I agree with 1.41. Not all that long ago I pulled out a toothpick from a motor.
Also, if you haven't already done so, disconnect the motor from the machine and run the motor, does it make the same noises? If so, then I would take it apart. If not, maybe there's something in the machine making noise (although I did just take apart a Singer motor which rattled while spinning up under load, but didn't make any noise disconnected, taking it apart and cleaning it fixed the rattle).