Fan Rattle help

[Pokesaurus]

My fan is rattles but when I put my hand in front of the fan it stops?

https://www.youtube.com/watch?v=edcWDJpxbrg

Is this an airflow/setup problem or is it a fan problem

 

[Nine Layer Nige]

Possibly the fan bearings have worn and the fan tips are hitting the mountings or grill. Placing your hand in front of it upsets the airflow and reduces the pressure which might reduce the forces involved so it stops hitting the tips.
That looks like a fan on a radiator...which way(direction and rotation) is it spinning ?

 

[Pokesaurus]

Possibly the fan bearings have worn and the fan tips are hitting the mountings or grill. Placing your hand in front of it upsets the airflow and reduces the pressure which might reduce the forces involved so it stops hitting the tips.
That looks like a fan on a radiator...which way(direction and rotation) is it spinning ?

The fan is spinning counterclockwise

 

[Nine Layer Nige]

Yeah, sounds like the bearings have worn. Possibly time for a new fan.