Iave got a 2018 Hyundai Santa Fe Sport with a Theta II engine thatas failinga”burning oil way too fast, coolant mixing in the cylinders, and throwing a P0304 misfire code. Itas been undrivable since late April 2025, and Iam worried about safety because the misfire and engine failure risk could cause it to stall on the highway, putting me and others in danger. It shakes when I try to drive, which feels unsafe. A Hyundai dealer confirmed the issue, finding coolant in the cylinders and the misfire, with no visible oil leak. Oil change receipts show the oil disappearing over a few weeks. The manufacturer reviewed my case but denied the warranty claim, saying itas not covered since Iam a second owner and itas not a rod bearing issue, even though the 2021 Theta II settlement should apply to this. The seller didnat disclose the engineas defect history when I bought it in 2023. The check engine light came on in early April 2025 with the misfire code, and I noticed the oil issue then. Itall be out of service over 30 days by mid May 2025, so Iam taking legal action.