general problems of the 2018 Hyundai Sonata - part 1

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.

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.

When starting car warning lights came on for abs, aeb, cruise control. Cruise control is locked out and not working due to these warnings.

Check engine light keeps coming on got it looked at , certain parts replaced & it’s still on something to do with the air filter.

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.

I have to put a quart of oil in every week. It burns oil.

Panoramic sunroof came loose on highway and bent up 90 degrees making vehicle undrivable.

43000 miles on car. Original owner. New battery. Car does not cold start in the morning. All electronics light up, but engine doesn't start. This is a known issue from all the posts I found online, yet Hyundai has not issued a recall. I paid 300 for a battery 2 weeks ago and the issue didn't resolve. Now I am being told by dealer it is the starter and it's not covered because my 5 yr warranty is expired (my car is 6 years old). This is a known safety issue across the 2018 Sonata line. This should be a recall or bulletin, instead I have to come up with hundreds of dollars more to replace a starter on a car with only 43,000 miles.

When I bought the car from mathews in marion ohio the car looked like it was already in some form of accident due to a previous owner and I was unaware what caused the accident or any other problems with the vehicle upon buying. I was not presented with a carfax. I have electrical tape at the bottom of my bumper and there’s a problem with acceleration. It accelerates by itself and veers right when I take my hand off the wheel. I’m afraid to drive my car on the highway. I have complained about this problem to mathews twice. I am now in a loaner until they figure out what’s going on.

My 2018 Hyundai Sonata with only 20,821 had to have the starter replaced on [xxx] because the car would not start. I had 3 different people including aaa road service to verify why it would not start and what the problem was. I end up having my car towed with aaa to a local mechanic shop, mike hepler auto repair st. Cloud florida 34769 407-593-0152, and mike did the diagnosis saying the starter was bad it was(fried) as he put it. He said he could replace it for $492. 17 for part and labor which I accepted for him to do the job. I had left numerous messages (4)for my local Hyundai dealership service department to call me to let get a diagnosis and no one has ever called me back to give them my information or ask any questions.

? 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.

The paint if pealing off in large sections due to a manufacturer defect in the primer. The flakes can fly onto the windshields of other vehicles causing collisions.

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.

For now the fifth time in the last 16 months the hev light and engine light has lit up while the car jerks and sputters and dies. Below is the incident report that I filed on or about August 8, 2022. Again at the end of the day yesterday on October 20, 2023 the same issues still arise for the fifth time. See below for a re-cap of the issues I am once again experiencing after Hyundai claims to have fixed the issues: for the fourth time the hev light (and others) has come on and the dash has lit up while I was driving, with the last three times leaving us stranded in dangerous road situations with little or no power. The light first came on in July 2020 at 40,089 miles. A dealership reset the codes and I had no problems until June 7, 2022 when the lights lit up on the dash again and the car died and I had to have it towed to a local dealership. They could find nothing wrong with it and checked all the wiring and said none of the codes were coming up and that the car ran fine for them when test driving a day or two after I had it towed. So they released the car back to me deeming it good to go. Then only 19 days later on June 26, 2022 the hev light among other lit up again and the dash indicated to pull over and cut the car off due to the hybrid system. I had it towed to the nearest dealership again. The then looked at it and said they reset all the codes and everything looked to be good to go. Then again on Aug 8, 2022 (3rd time in two months), we were put in a dangerous situation trying to get the car off a busy highway when the hev light (and others) again lit up the dash and our power went almost completely out while the engine jerked violently as we tried to avoid being hit by cars while trying to get off the highway before it completely died on us. Four times now Hyundai dealers have shrugged this off saying "we reset the codes" and we can't find an issue. We have been put in dangerous traffic conditions three of these times.

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!!.

Unknown. I noticed that there was a check engine light on and I took it to autozone to have it checked out, they told me that it was coming back with the code of an O2 sensor. I thought nothing of it until it started not wanting to start right. On July 1, 2023 I took my car in to the dealership for an oil change and they never said anything about why my car was doing a delayed start. It would eventually start but it took at least a minute. I bought a new battery from walmart to put in my car so that it would not do the delayed start, but it kept doing it anyway. Finally decided to take it to a mechanic and the first time that he started it took at least a minute, he realized that he didn't have his computer (code reader) with him so he turned it off. When he returned with the code reader he plugged it in and started the car then it started smoking, smoking turned into fire that caused the entire underside of my hood to melt including engine, electrical harness, belts, battery and much more. If it wasn't for the mechanic's quick thinking by putting out the fire while calling 9-1-1, the fire would have gone to the fuel tank and exploded. Yes, the safety of others was put at risk.

