i have an 03 A4 1.8T with an apr stage 1 chip. for the past year the turbo has been acting up and im losing hair over it. it will boost then drop off then boost up again then drop off very quickly and it usually happens during third fourth and fifth gear. i installed a boost gauge and when it acts up the pressure will rise to about 20-25 and then drop off the 5 then back up and down etc. i dont know if the diverter valve is bad or if it is something else considering that the problem started before i had it chipped. it works fine when its cold but as soon as it warms up the turbo acts up. any suggestions please!!!!!!!

 

most likely dv. check it first

 

alright thanks i definetely will check it. if the dv is bad any suggestions for a new one. should i keep it stock or should i go aftermarket(APR,AWE) cause it is chipped?

 

I have a Baileys. It has never failed me and it holds nice and strong.

 

if your chipped arent you supposed to change the DV anyway?

 

thats ur problem man... ur suppose to change the dv when u get chipped... but then again u said it was acting up before u got chipped... hmmm dont know

 

Baileys +1 great and no rubber dirafram like in the forge

 

i have the same problem and i am not chipped...could it be the waste gate spring is stuck open and the turbo is boosting irregularly or something like that...i have a stock dv and the boost goes so high up that the dv cant hold it and the turbo stalls all the time...

 

Your overboosting and causeing the car to hit limp. You need some form of boost control. You need to keep the boost under 23psi. Above that you can hit limp unless you install a 4.7v diode

 

We haven't manufactured a diaphragm valve for the VW/Audis in two years.