activeaqua airpump

the airpump has recently became louder, really loud. It sounds like somethings on the verge of rattling inside of it but not really rattling. before it was just a loud humming sound anybody else have this experience?

If it is like most that I have had it sounds like something is coming lose inside their should be 4 screws on the bottom take them out and you can have a good look inside depending on how many air out lets you have their should be a diaphram these operate with magnets and are on a little metal arms and the diaphrams are held on by nuts and bolts and in my experence the nuts come off and start to rattle around.

What type of pump? Diaphragm or Piston (commercial)