I recently purchaced a 2000 s4 2.7t. When taking off you can feel good power but it quickly fades as though it's losing the turbo boost. Is there any ideas????

 

do you hear any loud noises. Maybe theres a boost leak. Check ur hoses, DV's, TBB, and the f-hose if ur a manual.

 

No loud noises...I just notice a good pull and then sudden drop off....

 

Check the Throttle Body Boot for tears

 

I just went through this and I think I can safely say that you probably have a boost leak, most likely the throttle body boot as it is notorious for tearing. Do you feel a consistent, steady amount of acceleration, then it's feels like there's a flat spot in the power band where power just levels off, but if you give it more gas it picks back up again? For me, the flat spot was right around 2700 - 3000 RPM. Not sure if that's what you're seeing, but thats the problem I had and it was the TBB. Like a new car after replacing it.

Also, to confirm it, see if you can get on a street with a concrete barrier or something on the side of the street that will give the sound something to resonate off of. Open your windows and steadily accelerate, if you're lucky, you'll should be able to hear a hissing noise resonate off the concrete barrier when your power levels off, if you have a boost leak that is. Hope this helps.