It's hard to tell, but I'm pretty sure it's around the bobbin. It still sews every pattern just fine and reverses just fine as well so I'm not really sure why it makes that sound but I wanted whoever buys it to be aware of it.
If you have any questions please feel free to let me know. This item is in the category "Crafts\Sewing\Sewing Machines & Sergers". The seller is "bibow4059" and is located in this country: US. This item can be shipped to United States.