really awful
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
1,428 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2020 Hyundai Sonata engine problems

engine problem

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2020 Hyundai Sonata Owner Comments

problem #14

Jul 142023


  • miles


Engine leaks oil. I went to the dealer and they blamed the other Hyundai dealer saying they stripped out the drain bolt. After all the back and forth they told me they will replace the drain pan. I scheduled to have the car dropped off and wasn-??t given a loaner. When I went to pick up the car they told me the ac bolt and bracket are broken and to come on Monday but the drain pan has been replaced. I went home and the car continued to leak oil and when I went back to the dealer and called them out they came up with every excuse in the books. Bolt is stripped, impact to pan, and so on. Long story short I went to fix the oil pan and they damaged the ac bolt so instead of telling me to come back to do everything they said they did the drain pan but the bolt would have to be done another day. I am waiting on a loaner car as I waisted a whole day without a car and the issue wasn-??t fixed. I have a receipt showing the work was done but it never was. The dealer is dishonest and unprofessional. Not sure how they get away with this. They need to be held accountable.

- Spring Valley, NY, USA

problem #13

Apr 102023


  • miles
I noticed a strange smell almost like burning maple syrup in the garage for months. I thought it was just a different smell from Hybrid cars as I didn't have this used car very long. While driving at times the acceleration would stutter, again I thought this was just expected having never driven a hybrid car. Then on a trip a couple hours out of town someone stopped me on the road to tell me I was burning antifreeze and he could see white smoke coming from the car. I pulled over and didn't notice anything and continued driving but the heater wasn't working, it was blowing cool air despite the heat being on. I pulled into an auto parts store and got antifreeze in case. And then the overheating alert came on. I waited and filled it up and made an appointment at the dealer. They diagnosed it as a a blown gasket and a bad catalytic convertor and replaced all of that. After bringing it home I continued to lose coolant even with a two mile ride, I went from Max fill to half way between max and min. Clearly the problem wasn't the gasket or the catalytic convertor. Others have shared similar experiences online and had to have many parts replaced. The coolant tank, the EGR cooler (?), etc. I don't know what the problem is but something is wrong with these cars.

- Chicago, IL, USA

problem #12

Jan 212021

Sonata 4-cyl

  • miles
I have had the same issue 3 separate times related to the coolant system. The first time happened January 2021. I was driving on the highway and I noticed that when the car switched from electric to fuel a large plume of white smoke came out of the exhaust and then the engine overheating message started. I checked the coolant tank and it was completely empty. I managed to get some coolant in the car and get to my destination. I checked the coolant tank again and all the coolant that had been put in was gone. I immediately had the car towed to the dealer. They found the issue was a leak near the muffler and eventually replaced that and other gaskets. In May 2022, I noticed again that when I switched from battery to fuel on acceleration that there was a plume of smoke coming out of the exhaust and my coolant was very low. Brought to the dealer and they confirmed again there was a leak but this time with the EGR cooler and associated parts. In December 2022, I had just gotten an oil change from the dealer and they gave me a clean check up. The next evening I was on the highway again and I received the engine overheating message. I was able to get to the dealer the next morning after refilling the coolant twice. I provided them with the previous paperwork from the other two fixes. They confirmed again that the leak was happening with the muffler so they replaced more parts. In all I have for over 3 months fixing the same issue. I posted on Reddit to see if others have had the same issue and slowly more and more people with the same model year or the year after are reporting the same problems as seen https://www.reddit.com/r/Hyundai/comments/uhx7lf/coolant_leak_through_exhaust_on_2020_sonata_hybrid/?utm_source=share&utm_medium=web2x&context=3 Every time it's happened it's been covered under warranty but my concern is that it happens outside of the warranty and I will be on the hook for an expensive repair or forced to a new vehicle.

- Chicago, IL, USA

problem #11

Jan 072023


  • miles


While driving my cars a light starting blinking and my engine light came on and the car lost power This has happened on at least 3 occasions and I had to pull over upon starting the car after a few hours all returned to normal I reported this to dealer and they could not find a problem

- Lafayette Hill, PA, USA

problem #10

Oct 192022


  • miles
2020 Hyundai Sonata. Consumer writes in regard to grinding noise while driving. The consumer stated upon inspection by Toyota, it was discovered that the undershield had come loose and dragging.

- Omaha, NE, USA

problem #9

Sep 112022


  • miles
Steering parts being replaced many times, and the engine oil is low after I just got an oil change a week ago. Excessive engine oil usage with no idea where it is going.

- Massillon, OH, USA

problem #8

Jul 252022


  • miles


I first begin having an issue with the idle speed. It would jump up to 1,500 RPM, which is twice the normal 750 RPM level It started almost from the very beginning when I purchased this car new in early 2020. I mentioned it at first oil change at dealer at 3,500 miles. I was told it was normal. In the beginning it would come and go. Sometimes not happening for weeks in-between episodes. Then it started to have the check engine light come on after it would happen and stay on. I took it back while light was still on and they kept the car for several days. Said it was the EPV valve and replaced it. Car operated fine for a few days then started up again. It also started to idle up and down from 1500 down to 500 in a rapid succession. I was able to get it to stop sometimes by turning engine off and them back on. Again I contacted dealership and took car back in. They gave me a loaner car and kept my car for over a month. This time they replaced the computer they told me. I did not have car for more than a week before it started doing it again. It has gradually gotten worse and happens more often now. It has also started to have the Forward Collision Avoidance warning come on in addition to check engine light as well. Just this week it actually just died on me while driving and forced me to pull to side of road. Turn off the engine and restart the engine. This happen 3 times in succession. Dealership does not seem to have any idea on what is going on and have been not very helpful. 3 week wait to get an appointment to bring in and no loaner cars available. This problem with the 2020 vehicle is very dangerous. It can idle up at anytime and car will lurch, requiring forceful brakeing. Car dying while driving and losing power as well.

