Ok now you've explained I can hear it faintly. Can you get a closer clearer vid? Knock knock knock noises are definitely not good and usually related to the bottom end of the engine.

Does it do it when cold or just when warm?

Also when the engine is on the run down and coming off the revs this sounds like little end issues although this isn't what I'd call common on these engines.

There's also the infamous chain guide noises that sound like this...

https://www.youtube.com/watch?v=mZFX-T9hsFE