I got my mustang Ecoboost yesterday and after some driving with the music on, I turned it off and realized that there was a noise coming from the engine.
that sounds almost exactly like rod knock(spun bearing/s)....does it make the noise around 2500rpms? if so most likely. if bought new i'd take it back, hopefully swap or something. If used, hopefully you still have warranty on it and if u can still take it back.
do check the oil level like above poster, maybe check if its got metal flakes(probably harder to see unless u remove the oil, but i'd just take it to the dealer)