The beginning of your sound sounds exactly like the lens cover opening on the Epson 30x0 and 50x0 models... but yours does not have that.......
This should be an auto-iris issue. Google "epson 8350 grinding" and you will see a lot of people have had this issue before with your model.
This should be an auto-iris issue. Google "epson 8350 grinding" and you will see a lot of people have had this issue before with your model.