2018 HYUNDAI SONATA Complaints
View complaints related to 2018 HYUNDAI SONATA. The complaints found here are submitted by actual consumers with first hand experience. There are more than 370 complaints submitted for the 2018 HYUNDAI SONATA. You can submit your own complaint to the NHTSA or call the Hotline, Monday-Friday 8am to 8pm at (888) 327-4236, TTY: (800) 424-9153.
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2018 HYUNDAI SONATA- Maryville, IL
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.
Source: NHTSA WEB SITE -
2018 HYUNDAI SONATA- Concord TWP, OH
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.
Source: NHTSA WEB SITE -
2018 HYUNDAI SONATA- Perrysburg, OH
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.
Source: NHTSA WEB SITE -
2018 HYUNDAI SONATA- Yardley, PA
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.
Source: HOTLINE VEHICLE OWNERS QUESTIONNAIRE -
2018 HYUNDAI SONATA- Lumberton, TX
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.
Source: NHTSA WEB SITE -
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2018 HYUNDAI SONATA- Bridge City, TX
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.
Source: NHTSA WEB SITE -
2018 HYUNDAI SONATA- Pensacola, FL
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 $10,000 on a loan for a failing vehicle. I am requesting Hyundai to investigate whether this vehicle qualifies for: •An engine recall, hidden warranty, or class action settlement •A buyback or goodwill repair INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Source: NHTSA WEB SITE -
2018 HYUNDAI SONATA- Houston, TX
The contact owned a 2018 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle sputtered, jerked, and lost motive power. The check engine warning light was illuminated. The vehicle was able to restart but made an abnormal ticking sound. The vehicle was taken to the dealer but was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 72,000.
Source: HOTLINE VEHICLE OWNERS QUESTIONNAIRE -
2018 HYUNDAI SONATA- Asbury park, NJ
Burning a lot of oil had car 11 months only drove a few month,now it’s a tapping sound dealer where i purchase will not help nor will Hyundai dealer 15,000$ 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.
Source: NHTSA WEB SITE -
2018 HYUNDAI SONATA- albuquerque , NM
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
Source: NHTSA WEB SITE