Ok, so I finally did my first boost leak test on my 2001 Audi A6 2.7T Quattro with APB engine FAQ tip transmission.
It wont hold any pressure, it seems like the pressure is escaping from the driver side intake pipe, between the 2 metal pipes, which makes sense because how are 2 metal pipes supposed to form a good seal? What do I do about this?

Also I capped the little part on the Y-pipe which goes to the pancake thingy and some of the pressure was coming out of the pancake thingy so I removed the cap and plugged the pancake thingy back in and it wasn't coming out at much from there anymore.... What do I do about that?

 

Will someone please help me out with this? The 2 metal pipes that I'm talking about are the ones that are right after the rubber hose that connects the y-pipe to the diverter valves, it goes down the side of the engine into another metal pipe that goes to the turbo... Should there be an o-ring there or something (seems dangerous to have an o-ring there since if anything it could get sucked into the turbo, no?)??? help please...

am I supposed to do anything with the n75 valve hoses or any other hoses when I do the boost leak test? should I have my oil cap off?

 

Is the car holding any boost? If its just spooling and no boost its most likely a faulty n75.

Also I would post this on the audizine b5 s4 section. Those guys are on 24/7 and will give you a precise answer.

 

It seems like the boost is fine. I've been searching like crazy about boost leak testing on the 2.7T and there is very little detail to EXACTLY how to do it and what to do in certain situations. I've read that air can leak from the atmospheric pressure areas and that it will not effect boost, but it did say that it will lead to premature turbo failure, bad engine oil and premature engine failure...