Fluval 205 making noises / not working?

[Jeox]

My fluval 205 just makes this spinning / grinding noise when its on, but it won't work properly...Any ideas? This just suddenly happened.
Nothing is caught in the impeller.

 

[hmt321]

check your impeller spacer,

the shaft of the impeller usually has a rubber thing on the end that will give the impeller blades proper spacing to keep them off the sides of the shaft as it spins, if this rubber spacer is off or missing, it will make a grinding noise.

 

[turbid]

or maybe the impellor got 'unglued' (sorry cant find a better word) from the magnet

 

[ziggy2]

I can only be the impeller.