Thanks everyone

I tried plugging in just the motor without the pump. The shaft did not spin (but it did hum again). I unplugged it and tried one more time to confirm. Same thing although this time I did hear a grind/grumbling noise that lasted for a second or so.

As far as how loud it was when it was running, it's hard to say because I had nothing to compare it to. First time pool owner (just bought the house). However, I found it to be loud.

You guys called the white powder oxidation, and you're probably right, but it had crossed my mind that it might be DE. Possible?

So, I guess the conseses seems to be that I should just replace it. The motor itself I found for $180. The whole pump I found for $280. Being that it was suggested to replace some other parts too, I may just buy a whole new unit and save myself some headaches.

So, my only real question is, what happened here? Did this just get old and was time for relacement or was this used improperly, or maintained improperly? I just want to know so that it doesn't happen to my new one either.

Thanks a ton guys!