On two separate occasions now I have been warming the engine when it died with a loud clunk, like something in the case hit something. On both occasions the engine was cold and had been idling for about a minute on half choke when I gave the throttle a little blip/twist. Now I know that sometimes a cold engine will bog and die while warming if you give it too much gas too quickly, so the engine dying is not my primary concern. But that bang is fairly worrisome. Has anyone else experienced this? This is a bone stock 07 XRL with all the smog stuff still intact and only about 60 miles.