Just noticed it all of a sudden. Here is a short video of the noise. It appears to come from the left side of the engine block on the passenger side. Happened on the drive home after a second gear pull and unfortunately had to go home like this.

My guess is a bad/loose belt or tensioner.

Any ideas what you think it could be?

 

If it were my car, I would remove the accessory belt and start the car up for a moment to see if the noise returns. It won't hurt the car if you run it for a few moments without an accessory belt. If it's not something running on the belt, then I would look for things that aren't bolted or maybe missing a mounting bolt, it sounds like metal vibrating. If still not able to locate it, then remove the upper and lower plastic timing covers and see if there's something making noise in there. Keep using the process of elimination.

 

Thanks ended up being the tensioner pulley. Replaced it and the noise went away.