2018 Hyundai Sonata engine problems

Related recalls

No recalls on file.

What owners say

1. Filed Oct 5, 2026NCBody & StructureEngine

   What component or system failed or malfunctioned, and is it available for inspection upon request? The paint is peeling off the car, when I went to the dealership they said this is a known problem for 2015-2018, but they can't fix it there is no recall. It is causing rust. The valve cover gasket leaks oil and caused spark plugs to blow twice. How was your safety or the safety of others put at risk? The valve cover has caused my wife to be stuck on the side of the road early…

   NHTSA complaint #11769166 · source
2. Filed Sep 21, 2026ILEngine

   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.

   NHTSA complaint #11765780 · source
3. Filed Aug 25, 2026NCEngine

   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.

   NHTSA complaint #11759477 · source
4. Filed Aug 16, 2026NCBody & StructureEngine

   The paint on all parts of the car is completely coming off down to bare metal. It’s as if the car wasn’t prepped to receive paint. Every Hyundai I pass that’s white the paint is coming off. There is also an internal engine oil leak where I’m losing 4qts of oil a week.

   NHTSA complaint #11757263 · source
5. Filed Aug 16, 2026TXEngineTransmission & Drivetrain

   I recently had the 9C2 Emissions recall update performed on my car, and since the update my car drives like total garbage after a cold start. It hesitates to accelerate, it bucks when trying to accelerate, and it’s to the point the engine is about to stall. I took it back to the Hyundai dealership and they said they are aware of the issue, but there is no fix from Hyundai at this time. This is a major safety concern, as the car barely wants to accelerate after a cold start.…

   NHTSA complaint #11757253 · source
6. Filed Jul 20, 2026TXEngine

   The lower aluminum engine oil pan developed a structural hairline fracture ("micro-crack") directly along the factory casting ridge adjacent to the drain plug. The component failed without any external impact, road hazard, scraping, or underbody damage. The failure was officially confirmed and documented by Eckert Hyundai during a service visit on July 13, 2026 (Case #42971835). Following the dealer oil service, the fracture degraded into an active, worsening oil drip that…

   NHTSA complaint #11751641 · source
7. Filed Jul 6, 2026OHEngine

   I purchased my vehical at Car Culture in Warren, Oh. The dealer said to only take it there for maintenance, so I did as required. Whenever the check engine light came on I would bring it there and they would say it was a sensor and they fixed it. And one day it started miss firing and the light came on again. When I took it to the dealership, they said it needed oil to bring it in every 2 weeks to top the oil off. And so I did that and finally the car was getting worse at…

   NHTSA complaint #11748511 · source
8. Filed Jun 19, 2026NJFireEngine

   Vehicle caught fire after repeatedly taking it to Hyundai for service . I complained about the oil consumption and knocking noises while the vehicle was still under warranty and it was denied.

   NHTSA complaint #11745212 · source
9. Filed Jun 16, 2026OHEngineTransmission & Drivetrain

   Check engine light solid/engine failure while driving. 2018 Sonata SE purchased new in fall 2018. Around 50,000 miles started noticing oil level drop and had to add more before next scheduled change. Dealership service center said I just had to shorten the mileage between changes which didn't seem appropriate for a vehicle with 50,000 miles but I did. Continued to have oil consumption problem with no signs of leak, no burning oil smell or exhaust issues. Dashboard display…

   NHTSA complaint #11744559 · source
10. Filed Jun 11, 2026ILEngineTransmission & Drivetrain

    Following completion of Service Campaign 9C2 (ECU software update, TSB 25-01-087H) at a Hyundai dealership, my 2018 Sonata immediately exhibited drivability changes that were not present before the service. Symptoms include altered shift timing, hesitation, and rougher throttle response — particularly noticeable during the first several minutes of driving. These symptoms began on the first drive after the recall update was applied and have been consistent since. The vehicle…

    NHTSA complaint #11743622 · source
11. Filed May 26, 202647,575 miILEngineTransmission & Drivetrain

    The contact The contact stated that when taken the vehicle for a service campaign repair and shortly after went for recall r The vehicle does not run properly on cold starts, the RPMs increase rapidly and slow down, vehicle jerks forward once beginning to drive.. The vehicle does not have this issue once the vehicle is warm. The manufacturer was not notified of the issue. The approximate. Failure mileage was 47,575.

    NHTSA complaint #11740030 · source
12. Filed May 12, 2026CAEngineFuel, Hybrid & EV PropulsionTransmission & Drivetrain

    Engine blown out malfunction took two dealer Hyundai Folsom Lake stated rings are bad sludge buildup in engine and stayed at Hyundai motor America denied engine replacement due to knowledge under Theta two engine extended warranty settlement of 150,000 MI 15 years I'm still within warranty but are still being denied had numerous of issues with vehicle oil consumption knock knock sensor replace and other maintenance done since purchase vehicle brand new in 2018

    NHTSA complaint #11737468 · source

Source: U.S. National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation public data. Complaints are submitted by owners and are not verified by NHTSA or by us; a complaint does not prove a defect exists. View this vehicle on NHTSA.gov Methodology