engine clacking?

so i had my TLS for almost 6 months now there is this weird clacking by the pullys but i cant figure out what it is, after months of research it looks like it could be the Harmonic balancer AKA Crank Pully that needs replacing? i check the Alternator, AC compressor, idle pully/tensioner and brand new drive belt all is good.

anyone experiencing similar issues or know what this is?

video is at above link

thanks.