boost/vacuume leak issue

[B5//S4]

Ok guys, I am finally breaking down and posting my issue. I have searched and read as much as I can handle at this point.

Now, first let me explain my car and mods. I have a 2001.5 TIP. I have a custom VAST tune for a stock set up, ie. turbos exhaust ect. But I have Evolution Motorsports DV's. The tune is very aggressive! Pretty much maxing out the turbos and injectors and everything else. Boost peaks at 20-21psi then tapers to about 18psi. Great tune by the way, pulls insane for just having a tune and being a TIP!(L box ecu with vast tune for sale fyi)

My driver side turbo started to whine like a supercharger once above 5psi or so. With the turbo whining, it has boosted normal, pulled normal, seemed like there was no problem. Just was like I swapped my turbos for a easton blower...?? Whatever. On a side note, I have been seeing oil under my S on the driver side. Nothing serious, just some spotting...my car is a she by the way.. I also have noticed a modest amount of oil on the turbo outlet pipe, long before the turbo started singing. I figured it was just a small valve cover gasket leak dripping on the turbo, and would take care of it soon enough.

Now on to the issue. 2 weeks ago I have noticed a few new things.
1) During high boost I hear a loud sound that I would describe as rushing air. It almost takes over the loud supercharger like noise. It is also combined with a high pitched squeal. After 1 maybe 2 seconds of this sound the boost cuts down to 5psi and never goes above untill I shut the car down and restart.
2) When I let off of the gas there is a very high pitched noise. Like when slowly letting air out of a balloon. This noise is constant as long as the motor is in vacuum, or just the slightest amount of load on the motor, when pressing the gas. It also makes this noise when stoped or idle but tends to stop sometimes after sitting for a moment.

I have not had time to pressure test or pull any codes since this started. But I have planed some time over the weekend to do this. I am at work right now and cant stop thinking about what is causing these two new issues. Like I stated at the beginning, I have searched and searched looking for anything that might point me in the right direction.

Forgive the length and detail of this post. But, I felt it to be necessary in order to receive the best response and help needed from you more experienced AZ members.
Thanks to all who help,
-T-

[DRA4]

Sounds like the driver side turbo is on is way out. 21psi is a lot for K03s, pulls hard but you are killing them.

[B5//S4]

I know the turbo is on its way out. I know that 21psi is allot for k03s's. My concern is with the (2) new noises that started 2 weeks ago. My turbo has been howling for 2 months now.
However, if what you are saying is that the turbo is on its way out(about to blow) and that the noises and boost cut that I am now experiencing is do to the turbo. Than that is what I needed to know, and thank you.
From the new noises I hear I have been thinking 'boost leak'. and the squealing noise when I get off the throttle and in vacuum is driving me crazy! Not only the noise but driving me crazy trying to think what would be making that noise.
Thanks for your input DRA4. By the way, your 'choped' lowered santorin looks great! And I like the red time attack stripe on the wheels, nice touch.

[DRA4]

No problem dude, my is having problems with the freaking maf. Had to unplug the damn thing to make it home last night but with no boost at all. Is back in the shop but i love my car lol. My turbos whine like crazy too and is the driver side, i just learn to live with it and try to save for K04s. I would do a pressure test asap on it, heck i have to do one on mine too. Thanks about my car, is finally getting drop this week.

[B5//S4]

That suck about you MAF! Hope you figure it out. Ya i dont care about my turbos going. Ive been fine with the loud ass turbo lady and still boosting fine, but this new issue is getting the best of me! Im so close to just pulling my motor and doing tial 605's and every maintenance thing I can think of! And I just might this weekend having set things aside to work on my S anyway...But good thing I have a wife that keeps me in check so I don't go dig into our savings and blow 30g's on making my S a deadly street monster!! but I want to sooo bad!!!!
Oh boy, look what ive done, way off topic....Thanks DRA4!
Shoot me some pics when you get your drop! or even better post them up in the santorin pic thread! That thing has seen less action then...I cant think of a good zinger..

[obijohn22]

no one here can help you without codes and a good pressure test. we want to help, but without those pieces of the puzzle there is nothing we can do. sounds like the TBB to me or maybe the DV's, some kind of massive boost leak... you're hitting limp mode so.... get back to us with the results of the test and pull codes.

