Rattle Noise under load

It has a D16A9 engine (1.6L DOHC 130hp). I have it for about five months. I fixed a lot of stuff during this time, but this noise coming from the engine keeps annoying me. It is not a hard knock, but it is there. I can only hear it between 2000 and 3500 rpm and it has to be under acceleration/load. have checked the exhaust for leaks, checks heat shields and its none of that. I can hear it if i rev the car in neutral with or without the clutch pressed and of course when its in gear.
Hope someone can give me ideas of things to check.
I will leave a video so you guys can hear it.
https://www.youtube.com/watch?v=CG8wH9MOeCY
Thanks