Hello Colleen,
If you want to hear what my machine sounds like when I'm doing FMQ on the 15K treadle, you can listen to it on Youtube- link to my channel below. Also, I use a hopping foot too, but mine is all metal.
If the stitching is good, I really wouldn't worry too much about the noise. Every machine is different, and if there were something wrong it wouldn't be stitching properly.