NEW) - Used Hyundai brand oil filters - Used Chevron/Techron Complete Fuel system cleaner twice, between and at oil change (as recommended by "Twin City Hyundai" dealer in Alcoa, TN) ***Had dealership inspect it for approval of known Federal Recall on GDI Engines for excessive oil consumption / engine seizing issues; dealership claimed it did not pass re-call approval*** SYMPTOMS STILL PERSIST Mileage is now approx. 80K
Engine, Feb 20, 2026
The component involved is the engine (2.4L Theta II gasoline engine) in my 2018 Hyundai Sonata. The malfunction involves excessive internal engine oil consumption between oil changes. The vehicle consumes oil at an abnormal rate, requiring frequent top-offs to prevent low oil levels. The vehicle is available for inspection upon request. This condition creates a safety risk because excessive oil consumption can lead to critically low oil levels, engine seizure, sudden engine stall, or loss of propulsion while driving. A sudden engine stall or loss of power while operating at highway speeds could increase the risk of a crash. The problem has been inspected and documented by an authorized Hyundai dealership. During service, the dealership recorded that the customer reported oil burning between oil changes and noted evidence of engine oil consumption. No permanent repair has been performed. The issue remains unresolved. Hyundai Motor America has not physically inspected the vehicle directly but has reviewed the case through customer care. The manufacturer has required additional diagnostic testing at the owner’s expense as a condition of further evaluation and declined to authorize testing at no cost or provide assurance of reimbursement. No crash, fire, or injury has occurred to date. The vehicle has not been inspected by police or insurance representatives. There were no warning lamps illuminated at the time the oil consumption was first observed. The condition was first noticed when oil levels were found to be significantly low between scheduled oil changes. The issue has been ongoing and progressive. Given the known history of engine-related issues involving Hyundai Theta II engines, I am submitting this complaint due to concerns that continued oil consumption may result in engine failure, sudden stall, or loss of propulsion while driving, creating a potential safety hazard. The vehicle remains in service but the condition has not been corrected.
Engine, Feb 19, 2026
The oil pan is starting to crack, a small drip is now happening but dealership says it could spilt and cause the engine to seize while driving. The pan looks very flimsy compared to my Ford and Toyota.
Electrical system, Engine, Feb 14, 2026
To Whom It May Concern, My name is [XXX] , and I am formally escalating serious ongoing issues with my 2018 Hyundai Sonata. Despite repeated attempts to resolve these concerns through the dealership, my vehicle continues to experience excessive oil consumption, engine failures, and additional mechanical issues, all while under warranty. I am now seeking immediate corporate intervention. Timeline of Events and Mismanagement: •2024(~62000 miles): First reported oil leak and excessive oil consumption. Directed to complete multiple 1,000-mile oil consumption tests. I complied fully. •2024: Repeatedly redirected between service advisors, received conflicting instructions, misleading guidance, and poor communication. No effective resolution was provided. •2025: Completed extensive additional diagnostic testing as requested. Despite full compliance, no clear corrective action was taken. •2024–Present: Vehicle brought to Hyundai on US 19 in New Port Richey approximately 13–15 times for engine-related concerns. Each visit demonstrated neglect, miscommunication, and failure to properly address documented issues. •February 11, 2026: After proper diagnostics, vehicle found to have two additional oil leaks, including a head gasket and valve cover requiring replacement, with total estimated repair costs exceeding $3,000. I was advised I must repeat all testing already completed in 2024 before final determination. •Vehicle is currently at 71,332 miles. Impact: •Delays and repeated unnecessary testing pushed my vehicle beyond warranty limits. •Mismanagement caused significant financial burden, emotional stress, and frustration. •If initial oil consumption issues had been properly addressed under warranty, the current extensive engine failures could likely have been avoided. Immediate Requests: 1Full review of my complete service and diagnostic history. 2Warranty or goodwill coverage for all necessary engine repairs, including head gasket and valve cover INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Engine, Feb 5, 2026
