2018 Hyundai Sonata Problems

Half of the owners who gave a mileage had the problem by about 24,000 miles.

What to check before you buy

• Ask the seller not to warm the car up, and start it cold. Listen for ticking, knocking or a rough idle in the first minute.
• Pull the oil dipstick and the oil cap. Low oil, a gasoline smell or a milky film on the cap are reasons to walk away or get an inspection.
• Plug in an OBD2 scanner. Stored or pending codes matter, and so do readiness monitors that show "not ready", which usually means the codes were cleared right before the sale.
• Ask for oil change records. A gap in the records on a model known for engine complaints is a negotiating point at minimum.

Tools that help

What owners said

Hyundai dealership confirms I am in need of a new engine due to large oil consumption which is a known issue on 2018 Hyundai Sonata engines. Hyundai will not approve repairs because I am the second owner and vehicle is out of the 5 year warranty period. I only have 52K miles on my vehicle.Owner complaint, filed 2026

Since I had Service Campaign 9C2 completed, the car hesitates to start, does a mini-lurch upon cold start and runs rough. Two weeks ago, it was put in park, lurched backwards, then died. The starter and battery have been replaced but this has not helped. The car ran fine before this update was done.Owner complaint, filed 2026

Half of the owners who gave a mileage had the problem by about 21,000 miles.

What to check before you buy

• Test every switch: windows, locks, mirrors, seat heaters, the screen, the backup camera, Bluetooth and every USB port.
• Watch the dash at startup. Every warning light should come on briefly and then go out.
• Have the battery and charging system tested. A weak alternator or battery drain shows up here.

Tools that help

What owners said

Odometer Fraud. The contact purchased a 2018 Hyundai Sonata. The contact discovered a mileage discrepancy while searching the vehicle history report. The contact stated that the odometer indicated several readings. The vehicle was a dealer sale. The contact was unaware that at the time of purchase, the vehicle mileage was 148,000. The…Owner complaint, filed 2025, at 148,000 miles

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…Owner complaint, filed 2025, at 125,000 miles

Half of the owners who gave a mileage had the problem by about 41,000 miles.

What to check before you buy

• Drive it from cold if you can. Shifts should be smooth in every gear, including reverse.
• Feel for slipping (revs rise without the car speeding up), shudder at low speed and a delay when you put it in gear.
• Listen for whining, which is a common CVT complaint, and clunks when you go from drive to reverse.
• If it has 4WD or AWD, engage it on the test drive and ask when the transmission and differential fluids were last changed.

Tools that help

What owners said

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 failingOwner complaint, filed 2025

Starter replaced at less than 50,000 miles. Normally a starter will last 150,000 miles or more. I was past the warranty by 9 months but was under the mileage. Warranty was 5 years or 50,000 miles. Hyundai parts are cheap and do not last long compared to other companies.Owner complaint, filed 2024

Half of the owners who gave a mileage had the problem by about 92,000 miles.

What to check before you buy

• Smell around the engine bay and under the rear of the car for raw fuel.
• On the test drive, accelerate firmly from a stop and up a grade. Stumbling, surging or a flashing check engine light are red flags.
• Fuel pump recalls are common. Check this exact VIN for open recalls before you buy.

Tools that help

What owners said

The vehicle experiences a severe delayed start/extended crank condition before finally starting. This is caused by a loss of fuel pressure prime due to the defective fuel filter housing leaking internally, creating an unpredictable and unsafe vehicle operation hazard. The dealership is denying coverage under the 15-year/150,000-mile…Owner complaint, filed 2026

My car stalls while driving and then I try to restart it but nothing happens. After reading online about the fuel pump issues and extended warranty related to the fuel pump I took the car in for repair. My car has 75,000 miles and the extended repair on this is for 150,000 miles/15 years. The dealer is refusing the repair because my car…Owner complaint, filed 2026

Half of the owners who gave a mileage had the problem by about 1,000 miles.

