Those look like the screws that are used to stabilize the washer or dryer drum during shipping. Typically you remove those screws when you set up the unit at your home. Then you store the screws so that you can stabilize it again if you move. Sometimes there are two screws, other times there are 4-6. It really depends on the model. They usually install in marked holes on the back of the unit.

Looks like whoever installed that unit stored the screws inside it for safe-keeping. I'm never that bright. Mine usually end up in a bag in a box behind several other boxes and tubs with other bags of parts and things that I'm sure I'm gonna need one day. Unlabeled of course.

You found some screws. You haven't found the source of your problem though.

As /u/metisdesigns/ notes, we can probably help if you supply the make and specific model of the unit. Take a picture of the tag and post it.