growl/ errrr noise

[gravismaximus]

my hob filter whisper 30-60 has started making a noise and befor i try a new impeller i thought id ask if anyone else has heard this noise. its a errrr noise close to a rattle sound. it has somthing to do with the way the intake tube sits over the impeller because when you pick up on the intake tube, the sound goes away. but i dont see where the impeller is hitting into the tube. any ideas?

 

[forsfed50]

do you have a sand bottom

 

[tangs rule]

A tiny pebble/rock/carbon piece down inside the cavity where the impeller magnet sits can cause this. Remove the suction tube & impeller and use a turkey baster or pipette to remove all the water in the impeller cavity and get a light and look for a hard piece of junk down in there.....also can just remove the impeller and hose out cavity while holding unit upside down & flush it out. Check this 1st - there are other possible causes but this is the most likely.