While driving the vehicle, I repeatedly must check and put oil in. (On average once per week) I took the car to an auto shop where I was told that the engine was bad and I must get a new one. I kept driving, putting oil in as needed, then the car in the middle of driving started to shudder and the check engine light came on. I parked the car and haven't driven it since
Power train, Electrical system, Engine, Jan 29, 2026, fire
Unknown what system failed. The vehicle is at an impound lot and can be inspected on request. Police and fire department were on the scene. Police did provide a report # , and fire department provided a fire rescue case number. Safety of driver was put at risk due to the fire and potential for burning or even death. Other drivers could have been at risk if traffic had not allowed for quick movement to side of the road. No warning lamps had been on prior to the drive and none prior to fire. First indication was a burning smell while driving. As pulling over, another driver honked to alert to fire he could see from rear of ca,. before I noticed the flames. Upon getting out of car first flames I saw appeared to be coming from under passenger side of car. The fire department arrived about 15 minutes after pulling to side of the road. The car was fully engulfed in flames. They then extinguished the fire. Police saw vehicle and insurance will examine. Apparently this is a known issue in Hyundai of which this vehicle had no open recalls pertaining to such.
Air bags, Jan 11, 2026
The three airbags in the car (on the driver's weel, driver's knee, and the passenger's side) deployed while driving on a normal street at a speed of 50 miles/hour. This is an unexpected behavior of a car at a normal speed. I need help to fix this car and know what is the reason this happened.
Engine and engine cooling, Jan 9, 2026
The contact owns a 2018 Hyundai Sonata. The contact stated that while driving approximately 60 MPH, the vehicle started to vibrate roughly. The contact felt the vibration in the steering wheel. The check engine warning light was illuminated. The contact slowed down and pulled off the roadway. The contact turned off and restarted the vehicle and was able to shift to drive(D); however, the vehicle was hesitating and failed to accelerate as needed. The contact drove the vehicle to an independent mechanic at speeds no greater than 40 MPH. The mechanic scanned the vehicle and retrieved codes for a misfire in the engine. The mechanic advised the contact to take the vehicle to a dealer for assistance. The vehicle was towed to the local dealer. The vehicle was not yet diagnosed or repaired. The manufacturer was informed of the failure. The contact requested an engine replacement that was denied by the manufacturer. The failure mileage was approximately 138,000.
Engine, Jan 6, 2026
Engine oil consumption issues. My 2018 Hyundai Elantra falls within the dates of this issue. I had an oil consumption issue done and the dealership claimed it passed. I have to put oil in my car every 3 weeks and change spark plugs at the same time because of engine leaking oil in to them. My engine light is always on, knocking and pinging sound, poor performance issues, and blue smoke coming out of tail pipe. I have stuck on the side of the highway several times and have misses work because of the ongoing issues with the engine. How can a oil consumption issue pass and i have all these issues. I have spent several hundreds of dollars on oil, spark plugs, frequent oil changes and tows. There was only 85,000 miles when I started to notice the problem and had only owned it for 6 months.
Electrical system, Other or unspecified, Dec 28, 2025
Intermittent no-crank, no-start condition. Dash lights illuminate, push-button start produces no response. Brake pedal applied. Vehicle becomes immobilized without warning. I’ve been stranded on multiple occasions. Unable to commute to work, or home. Most recently on December 19,2025 the car completely shut off while driving on the highway.
