Hi Scotty I have a 2013 Hyundai Elantra Limited automatic transmission I bought in 2018 with 52k miles. It now has 75k miles and EVERY time I push on the gas I hear a rattle from the engine when the RPM hits 2250. It happens always but then goes away if the RPMs go above 2250. It doesn't make the noise if I don't get the RPMs to 2250. I have changed the oil every 5k miles since I got it. I recently noticed a valve cover oil leak and changed the gasket with a felpro and I applied gasket maker at the 2 spots indicated for it in the Haynes manual. No codes based off my bluedriver code reader. Also, it sometimes has a rough idle but not always where it shutters and the rpm drops to about 600 then comes right back up and it settles down. Long term fuel trim at idle is 11% and short term fuel trim is 0%. I use chevron fuel cleaner after oil changes and use 91 gas from shell. Much appreciated and thanks.