What to check before you buy

• Check every light: headlights on low and high, fog lights, brake lights, turn signals and reverse lights.
• Run the wipers on every speed with washer fluid, and run the defroster front and back.

Tools that help

What owners said

THE HEADLIGHT LOW BEAMS ARE DANGEROUS AND NEED TO BE RECALLED ASAP? After his death, I acquired this vehicle from my father who had stopped driving at night thinking he had developed a vision issue. The first time I drove it at night I discovered the low beams are defective, and that was the problem, not my dear old Dad’s vision. The…Owner complaint, filed 2025

Back up lights. The lights constantly burn out causing the harness light holder to burn out. The lights will not come on even after replacing fuse and lights There are not back lights to warn patrons on the road for turning or stopping Yes it was taken to a dealership No it has not been inspected my either , but there is a recall on…Owner complaint, filed 2025

Half of the owners who gave a mileage had the problem by about 32,000 miles. Parts named most: Body (14).

What to check before you buy

• Look underneath with a flashlight. Utah road salt is hard on frames, brake lines and the bottoms of doors.
• Open and close every door, the hood and the liftgate, and lock and unlock each one.
• Use a paint thickness gauge and compare panels. A panel that reads very differently from the rest has likely been repaired.

Tools that help

What owners said

The trunk latch on the Hyundai Sonata malfunctioned, and our safety was put at risk when the trunk malfunctioned while driving on the freeway, obstructing the back view. After several attempts to try to close the trunk and after doing some research, I learned it had a vehicle recall, 21V619000. An appointment was made at Ontario Hyundai…Owner complaint, filed 2026

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…Owner complaint, filed 2025

Half of the owners who gave a mileage had the problem by about 10,000 miles.

What to check before you buy

• The pedal should feel firm and the car should stop straight without pulling, grinding or a pulsing pedal.
• The ABS and stability control lights should go out after startup and stay out.
• Look through the wheels at the rotors. A deep lip on the edge means brakes are due soon, which is a fair thing to negotiate on.

Tools that help

What owners said

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…Owner complaint, filed 2025, at 40,000 miles

The contact owned a 2018 Hyundai Sonata. The contact stated that while driving at 35 MPH, a pedestrian alerted him that the vehicle was on fire. The contact noticed that the rear portion and driver side of the vehicle was on fire. While traveling around a curve the brakes became inoperable the contact jumped out of the vehicle. he…Owner complaint, filed 2024, at 105,000 miles

Half of the owners who gave a mileage had the problem by about 9,000 miles.

What to check before you buy

• On the test drive, press the gas gently and firmly. The response should be smooth with no lag or surge.
• Set the cruise control, then use resume and cancel to make sure each one works.

Tools that help

What owners said

The contact owns a 2018 Hyundai Sonata. The contact stated that while her daughter was reversing out of a parking space, the vehicle experienced unintended acceleration. The vehicle drove forward and crashed into a brick post. The contact's daughter did not sustain any injury but later received medical attention. There were no airbags…Owner complaint, filed 2022, at 41,000 miles

The contact owns a 2018 Hyundai Sonata. The contact stated that while braking and pulling into a parking space, the vehicle reeved up, accelerated forward, and crashed into a wall. There were no reported injuries, or air bag deployment. The vehicle was towed to the local dealer where they were unable to duplicate the failure after a road…Owner complaint, filed 2021, at 20,000 miles

Half of the owners who gave a mileage had the problem by about 47,000 miles.

What to check before you buy

• Pull out and latch every seat belt, and let each one retract on its own.
• Try every seat adjuster, and watch for a passenger air bag "off" light when an adult is in the seat.

Tools that help

What owners said

The contact owns a 2018 Hyundai Sonata. The contact stated that upon entering the vehicle, the contact became aware that the driver’s side seat belt failed to latch securely into the buckle. The seat belt warning light was illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the seat belt buckle. The vehicle was…Owner complaint, filed 2025, at 45,000 miles

The drivers seat operation is going berserk. I can not get it to move at times and at other times it only partially operates. It also may do the opposite of what control direction I move it! I had to drive home today not being able to to the gas pedal well...very dangerous.Owner complaint, filed 2023

What to check before you buy

• Turn the wheel lock to lock while parked and listen for groaning, clicking or binding.
• On a straight road the car should track straight with the wheel centered and no loose feeling.
• A power steering warning on the dash, even briefly, deserves a mechanic’s look before you buy.

