MAXXO6

Hey AudiWorld,

I just did a some work to my 2000 A6 2.7T/6-spd details are in my other thread:

https://www.audiworld.com/forums/a6-...-cels-2885846/

No CEL's now, but I am getting inconsistent boost/power with a bucking or shuttering sensation. It happens all threw acceleration, less at WOT, followed by bigger "buck" transitioning between accelerating and decelerating. Just put the N75 and N249 in, replaced a lot of the vacuum connectors and checked lines. I am a little stuck here not sure where to go next or what to check. I really could use an outside perspective!
Thank you very much!

georgeb944

Sounds like a vacuum/boost leak. Build an intake pressure tester and check for leaks. Any boost leak is a BAD THING!

Here is the link for building your own tester...

http://www.awe-tuning.com/media/pdf/...ure_tester.pdf

MAXXO6

Thank you Georgeb944!

I also noticed the vacuum line for the fuel pressure regulator was in rough shape. Replaced it and have had a good amount of power improvement. Car still feels like it's "held back" and small shuttering on hills.

I will pick up a fuel filter, do a fuel pressure test, and build the intake pressure tester throughout the week! I'll let you all know how its going once I get some more time into it.

I have questions on the pressure test. Once I put the system to 15 psi will it hold pressure or blow threw? Also can I spray everything with soapy water for leaks? I'm hard of hearing. Finally is there a walk threw on doing a vacuum test for all the vacuum lines related to the turbos or will the intake pressure test pressurize all those as well?

Thank you all for your help!

georgeb944

If you use the adapter as described, it will try to hold the pressure at 15 psi, since no cylinder has both valves open at the same time. Using soapy water to detect leakage is much better than trying to identify where it is hissing from.

It won't check all of the vacuum lines, but will take care of the most likely culprits.

SloopJohnB@mac.com

Make a smoke tester to go with your pressure tester. I hope you're not blind as well as hard of hearing.
No Helen Keller jokes here!

MAXXO6

Built the intake pressure tester and tried it out last night. Turns out the throttle body "Y" boot has a big split in it. Thank you Georgeb944 and SloopJohnB for your help! Feeling pretty dumb for missing that but the part is on order and my temporary fix on the old boot seems to have brought the old girl to life. Ill keep you posted on test after boot replacement.

johnkk

Was just going to emphasize the need to do the boost test, since I was having similar symptoms and the FPR vacuum hose had decayed as well. Both diverter valves were shot and I had a split at the throttle body on the Y hose hidden by the clamp. Pressure test hiss at the throttle body id'd the issue immediately.

Went for the silicone Y hose with substantial clamps and 710p versions of the diverter valves. Fully sorted and holding chipped boost. Had forgotten how fast she was! Now motivated to do a full polish and wax.