I listened to your video, but it's so short it was hard for me to pick up on the noise you're talking about. I think I may have heard two --- really high-pitched and almost "hissy", and another that wasn't constant, somewhat random, and much lower pitched. Was it one of those noises that you're concerned about?
A longer video - at least a minute - would be helpful.
A trick you can use: Take a long wooden rod (a cut-off section of broom handle works great). Put one end of it on various places on the engine and the other rounded end right up to your ear - touching. Keep moving around until you find the spot on the engine where the sound is obviously the loudest to figure out exactly where it's coming from. That should shed some light on things.