Jeep sounded pretty nasty, and it kept getting worse. I eventually noticed that the fan was making contact with the plastic shroud. I spent some time planning out how to lower the shroud, before I finally thought "why did the fan move"? It turns out that my 11 year old engine mounts had finally given out. About $35 later, I've got new rubber bushings for my Brown Dog mounts, and I'm back in business.