During the washing cycle there is a noise that sounds like something is "clicking" inside ( kind like washing something made of metal inside the drum). it is steady and lasts through the whole washing time. i wonder if some part needs to be replaced or something is loose? thanks!

I would suspect that something is caught between the inner and outer drum, like a bra wire or something similar.
If it washes and spins o/k, then I don't think it is a fault with the washer.
It will probably break up, or find it's way into the pump filter.
Hope this helps.

Washing machine bags when on a big spin