[DRA4]

That suck about you MAF! Hope you figure it out. Ya i dont care about my turbos going. Ive been fine with the loud ass turbo lady and still boosting fine, but this new issue is getting the best of me! Im so close to just pulling my motor and doing tial 605's and every maintenance thing I can think of! And I just might this weekend having set things aside to work on my S anyway...But good thing I have a wife that keeps me in check so I don't go dig into our savings and blow 30g's on making my S a deadly street monster!! but I want to sooo bad!!!!
Oh boy, look what ive done, way off topic....Thanks DRA4!


Shoot me some pics when you get your drop! or even better post them up in the santorin pic thread! That thing has seen less action then...I cant think of a good zinger..

lol totally understand you man, keep your head up. I sure will post pics when is drop from before and after. Like obijohn22 said, do a pressure test, codes and then post it. Good luck with it and enjoy it.

[Audiophyle]

A large enough boost leak will be very audible, and the car is going into limp mode because of one.

Running with a leak is very hard on the turbos, and can kill them even faster by allowing them to overspool.
20~21psi is way high for these tiny turbos, and with a leak they have to spin even faster to compensate for that loss of pressure. (which = even harder on the turbos)

Get that leak fixed pronto, it is not a sign of a dying turbo, but it will result in a dead turbo if left alone.

[B5//S4]

Thanks for your input everyone. You guys are great. I agree that I need to get some codes before you all can help me more, I just havent had time to, and have had enough of thinkining about what might be going on. So I posted with hopes of someone having the same experience as myself. I havent had time to pressure test today, but I did pull codes. I have yet to research them and I wont have time to really dig in till the weekend. Anyway, here are the codes. Have at it you guys. I look forward to reading what you all have to say about them!
17819
17831
17865
17544
17546
17956
17539
17956
Thanks again guys!

[agentsmith988]

Thanks for your input everyone. You guys are great. I agree that I need to get some codes before you all can help me more, I just havent had time to, and have had enough of thinkining about what might be going on. So I posted with hopes of someone having the same experience as myself. I havent had time to pressure test today, but I did pull codes. I have yet to research them and I wont have time to really dig in till the weekend. Anyway, here are the codes. Have at it you guys. I look forward to reading what you all have to say about them!
17819
17831
17865
17544
17546
17956
17539
17956
Thanks again guys!

From a quick glance, looks like you need to look into givin' some love to your O2 sensors and N75.

Also, good to see another Utah guy on here. Did you buy your car modded the way it is? If so, I think I met the previous owner the other day.

[B5//S4]

From a quick glance, looks like you need to look into givin' some love to your O2 sensors and N75.

Also, good to see another Utah guy on here. Did you buy your car modded the way it is? If so, I think I met the previous owner the other day.

Ya, 02's need major love! N75 fault is due to not having one. I run an electronic boost controller with my vast tune. And no, I bought my car 100% stock. Fishbowl windows and all. So you met someone who had a Santorin S that looked like mine?? Ya, we need more B5 S4's from Utah to come out of the wood works. I know 3 guys with S's around here. Two with rs6's. And one is a good friend of mine who's S is well...Like none other ever seen, even the most insane builds posted on AZ have never seen the likes of this. Anyway, do you know many around here? I want to start a B5 S4 club in Utah...Anyway, thanks for your input.

[agentsmith988]

I was up in Draper getting my filler plate painted, and an employee started telling me about his S he sold awhile back, described kind of the same look as yours. But nope, I don't know anyone around here yet. Just moved here a few months back. It'd be sweet to get a better community out here! If you ever need a hand or vagcom, I'm happy to help!

[B5//S4]

I was up in Draper getting my filler plate painted, and an employee started telling me about his S he sold awhile back, described kind of the same look as yours. But nope, I don't know anyone around here yet. Just moved here a few months back. It'd be sweet to get a better community out here! If you ever need a hand or vagcom, I'm happy to help!

Cool man I just might take you up on that offer, likewise if you need help with something. I have vagcom, well ebay cable and registered vcds lite. works pretty good.
Hit me up if you ever want to hang or go on a cruise.

Back on topic..
I couldnt sleep last night so I dicked around with my car a bit more at ohh...3am the witching hour...and the squealing noise after I let off the gas I can hear coming almost directly under the Y pipe. At first I thought it was the Y fitting coming off the waste gate lines to the N75. So I checked those out really good and couldn't find anything out of the ordinary. So listening a bit better where the noise is coming from it seems to be under the Y pipe. But Im not 100% on that location.
I know I just need to pressure test it, and I will this weekend. I just wanted to share what I had looked into this morning and post about it. Sometimes it helps to just talk things over to get the mind going...
Thanks again everyone for helping out.