I recently installed a boost guage only to find out that I'm not getting the boost that I should. I have a GIAC chipper '01 A4...so I should be seeing around 14 psi of boost. Right now I'm getting ~20 in Hg of vacuum and 3-4 psi of boost.

Boost leak or bad DV, right? I'm going to be changing the timing belt this wekend and will check the post turbo portion of the intake system from top to bottom. Besides the vacuum line coming off the DV, what other vacuum lines have caused people problems? Has anyone had any of the big hoses develop leaks? From what I've read, most people find their leaks at a vacuum line. There are so many vacuum lines under the hood that I was hoping you guys could point me to some likely culprits.

I have upgraded the DV to the Turbo XS adjustable valve. I have tried putting in the packing washers to increase the spring tension with no results. I have contacted Turbo XS to see about getting another (stiffer) spring. If I don't find any leaks this weekend I'm going to throw away that DV and get another one.

 

where did u get it chipped bc u might have been ripped off. always send to giac themselves if u didnt. u didnt mess with anything that would really cause that much boost lost. ur just boosting stock. open ur ecy and look at the chip and post a pic well all be able to tell whether it is real

 

^^^^^No you wont, the chips dont all look the same, alot look just like a stock chip....

 

well the boost guage dont lie in other senses

 

When your boosting... does it sound like the turbo is blowing onto the ground?

 

I got my chip from AWE Tuning. I'm sure it's a real Garrett (GIAC) chip but, I will get the chip checked out to make sure everything is operating like it should be. I got the chip almost 9 months ago. I noticed a big performance difference at the beginning but like everyone else I gradually got used to it and therefore didn't notice the performance drop off.

There are no rushing air noises that I can hear over the sound of the engine. Anyone have any suggested locations to pay extra attention to when I go to inspect for leaks?

 

yeah 3 - 4 psi is less than stock... so you've got something wrong. dealers can do some crazy smoke thing, to find boost leaks.

 

I checked for leaks this weekend and didn't find any. I'm setting up a time to get to a friends shop to use his VAG-COM setup (and more importantly his experience) to see if I can figure out what is wrong. I'll keep you guys up to date.

 

I got this code from VAG-COM:
17956 - Boost Pressure Regulation Valve (N75): Open Circuit
P1548 - 35-00 - -

Does it mean that the N75 valve is bad or just misbehaving?

 

Sometimes the the powerline to the N75 valve gets loose or cracked.
Check that before replacing it.