Actually that video has the serp belt removed. I noticed the serp tensioner pulley needs replaced before I slapped it back together. I was hoping maybe I would get lucky and that would be the problem, but no luck. I wanted to make sure it works before I replaced that.

I don't have a mechanics stethoscope but I did try a similar thing with a long screwdriver earlier. I can't hear the noise when I touch it to the valve cover at all. I also poked my head underneath to see if I could hear it from the oil pan and nothing. The only place I can really hear it is through the screw driver is on intake side poking around the fuel rail, but it's not really that loud there either.

I looked in through the passenger wheel well to see if something might be knocking outside the engine but didn't see anything. The only thing I did notice was that it reeked of exhaust in there. That made me think exhaust leak, but it just sounds so metallic.

I guess my next step is to pull the timing cover off again and make sure everything is tightened and not knocking there.