- Rowlett, TX, USA

problem #7

Feb 222022


  • miles
Check engine light came on and I contacted the dealer. Took 6 weeks to get an appointment and they advised that a module needed to be replaced giving me the impression it was a computer chip. The car has been sitting at the dealer since February 22, 2022, and they have been very cooperative including providing me with a free loaner to use. Unfortunately, they state that the part is not available (#HY25600-2J001 Thermal Management Module). Finding that this is not a unique failure as it is appearing inn 2020, 2021 models as well as some 2022 Hyundai models. Finding OEM part for sale on EBay, Amazon and even on the Hyundai parts website.

- Pompton Lakes, NJ, USA

problem #6

Jun 062021


  • miles
Driving, car started making a weird sound followed by a warning light on dashboard with dinging sound to correlate... car became difficult to gas, vehicle motion was lagging where I just knew I had to pull over Bc this car was going to literally stop began to slowly (Bc that-€™s all car would allow) to proceed forward and I was forced to come to a haunt as I pulled onto side of highway. I then could no longer move it. Turned car off for minute then returned to try to start again, car would not accelerate at all nor turn on fully.. I was forced to wait hour to get a tow... took to shop, no problem such was found, car started & ran again... this is 3 days later the car again continued the same exact pattern & I was unable to drive any further and forced to once again to get tow. This has to be something of bearings with engine, this car mode is not on list but IT certainly is an issue that I believe is related & should be rectified by Hyundai.

- Islip Terrace , NY, USA

problem #5

Nov 172020


  • 1,389 miles
On Nov. 17 while driving app. 65 mph on the highway the car suddenly shut itself off. All of the dashboard lights lit up & the car would not restart. After 10 min. Of trying to restart the car, the car started again, & all the lights on the car disappeared. The following day, while waiting in the turning lane at a red light, the car sputtered & turned off. All the lights on the dashboard lit up & the car wouldn't start I had the car towed on Nov 18 202 to a Hyundai dealership. The dealership reported that there was an internal short with the ABS module & the hydraulic module assembly was replaced. On, Nov 24, I was driving the car & the car stalled all the warning lights went back on. I had the car towed the dealership where it stayed until December 11 the dealership stated that they could not find anything wrong with the car. I picked up the car on Dec 11 & the car appeared to be working normally. However, on dec19, while stopped at a red light, the car began to shake back & forth at idle & the rpms started to go up despite my foot being on the brakes. The car behind me saw what was happening & helped me pull over to the side of the road. I had the car towed to the dealership yet again. The dealership stated that they were able to duplicate the issue on Dec 23, 2020. However, no fix was done to the car. The dealership claimed that the car was in a 'relearn' process & it would need more time for the car to 'relearn' how to drive again. Everything seemed okay after the Dec 23 incident until Feb 8 2021 when I tried to stop while in traffic & the brakes would not work at all. I narrowly avoided getting into a major accident & once again brought the car to the dealership. The dealership found that the master cylinder assembly was internally defective & was not holding pressure and as a result the brakes were not working. The vehicle was returned to me on Feb 11 2021.

- Far Rockaway, NY, USA

problem #4

Mar 202021


  • 14,698 miles


The contact owns a 2020 Hyundai Sonata. The contact stated while driving 35 mph and entering the highway, the vehicle would not shift into gear and the vehicle was sputtering. The contact stated that the vehicle would not exceed 45 mph. The contact pulled onto the shoulder of the highway and shut-off the vehicle. No warning light was illuminated. The contacted restarted the vehicle however, the failure persisted. The contact pulled off the highway and had to restart the vehicle several times. The vehicle was taken to the local dealer - webb Hyundai merrillville (1000 81st ave merrillville in 46410, (219) 249-4961) where the diagnosis was not determined for the engine however, the contact was informed that the heating system was faulty and the instrument panel failed to provide an accurate warning light for the failures. The vehicle had not been repaired. The manufacturer was notified of the failure but, did not provide any further assistance. The failure mileage was 14,698.

- Hobart, IN, USA

problem #3

Mar 132020


  • 1,200 miles
My car stalled and stuttered between 1000 and 1500 miles in traffic and couldn't get it into gear once started. It was the fuel rail sensor. Now at 6000 miles did same thing. If sits for bit works again. It also reset itself and I lost all preprogrammed information. The gas door also opens at times when unlock driver door. The dealership had it the first time for over 30 days and had to contact engineers to fix it.

- Beverly Hills, FL, USA

problem #2

Jul 132020

Sonata 4-cyl

  • 1 miles
Vehicle abruptly stopped in a traffic signal without giving any indications what so ever. When tried to restart it stalled pretty badly causing excessive vibrations. This had just 1900 miles on it. Vehicle didn't have any mil or any visible information about the issue. It created a huge traffic pile up due to the peak hour in which this problem started. Few days ago there was issue with starting but it resolved after couple of minutes, this time the vehicle had to be towed to the dealership and I lost my days work and pay. Biggest concern is how abruptly it stopped in a busy street.

- Laurel Springs, NJ, USA

problem #1

Jul 072020

Sonata 4-cyl

  • 2,700 miles
Vehicle rough idled & eventually shuddered to a stop. This happened four times while in gear and idling at appx 1000-1500 miles. Between 1500-2000 miles, vehicle shut down while driving appx 60mph on a county road. At appx 2700 miles, mpgs drastically impacted when vehicle suddenly stopped shifting gears properly while in motion at appx 70mph on the highway. Check engine light appeared with message regarding ecs issues. Vehicle still drives, it just seems to struggle with efficiency and shifting correctly.

- Council Bluffs, IA, USA

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