2019 Hyundai Sonata: misfire or rough idle

Filed Aug 18, 2026 · Engine · 140,000 miles · FL

The contact owns a 2019 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle experienced severe overheating and excessive oil consumption. The contact also stated that there was a misfire in the engine even though the spark plugs and ignition coils were replaced. Due to the failure, the vehicle could not be driven with the air conditioning activated. Additionally, the engine was knocking and shaking abnormally, causing an oil leak and a smoke odor due to the oil burning. The vehicle was taken to a dealer, where an engine replacement was recommended. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 140,000.

Filed May 5, 2026 · Engine, Suspension · IL

Ecm, p0303, yes, not yet, no, cel light before the car was brought to the dealership, 2019 Hyundai Sonata SE, 2.4L Theta II GDI. Perryville Hyundai IL refused applicable TSB in writing 5/4/26 despite active P0303 misfire, fuel-in-oil smell, crankcase pressure. I have Photos prove falsified multi-point inspection: 1.0 inch (.0833') wheel well discrepancy, same mileage in/out. Vehicle has stall risk. Case Manager [XXX] non-responsive 2hr 45min after requesting written tow instructions on safety matter. RSPM escalated 1:00 PM CDT 5/5/26 with 3:00 PM deadline. No contact received as of 3:03 PM. Vehicle unsafe to drive. Theta II Lifetime Warranty Settlement violation. Case #XXX. Requesting federal investigation. Photo upload is not working, I'll need a email to send them in apparently INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 5, 2025 · Engine · OH

The car stalled and came to a stop on the highway which was very dangerous. Took it to mechanic and they found the cylinder 3 and 4 misfire and suggested we take it to hyundai dealer for repair. Took it to hyundai dealer and they did a compression test and found only 40% compression in cylinder 4. All cylinders should be around 180%. Engine needs to be replaced and hyundai refuses to help.

Filed Dec 23, 2024 · Engine, Fuel system · 115,000 miles · OH

What component or system failed or malfunctioned, and is it available for inspection upon request? Since april 2025 i’ve been having low oil readings in my vehicle despite regular oil changes I took it into the dealer since my vehicle was still under warranty, which they stated only one part was under warranty. I had to pay $800 after this was replaced. I started having engine light come on. This engine light when I paid a diagnostic fee I learned that the cylinder three was misfiring. It was suggested that I have an oil change and get the oil level checked again within a week. This was done and it was determined that it was burning too much oil. I submitted this to the insurance and was told that this was not covered that there must be another reason why this was not working the way it should. 3 weeks ago Then I was asked to replace the spark plugs and coils. These were replaced for an additional cost of approximately $300. After replacing this, the check engine light gave the same condition of third cylinder damage.. And the oil level continue to decrease The vehicle was left with the dealer for approximately 10 days. They stated that the engine needed to be cleaned due to possible carbon buildup for about $800 then they stated that the spark plugs and coils needed to be replaced with a specific brand and not the type that Was previously used. Then my vehicle was returned to me, performing sluggishly with the check engine light returning with the same condition of third cylinder misfire. An inspection is available. How was your safety put at risk? The possibility engine failure away from hom Has the problem been reproduced or confirmed by a dealer or independent service center? Yes twice Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? No Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? Yes frequently over the last 2 months

Filed Oct 29, 2023 · Engine · CT

I bought this car 1 year and 2 months ago from a Hyundai dealership. The car was close to 73,000 miles. A few days after I got the car I started hearing this noise that sounded like a rattle coming from the front while accelerating to about 2,000 RPM. Due to my work, I went back to the dealer after 1,000 miles and explained to them about the noise and they duplicate it. The engine was consuming oil when I bought the car, I went back to the dealer and never did any testing on oil consumption. The problem got worst and worst. I started a claim with Hyundai Corp and I waited for 4 months to the an approval and they are only covering 50% of the engine. Dealer says I have to pay $3,200 to start engine replacement process, with no payment plan. Now I have a debt of $17k and no car. Engine has no compression on cylinder 3, which causes a misfire and makes the car unsafe to drive and leaves me unemployed with a child and bills to take care of. Thank you Hyundai, nice job 👍🏻.