Get out your nutdrivers and take the sheet metal cover off. You should be able to figure out what it is that's making noise. It might be a loose cover or a couple missing sheet metal screws.
I wouldn't know.
Shut it off and have a pro check it out. Sounds like it is short cycling to me. It doesn't run long enough to remove much humidity. It will cool but it will be clammy. If your humidity inside your house isn't 50% or lower it isn't running long enough. Many contractors install too big of unit and that's what it does.
That's what I heard/read.
