I have this Aqeuon 1250 powerhead, got it used. When I first put it in the tank, it was quite. However starting about 2 hours ago, it started making a little grinding sound. Its not constant, and its not terrible loud. But is some what noticeable. Is this a sign of it going out, should I replace the powerhead, or can I replace a part, does it just need a good cleaning?

Any help appreciated as always.