Well, I would think that those signs are a little late to change the needle. The clunk in mine means the needle is bent or broken. When it is dull, the needle tends to pull threads in the fabric, or break threads in the fabric, but if you listen carefully, the motor labors a little harder and the needle makes a different noise as it hits the fabric when the needle is getting dull. Sometimes, I stop and feel the end of the needle to see if there is a tiny spur on the end. That happens to me when my needle is having problems. How about the rest of you?