I have 49k miles on my 05. Up till now she has been pretty smooth and quiet. However, at the last oil change, performed in 10k mile intervals, I noticed she was alot more metallic... getting nearer to a 2nd gen sound. What gives? I used the same oil as always (Rotella 15-40) and the standard mopar filter... what would cause this? I dont think its a real area for great concern, I just want to figure out why.

 

My guess is that you are getting some miles on her now and she is finally broke-in good. Mine has become louder too with more miles.

 

Not to be an alarmist but you may also want to check out the UOA posted on the front page here from the guy who went 10K miles on Rotella 5w-40 and had pretty elevated wear metals. It wouldn't hurt to run one once and see where you are at vs. where you should be. Mine too has gotten louder with miles, however, but doesn't have the traditional clattery-bang sound the older Cummins engines had.