Engine and engine cooling, Dec 22, 2025
The contact owns a 2018 Hyundai Sonata. The contact stated that while receiving an oil change, the technician advised that the oil level was very low. The contact stated that the low oil warning was intermittently illuminated. The contact was advised to take the vehicle to a dealer to be diagnosed. The contact had taken the vehicle to a local dealer, where an oil consumption test was performed. The contact was advised that the vehicle was operating normally. The contact stated that the low oil warning light was illuminated again. The vehicle was taken back to the same dealer, and the oil level was topped off; another oil consumption test was suggested. The contact researched online and related the failure to a known issue of oil consumption that could lead to engine failure. The contact called the manufacturer and asked about an engine replacement because the vehicle was still under warranty. The manufacturer informed the contact that a combustion cleaning had to be performed to determine if the engine needed to be replaced. The contact stated that the vehicle was taken back to the same dealer who performed the combustion cleaning; however, the excessive oil consumption remained, and there was evidence of burned oil coming from the exhaust pipe. The contact called the dealer and was advised that another oil consumption test and combustion cleaning were needed. The vehicle was not repaired. The failure mileage was 103,235.
Other or unspecified, Dec 21, 2025
Excessive oil consumption. I am routinely getting notifications of low oil about 1,000 miles before the oil change is due. When I bring it in for an oil change it is nearly empty. No signs of leaks anywhere.
Air bags, Dec 17, 2025, crash
I am Detective [XXX] #XXX with Austin Police Department Vehicular Homicide Unit and I worked a fatal crash [XXX]. The damage to the vehicle two vehicle should not have caused a death. The airbag became detached from the steering wheel and impaled into the drivers chest. I do have pictures but they are crime scene pictures and pictures of the decedent so I am not attaching them but if someone contacts me I can arrange that. I do not know the speed but I am going to image the module next week. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Power train, Engine, Fuel/propulsion system, Dec 16, 2025
While driving on the highway, my 2018 Hyundai Sonata experienced sudden loss of engine power and became undrivable. The failure occurred without warning at approximately 86,500 miles. At the time of the incident, there were two children in the vehicle, and the breakdown occurred at night in cold temperatures (approximately 20°F). An authorized Hyundai dealership later diagnosed zero compression in cylinder 3 and confirmed a cracked piston, recommending full engine replacement. The sudden loss of power while driving created a safety risk due to traffic conditions and environmental exposure.
Engine and engine cooling, Dec 5, 2025
The contact owns a 2018 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the low oil warning light illuminated. The vehicle was taken to the dealer, but was not diagnosed or repaired. The dealer advised the contact to have an oil change performed and then return the vehicle after 1,000 miles of driving. The contact stated that after returning the vehicle to the dealer, the vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 99,000.
Engine, Dec 2, 2025
I bought this vehicle as a certified pre-owned from a Hyundai dealership on 09/10/2022 with 32,677 miles. Around 85,000 miles, it began burning an excessive amount of oil—about two quarts per month. Now, with approximately 101,000 miles, it still burns two quarts weekly, oil is being expelled from the muffler, and the exhaust has started to glow red. I have tried contacting Hyundai but have not received any response.
Engine, Nov 25, 2025
Car started misfiring while driving and engine light came on. It kept losing power but I was able to pull off highway. This put myself and others in danger because speed was significantly reduced suddenly. Dealer said problem was due to oil leaking on spark plugs. The car had been using excessive oil. Dealer said this is known issue but I had to pay for any repairs since I was the second owner. Hyundai still pays for the original owner to get an oil consumption cleaning, but recently stopped paying for secondary owners. If the oil consumption cleaning does not work, then the next step is to replace engine, paid by customer if Hyundai refuses. Mileage on car is 75,769.
