2001 S80 T6

Right when I start driving it, if I cruise around 40mph (could be any speed), I can feel a slight hesitation, just barely rocking me forward in my seat, you can barely feel it.

After a couple of miles, the temp gauge gets to 50%, and it goes away completely.

Any ideas? I'm currently test driving the car deciding to buy it or not as I said in my other post.

Thanks for the help.

 

It could be many things.
Might need a tune up or software upgrade.

 

Could it be carbon build-up in the intake? someone mentioned that to me.

 

Maybe or dirty throttle body as well.