I've researched this topic, so i know that the a4 2.0t engine is rougher than some other engines. However, my a4's engine seems to be particularly rough around 1500-1600 rpm's. It is a noticeable difference from higher rpm's. i don't mean roughness in motion but in noise. I'm not sure how to describe it other than that i've heard other engines sound like that but they are usually big rough engines. Any ideas as to what it was. A couple months ago, i took it to the dealer when the check engine light came on. They found that a piston in the fuel pump was sticking so they changed it, the camshaft, and pretty much everything connected. It smoothed out, but i noticed this sound a couple days later after pushing the car into the 5400 rpm range for a minute or two. would this be the normal roughness of the engine that i just never noticed before or could it be a problem?

 

I would imagine if you never noticed it before that's probably because it wasn't there... unless it's fairly subtle and you are just listening for it more now.

I know mine is kind of throaty (not exhaust loud throaty, though) at low RPM, low speed.

 

It could be a sticking intake flap motor, i hope they did the high pressure fuel pump and intake camshaft install correctly too.