Grunt at start before 2nd Gear & Moan upon accelaration (06,TRD/OR,Auto,2wd)

I have had this truck since May and have always had this subtle grunt noise after shifting into D, before 2nd gear. Sounds like a truck electronically shifting into 4WD, but that is not possible with this 2WD

Do ya'll know what I'm talkin' about?

Additionally:

Upon gentle acceleration thru all gears I have a subtle moaning sound. If I give it heavier accelleration it's not as noticable. Seems to be torque converter related? Or is this drivetrain sound just normal?

Any insight is appreciated!

 

I have this same sound, mine was the plastic air intake where it goes into the fender. In the winter it contracts and moves around inside the fender. It took me 3 months to figure out. I put a piece of rubber in there, its now good to go.

Check your intake, see if it moves around where it enters fender.