Originally Posted by abetz470

So it usually happens when i first start to drive the car. Around 35-40 mph when i am trying to hold the speed constant the rpm's will jump up and down 1k its usually when they are around 1600-1800 rpms. Not sure if that is just the turbo or what. It becomes really annoying because the engine is revving back and forth as it goes up and down rapidly. just bought the car last week 2008 A4 CPO 2.0. Any one have any ideas?

Originally Posted by Billy Sarber

I have the same issue with my 2006 a4 2.0t quattro and I was reading the comments and it clicked. I think there is a strong possibility that there is a hairline crack in one of the vacuum lines causing the fluctuation. I am going to replace them all and will give an update