Combine hamburger, onion, salt and oatmeal. Add milk as needed for hamburger mixture to hold shape. Make 3/4 - 1 inch meatballs with all of mixture. Place in oven safe casserole dish (I use throw away pans because the BBQ sauce can be hard to get off.).
Mix vinegar, sugar, water, ketchup and Worcestershire sauce.
Pour mixture over meatballs.
Bake in oven at 375°F for 15 - 20 minutes. Reduce heat to 350°F for 70 - 75 minutes.
Start cooking egg noodles about 30 minutes before meatballs are done. Serve meatballs over noodles.