Is a MAK 4 supposed to be loud?

[RobbAdams]

Good day,

I have temporaraly hooked up my plumbing through a rubbermaid bid to check there are no leaks. So far so good. However the used Gen-X PCX40 is really loud. Is there any type of periodic service these things require? it sounds like a really loud refridgerator, the njoise is quite metallic.

I thought the reviews I read regarding this pump were that it is quiet? Are all big pumps loud?

Robb