SO i just picked up an 07 a4 2.0t(45k)....lets just say it has no power its pathetic when your room mates 87 corolla can out accelerate and top out faster than my car. i knew the car had problems now i am trying to narrow down them.

I checked DV and its the new type with plastic diaphram
I checked all the intercooler and pipes everyhting is clamped and ok
I pressured checked the system no leaks that i can hear

SO then i checked the oil cap for suction while the car was on, and well the engine sucked the cap right back down, a tech from audi said you need to replace the pcv, so i did, not only did it not make a power difference the oil cap stills gets sucked down!

And i am throwing a p0229 code( turbo underboost) ya and i cant hear the turbo at all

I have read so much and searched so much I am trying everything and help is very appreciated ! 45k miles on it

 

First off if you have a diaphram in your DV it is not the newer one. The best one has a Piston in there. Diaphrams tear easily.

2nd coils are a big issue. read my stickey up top.

 

Ok I will check the coils,( I do not hear, see or feel a miss which can be pretty noticeable on a i4) when I installed the new pcv there was no oil or residue on the top of the engine what so ever, and the diaphragm i am not 100%, but when I took it Audi tech
( gave me an undertable quick diagnostic) he checked the dv and said it had been replaced with new updated one, said it look good. I will check my self this weekend to see what type of dv was installed. Thanks for the info!

And if a sensor/valve is bad would you still be able to hear turbo? I hear no whistle, wind, grinding nothing from the turbo.

I am going to do a compression check as well just to see if there's a possible head gasket issue.

 

So I was messin around and the wastegate does absolutlely does not move so(when engine is runing) I checked the vacuum line coming off it that goes to the electrical valve/actuator ( I broke the plastic nipple off of it f@&$!)

The wastegate did move when I moved not sure if I should have but I did,
So what's that actuator/valve called? And is my turbo garbage?

I'm still searching other post but not getting similar problems as I am, and input and help is very appreciated!