I am getting used to my new 06 3500. I wanted to ask if this is a common sound with the Cummins?
Pulling away from a light at a slower speed the engine sounds noisy, but put your foot into it a bit more and the diesel cackle quiets out as it accelerates. What causes the engine quiet down as you accelerate harder?

 

I think what you are hearing is the combustion during the early acceleration when the engine is working hard to move the heavy truck. It does get quieter as you accelerate as it doesn't have to work as hard to do so...

Mine does the same thing.

 

a major power plant just makes noise,

i think the noise is sweet music,

You really would not have liked the noise that my old chevy with 350 engine made.
as the tappets were clicking away, each time you took off.

 

It is much noiser then it almost seems like something redirects the diesel noise. I don't know if it has anything to do with the turbo kicking it or not.

Jb

 

You should record an audio track and post it in here... we'll have a better idea of what you are hearing that way.

 

my truck does the same thing and it is something I have found to be normal on my work trucks, and friends cummins motors too. I agree with maxwell!