Cascade canister clicking noise

[BassetsForBrown]

Hi,
My cascade canister filter stalled....once I realized this I took it apart, and was able to get it going again. This morning I woke up to find it stalled once again. I took it apart, and after bumping it more times than I can count, it started again. However, it now makes a clicking/scraping noise while running.

What might be causing this, and what can I do about it? Id prefer not to buy a new canister if this one is salvageable. I looked at the impeller - it's not nicked or cracked, and the magnet attached it to looks fine too. I also measured it with a digital level and am positive it is sitting evenly.

Thanks for any help

 

[jonclark96]

Do you have sand substrate in your tank? Sounds like you may have some sand where the impeller sits in the motor housing.

 

[duanes]

It is not only the impeller that needs to be checked, as Jon said, if a grain of sand got into the impeller housing or the volute, it could have caused wear and erosion of the volute, enough to make the impeller wobble, which can cause a crackling sound (cavitation), and creates more wear. You may need a magnifying glass to notice damage (it can be small, yet significant).
I know the pump below is not a canister, but all centifugal pumps run on the same principle.
Note how the actual housing where the impeller shaft sat (spun) is worn in a sort of 8 formation. At the time I had used play sand as substrate, which got in and ruined the pump.

Before I noticed the wear in the housing, I had replaced the impeller, which quickly failed.