sounds like you need to rethread-from the beginning & make sure your thread is between the tension disks correctly---nesting on the bottom is a top thread issue- sometimes it is easy to miss one simple step when threading- so rethreading should be the first (try)--you may have knocked something loose- done something when you cleaned it???look it over --- on my vintage singer the needle goes in with the flat side to the right???could the needle be in backwards? i don't know if that is even possible---but it sounds as if the threading may be the problem- also check to see if maybe a piece of lint is caught in the tension disks- that can cause the problem too-- when all else fails start over from the beginning. good luck!