Well heard this yesterday. Took the belt off to see if it was a pulley and nope. Do not hear it this morning when the engine is cold only starts once warmed up. Can hear it best from the rear of engine but that may be due to firewall reflecting sound. Also if I'm in park and shift to gear when the engine has load I cant hear it. Same if I turn on ac and there is load. Well just noticed barely can hear it. Pretty much disappears with some throttle in idle. Tried using a rod to pinpoint sound seems to be from passenger side. Uploading to youtube.
Any thoughts or similar experiences? Yes its nasty in there lol I've only had it a couple weeks. Mobile 1 0/40 with fleece change after I got it as well as air filters.

https://youtu.be/NhtwGTggGeY