When I rev the engine to around 2500 rpm or higher in park, I can feel some little vibration from the engine transmitted to the steering wheel. Is that normal? It also does the same thing while driving.

 

Not normal. Especially not for a new truck with a state of the art engine. Take it in to the dealer.

 

What is the purpose of revving it in park?

 

To see the vibration

 

Have you revved up to 5000? Does it vibrate?

 

Mine won't go past 4000 rpm when it's in park or neutral, as the ECU limits the throttle position. Wonderful nanny crap!

Some very minor vibration may be normal with no load on the engine. So are we talking about a small, just barely feel it through the wheel type vibration, or a making the dash rattle type?

 

It's just small vibration. It doesn't rattle the dash or anything.
I used to drive sedans it was all very smooth( this is my first truck). Maybe this vibration is normal for a truck?

 

The weird thing is that the vibration becomes even more noticeable when I'm driving in 4A mode

 

Just the typical vibrations ALL V6's have. Its the design of the V6 vs the V8.
They do not balance as well from what I recall. A 90D V8 can be made super smooth due to the way they fire and balance. The V6's just cant do that. Maybe someone can explain better. But I think its the design.

Mine too has a little vibration and feels like a slight miss at idle. have not tried 2500 rpms though....

 

The original GM (Buick) v6 in the 80's would stir your martini when it was running at its best. That was one rough-*** motor.