8.1 louder than duramax

[2002 Indigo Blue]

My 8.1 sounds like a cummins when I start it up in the mornings (sounds like it may be lifters)Even after it sits for only 15 min it makes alot of noise at start up.It gets louder when I let off the gas.Truck has 32000 miles on it now but the noise started around 2500 miles ago.Needs to go to the stealer with a whole list of problems:
engine noise,steering rattle(still),CD player making a whining noise,rear leafspring pads,weather striping missing between front & rear doors on drivers side,check engine light comes & goes.Love the truck,just wondering if the dealer is going to say that's normal engine noise even though it recently started. thanks guys

[JB 2500HD CC]

When you say leaf spring pads...what do you mean...I complained to the my dealer about a strange noise coming from the back. They lubed the springs and it went away for a while, yet the sound is back.

What should they be looking for?

Thanks.

[6600Duramax]

I believe there are suppose to be spring rubbers on the next to bottom leaf were the overloads hit. I alos heard this noise for several weeks and finally slid underneath and had someone bonce on the back bumper. This is my problem, now I have to get to dealer before out of warranty. This wouldn't be a hard do yourself fix, bu tI cannot think of what to put on the spring that wont wither bonce off or rub thru?

Dealer problem for me.