If the needle is pinging, somehow it has either gotten bent or gotten a burr on it. There are any number of ways this can happen and it doesn't matter if you just put in a new one 5 minutes ago!
Just changing out the needle may take care of you loops as well. If not, then rethread your machine both top and bottom, making sure you have the bobbin in correctly and securely, and that you've tightened the new needle in securely as well.
Most likely this will take care of both the pinging and the loops.