When driving the car on the highway - "check engine - hybrid system" warning lights come on and indicate hybrid system issue and to shut car off immediately. Extreme safety issue as the car goes from highway speeds to 35mph almost instantly. This has happened seven times now and Hyundai keeps indicating that technicians are following engineering guidance in fixing the issue related to the knock sensor. The seventh occurrence happened on may 23rd of 2023. First one was in December 2021. As Hyundai is unable to correctly fix the issue I have repeatedly asked for them to replace the car since it is an extreme safety issue but they will not do so. Still waiting for diagnosis of the latest occurrence from may 23rd. Hyundai does not acknowledge that this issue is of safety concern and just indicates that the issue has been fixed each time it occurs.

2018 Sonata has white paint peeling on hood of car - only 29,930 miles on car.

Hyundai boosted about their emergency response system included with my vehicle and charged extra. They failed to tell me that they were discontinuing the system. If I crash and need assistance bc I'm unconscious, I won't get it.

For the past 3 oil changes, I find myself having to add 5 quarts of oil to my car after driving over 1,000 miles from getting my oil change. This third oil change I have added 15 quarts of oil to my car due the check oil light comes on. When I first purchased this car in March 2021, I didn’t experience this issue. I’ve never had to add oil to my vehicle before an scheduled oil change. Whalen the oil is checked due to the light coming on, it’s boned dry.

This car will not start when it is cold. I have only had this car for over one year and four months. The car ran perfect up until we began to have extreme cold weather. This is so dangerous because it could be an emergency and my car will not start. I have done my research and discovered that this is an ongoing issue with Hyundai. And nothing has been done about it.

2018 Hyundai Sonata sport+ with 23k miles that has white pearl exterior paint. The paint (w8 or ww8) is peeling off from several locations (hood and roof). This has been a know issue with this type of paint on Hyundai vehicles but manufacturer is not taking any responsibility that paint or paint job is defective. One can google this issue and thousands of user complaints are there of different forums and messaging boards. Example: https://community. Cartalk. . Read more...

We drive a 2018 Hyundai Sonata with Hyundai quartz white pearl (w8) paint. It has 62000, so just out of regular warranty. Last week I noticed that we were missing a huge chunk of paint on the roof. As a regular passenger of this car, neither of us noticed anything wrong with it until it was gone. It looked like it just bubbled up suddenly and peeled off. We took it into our local Hyundai dealer and they told us it was out of the 36k mi. Paint warranty. They didn't even look at it. We paid for an extended warranty because they served us so well on our other Hyundais up to that point. I called the consumer line like they suggested and found no recalls. When I tried to get a human, I was met with silence. No indication that the call had gone through. I went next door to there collision center and got an estimate anyway. The man there didn't have to see any more than one picture to know that it was a Hyundai. They service multiple of that owner's various different branded dealerships. Obviously, this wasn't his first rodeo with this problem. He quotes $1200 to put a bandaid on the problem. However, there are numerous incidents of consumers facing the same issue with there Hyundai/kia vehicles. I have a friend who had the same problem on a similar year Acura with pearl paint. I'm filing this complaint because it is obvious that Hyundai/kia are not going to own up to this. The first class action suit was dismissed and the problem persists. They are still using the paint to this day and the same delamination problems keep appearing. I do not want to be driving down the road and have a huge slab of paint fly off and hit someone else's windshield. This issue needs to be investigated before someone gets hurt, not after.

The white paint is peeling off the vehicle.

For the fourth time the hev light (and others) has come on and the dash has lit up while I was driving, with the last three times leaving us stranded in dangerous road situations with little or no power. The light first came on in July 2020 at 40,089 miles. A dealership reset the codes and I had no problems until June 7, 2022 when the lights lit up on the dash again and the car died and I had to have it towed to a local dealership. They could find nothing wrong with it and checked all the wiring and said none of the codes were coming up and that the car ran fine for them when test driving a day or two after I had it towed. So they released the car back to me deeming it good to go. Then only 19 days later on June 26, 2022 the hev light among other lit up again and the dash indicated to pull over and cut the car off due to the hybrid system. I had it towed to the nearest dealership again. The then looked at it and said they reset all the codes and everything looked to be good to go. Then again on Aug 8, 2022 (3rd time in two months), we were put in a dangerous situation trying to get the car off a busy highway when the hev light (and others) again lit up the dash and our power went almost completely out while the engine jerked violently as we tried to avoid being hit by cars while trying to get off the highway before it completely died on us. Four times now Hyundai dealers have shrugged this off saying "we reset the codes" and we can't find an issue. We have been put in dangerous traffic conditions three of these times.