Tools that help

What owners said

Lost control of the car - the car was brought in to Hyundai Maxon in Union, NJ and were told the steering column was defective and the car is not safe to be driven, needed a steering column replacement. Dropped the car off 12/12/2024 and was quoted for the replacement of the part (with a new one). On January 17, 2025, 36 days after the…Owner complaint, filed 2025

I was driving and tried to make a turn when the steering wheel gave out on me unexpectedly. This lead my car to continue forward onto the other lane of oncoming traffic. The steering wheel signal also turned on. When my car was finally able to turn and I arrived at my destination, I parked my car for 2 hrs. After it was time to leave the…Owner complaint, filed 2022

Parts named most: Automatic emergency braking (5).

What to check before you buy

• Where it is safe, try the adaptive cruise and lane keeping on the test drive and watch for sudden braking or warnings with nothing there.
• Check the windshield in front of the camera and the bumper sensors for cracks, chips or poor repairs.
• Ask whether the windshield has been replaced. The camera has to be recalibrated afterward, and many shops skip it.

Tools that help

What owners said

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…Owner complaint, filed 2025

Warning lights keep coming on for ABS and Blind Spot Detection. Please help as I know this has been recalled in other 2018 Sonatas. So why is my VIN # not included in these recent recalls?? I FEAR for mine and my daughter's safety as she turned 16 in February 2023 and started driving this car in August 2023. PLEASE HELP!!Owner complaint, filed 2023

What to check before you buy

• Drive over a few bumps and potholes slowly with the radio off and listen for clunks or rattles.
• Check the tires for uneven wear on the inside or outside edges, a sign of alignment or suspension trouble.
• Look behind the wheels for oily, wet shocks or struts.

Tools that help

What owners said

Vehicle has been making a clunking noise (front passenger area). Brought to independent service center where they determined that the strut tower is failing. Current mileage 66000. Appt set for Checkered Flag Hyundai to evaluate on 9/11/2026.Owner complaint, filed 2026

Was driving a brand new hyundai sonata 2018 vehicle for a week with 300 miles on it and was about to exit on a freeway ramp, but suddenly lost control of the steering. The vehicle had to be towed and when the mechanics at the hyundai dealership took a look at the vehicle, they were unsure of how the lower arm assembly on the front…Owner complaint, filed 2018, at 300 miles

What to check before you buy

• The air bag (SRS) light should come on at startup and go out within a few seconds. If it stays on, the system may not work in a crash.
• Air bag recalls are some of the most serious. Check this exact VIN for open recalls and get proof any recall work was done.

Tools that help

What owners said

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.Owner complaint, filed 2026

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…Owner complaint, filed 2025

What to check before you buy

• Read the four-digit DOT date on each tire. Tires older than about six years should be replaced, whatever the tread looks like.
• Check tread depth on all four. On AWD vehicles all four tires should match.
• The tire pressure light should go out after startup.

Tools that help

What owners said

the Kumho 205/65 R16 treads are losing chucks of rubber on 3 tires with just under 17000 miles as of this date 7/24/23 and under 6 years old. ( their warranty states 60K or 6 yrs) Kumho will not warrant the tires in any way shape or form. Have tried to get some help from them since Jan of this year (2023) with no results. Also the…Owner complaint, filed 2023

The contact owns a 2018 Hyundai Sonata equipped with Hankook Tires, Tire Line: Kinergy ST, Tire Size: 205/65/R16, DOT Number: (N/A). The contact stated that three of the four tires had failed. While the vehicle was in for a Vehicle State Inspection, it was discovered that the rear passenger’s side tire was deformed and wobbly which cause…Owner complaint, filed 2022, at 28,000 miles