Mariamummy01, I have a serger, but not a Singer, and not used very often. When I have had problems with the thread not making loops properly when stitching it has been
because somehow a thread that goes to the Right or Left looper got out of one of its many thread guides. And as much as I hate to have to rethread a Serger, it might be
that is what you need to do. If you have already tried that and changed the needles, maybe look up a Singer Serger dealer and call or email them directly with a description
of the problem. When was the last time you had it in for service to be cleaned and check that all parts are functioning properly. Hope you get it fixed soon. HelenW