Engine, Fuel/propulsion system, Nov 22, 2025
I am submitting a formal complaint regarding ongoing and severe engine issues with my 2018 Hyundai Sonata SE. Despite proper maintenance, the vehicle has developed extreme oil consumption and misfire problems that have made the car unreliable, unsafe, and financially burdensome. Beginning around 118,000 miles, the vehicle started consuming oil so rapidly that I was forced to completely replace the oil every 1–2 weeks because it would run dangerously low or nearly empty. This level of oil loss is not normal, acceptable, or sustainable. I have detailed documentation, receipts, mileage logs, and maintenance history supporting this. In addition to oil consumption, the vehicle has repeatedly misfired, produced diagnostic trouble codes, and fouled spark plugs with oil. I have been forced to replace spark plugs approximately every two weeks, which is clearly abnormal for any modern vehicle. On multiple occasions, the vehicle has experienced violent knocking noises, severe loss of power, hesitation during acceleration, and near-stalling. One incident was so loud and aggressive that it felt like the engine was going to come out of the hood. These symptoms pose a serious safety risk while driving. I brought the car to a Hyundai dealership at approximately 118,000 miles for an oil-consumption test. The vehicle failed that test, clearly confirming excessive oil consumption. Despite this, Hyundai refused to provide repair, internal engine cleaning, or engine replacement, claiming the vehicle was already over 100,000 miles I have maintained this vehicle responsibly and have documentation of regular oil changes, spark-plug replacements, inspections, and diagnostic reports. Despite my efforts, the issue continues to worsen, and the vehicle remains unsafe and unreliable. This ongoing problem has caused significant financial strain, emotional stress, lost time, and fear of engine failure while driving. Based on countless similar complaints from other Hyundai owners, this appear
Engine and engine cooling, Nov 14, 2025
See attached document for complaint.
Engine, Nov 10, 2025
My 2018 Hyundai Sonata’s oil light flashed briefly while driving, so I checked the oil level and found the dipstick completely dry. The car has been maintained regularly and was still about 1,000 miles away from its next scheduled oil change. There are no visible leaks, and the engine is not smoking. I had to immediately add oil to prevent engine damage. This appears to be a case of excessive oil consumption, which I have since learned is common in Hyundai Sonatas with this engine. I am very concerned that low oil pressure could cause engine failure or sudden loss of power while driving, creating a serious safety hazard. I request that NHTSA investigate this issue for 2018 Sonatas, as many owners are reporting similar experiences, and Hyundai has issued a Technical Service Bulletin (TSB 23-EM-008H) about excessive oil consumption but no recall.
Steering, Suspension, Power train, Nov 6, 2025
During multiple dealership visits in 2025, my 2018 Hyundai Sonata Limited 2.0T was repeatedly returned in unsafe condition. Southern Hyundai installed both front CV axles and torqued them incorrectly. The right axle was later confirmed under-torqued by about 50 ft-lbs, and the left axle was later found over-torqued 40ft-lbs Priority Hyundai later identified and corrected the under-torqued right axle, which briefly improved symptoms but did not resolve the underlying issue. When I returned for a follow-up on October 29, 2025, for a documentation-only appointment due to an active corporate case, the dealer ignored my instructions and altered evidence by loosening and re-torquing the left axle nut without consent. They recorded the torque at 250 ft-lbs in the repair order but failed to capture the required photos or before/after readings and referenced the wrong vehicle’s torque specification (Hyundai Elantra) in the documentation. Since then, the vehicle has continued to show steering pull, vibration, and instability at speed. Several visits showed only 0–3 miles of verification driving after safety-critical repairs involving brakes, suspension, and driveline components. Aftermarket parts were installed when OEM parts were promised, and uneven tire wear developed quickly. Safety risks include wheel-bearing damage, steering loss, and driveline separation due to repeated improper torque and altered evidence. Independent Firestone and Honda technicians have verified these issues. The matter remains under active Hyundai Corporate Case #[XXX]. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Electrical system, Engine, Fuel/propulsion system, Nov 5, 2025
Unknown. 2018 Hyundai Sonata engine has failed. Only purchased the vehicle in December 2024, and the engine is defective. There is much information, via research, indicating that Hyundai is aware of the engine issues with this year vehicle, but are unwilling to make amends. Vehicle has 100,189 miles.
Engine, Oct 20, 2025
Engine consumes oil, more than 1 quart a week. started misfiring on a trip and dealer stated that engine needs to be replaced since valve was burnt. have 116k miles on car and have been diligent in maintenance.