I know that this is a VERY old thread, but I am wondering what the outcome was. Did you take it apart? Did it finally just fail? I am a brand new pool owner and my pump that was just installed less than 3 weeks ago just started making the exact same noise and then it tripped the breaker. I am very upset about this as we have only been able to swim for the past two days and now this. Any help would be greatly appreciated.