On the way home from the produce store today, the engine seemed to stall or seize while I was driving and the car reacted in a jerky manner. I kept going, as I was close to home, but could only travel about 20 mph, and it would periodically feel as if it were about to conk out. Check engine light came on at this point. Made it home, but no longer feel safe driving it. Am online now, searching for what to do. What I experienced sounds like the engine recall problem others have experienced, although my 2018 Hyundai Sonata is not on the recall list. Perhaps it should be.

My car was serviced at Hyundai dealer for other problems while my car was being serviced the service department said they fixed a recalled latch on trunk I never had problems with trunk before the so called recall was fixed now my trunk is stuck close and pops open and is very hard to close once open you have to slam it shut once shut it will not open I had a tail light out I press the button to open the trunk and after riding around for three days it popped open and I fixed the tail light within 3 weeks the tail light is out again and my trunk is still stuck shut I called the dealership and it’s seems as though it’s not important and been giving appointments so far away.

This vehicle consumes one quart of oil every 1000 miles. I have documentation to prove it. Hyundai has done their own asessments and claimed that it consumes less. There was a class action lawsuit filed in California for this issue.

2018 Sonata hybrid may 19 - "check hybrid system turn engine off" appeared on the dashboard. Vehicle brought to dealership. May 22 - I pay for a rental vehicle may 26 - dealer states vehicle is ready and they performed service campaign 966. May 27 - my rental car is returned. Dealer picks me up and I go to dealership. I get into my car and "check hybrid system turn engine off" appeared on the dashboard. Vehicle never driven off dealership lot. Dealership pays for my rental this time. June 10 - dealer states vehicle is ready and they performed service campaign 966 (dealer says there are 2 software updates and the first time they only did 1). I return rental and pick up my vehicle. June 11 - "check hybrid system turn engine off" . I go to dealer. Dealer turns off check engine light and tells me vehicle is safe to drive and bring the vehicle back on the 13th (Monday). Dealer affirms vehicle is safe, they cannot get me a car rental today and my vehicle is fine. I drive the vehicle home. Some time later, check engine light comes back on, vehicle loses power (engine cuts off?) and stalls in the intersection. I immediately turn on hazard lights. Depleting the hybrid battery (?) I am able to slowly bring the vehicle into a parking lot right after the intersection before I lose (all?) power. Vehicle is towed to dealer. June 13 - picked up a 3rd rental car.

Purchased a certified pre-owned 2018 Hyundai Sonata - found out recently the car is burning/losing oil- a few weeks after having an oil and filter change my oil warning light started flashing while driving. . Checked engine oil and could not believe that oil was almost empty. . Major concern is for major engine malfunction and possible locking up while driving- which could be fatal !!! now I have to monitor oil levels/consumption every other day- I have contacted Hyundai and they're suggesting that I be without transportation while they take an undetermined amount of time to test the vehicle which is unacceptable !.

During the drive, check engine lights on then suddenly, hev warning lights with turn off the engine with critical alert sound. I was drove again after attempting to start several times then again & again. . . It freaked me out when I drove on the highway, and yet to fixed & afraid to go to the dealer becase of cost & uncertain reasons. This could be big accidents on the highway.

The shark fin antenna assembly becomes dislodged from its base very easily and can fly off while driving or scraping ice off the roof with minimal force. Hyundai should do a better job attaching the outer shark fin plastic cover to its base.

The overhead console does not close. It does it all the time. I know there was a recall on it but not on the 2018 model. It is a problem because it blocks your view on the right side thank you.

When the car is cold it would not start. I checked what the problem can be online and it turns out that there are a lot of out cars with the same problem. The problem is starter. Sever people after changing the starter there vehicle was fixed. Another problem is sometimes the blind spot warning system does not work. These problems are reported by people with the same car but not by dealers.

Unknown— engine has been making noises, vehicle keeps breaking down (engine issues, alleged starter) and Hyundai dealerships keep ignoring and not documenting my complaints and passed the vehicle for all inspection after others have documented some of my complaints that I brought to them. They simply didn’t want to do any work because it was covered under bumper to bumper warranty until I threatened to call Hyundai USA with a lawyer and my engine problems were never addressed or examined by the Hyundai dealer in my area even though I specifically kept complaining about my car seizing and stopping on me in the middle of the highway with my toddler in the vehicle! it’s doing it again and no one at anything Hyundai cares! I’ve been lied to and passed on for over a year now and the problems list keep getting longer and longer! I was told that the engine was replaced in March 2019 and that was that. . I was dismissed! no more questions asked when I made my complaint directly to Hyundai USA this time!.