Pumps do go bad. A really good pump will last about 4 years. I would personally not use it to fold till you can get a replacement pump. It could be catastrophic if the pump were to seize.
Originally Posted by ira-k
Sounds like you may have gotten a big air bubble stuck in it, unmount your pump if its bolted down and shake it real well and see if you can get any air out of it.
The only moving part in that pump is the impeller and it rides on a ceramic bead, so usually when the bead or more likely the metal saddle in the bottom of the impeller it rides on gets wallowed out it will make a scraping screechy kind of sound.