(problem resolved) with SWC 120 cone skimmer

I just purchased a 120 swc cone skimmer about a month ago and to start it was running great and was so quiet i couldn't hear it running. well last night i noticed my tank sounded really loud. long story short it was the skimmer.
i played with it and noticed if i turn the air off the vibration noise/thumping stops. but as soon as i add air its as loud as can be. i have it out of the sump now and am cleaning it , but thats not working. now what?
has anyone heard of this what could be the problem?

any insight on this would be appreciated

 

Have you looked inside the pump? It could be a small shell or piece of sand in the impeller.

 

yes i have it completely apart. this noise is only when i add the air. i have it in a bucket running without the main body on it. as soon as i attach the air line the pumps gets very loud.

 

Is the airline and silencer clear of debris?

 

yes i even pushed the air line under water and ran it under water than blow threw it. it sounds like the impellers not spinning properly. reminds me of a bad bearing sound. but i dont feel its the pump because when i take the air away the sound stops. and it sounds quiet like when i first installed it.
the impeller feels sloppy but im not sure if thats normal

i want to clarify i did take the pump apart and clean it. this hasnt made a difference. i dont think i was clear on that question you asked. this has me stumped

 

I'm a little stumped also. I'll pull a pump apart and take a look at what it could be. I'll get back to you later today.

 

here is what it sounds like. underwater my phone will only pick up the water splashing noise. but this sound is whats so loud... click the picture to run video.

 

i took it apart and cleaned the pump out looked at every piece and cleaned everything and still this noise.

 

i cant help at all..but it sounds like the impellor is loose somehow and is rattling against the sides... but im gonna give u a bump..good luck with the problem..

 

thanks. i do think it has to do with the impeller also. when i run it ran and watched it spin it actually looks like its stopping like its hitting on something. i cant figure it out. there nothing for it to hit on. its all cleaned out. i wonder is the impeller defective? or the pump?