Welcome to the world of timing chains. The chain is good for ????? miles depending on service history and the weakest link. I personally replace the chains at 100K intervals and I use only the dealer chain. It cost more, but I think it is worth the peace of mind. While you are in there also check;
Chain tensioning rail for being off center of the chain tensioner pin - replace if not aligned and replace the rail pin that holds it in place. You can check this by visually looking at the end of the tensioner and seeing the wear marks, are they centered on the pin??
Replace the tensioner spring. Under tension it bends to one side and rubs the housing and wears. Cheap enough.
The actual job isn't too hard, just have to be sure not to get out of time. Also new chains require a special crimper to install the last link. If you do try it yourself, get a manual and double check yourself.
Cost around 3-3 1/2 hours labor plus parts for chain alone.