3.6 Pentastar Rattling

Could be the roller lifters on the 3.6. Those are notorious for going bad. If left they take out the camshafts. Unfortunately pretty common on those. Changing the lifters isn't too bad, done it myself. But changing the cams is a new level because of the timing chains. I think they make a tool to hold the phasers in place and allow you to remove the cam.