Check the bobbin case for a nick. Sometimes breaking a needle puts a burr on it which will make an awful sound. I had to have mine replaced on my 8200 (30 bucks for the part) after breaking a few needles.
But also try:
-rethreading your machine
-checking that there are no loose threads in the body of the machine
-vacuuming out the bobbin area if you have one of those tiny machine vacuums
-changing the needle
-making sure the bobbin is wound tight with no gaps
-looking in your manual for other troubleshooting ideas related to noise