SH33SH

i haven't the slightest clue what the problem could be, but some of you seasoned veterans might be able to assist me. i changed the turbos, put on the rs4 intercoolers with apr silicone hoses as well. i bought the car as a project. it had blown turbos when i bought it. white smoke. always.. no smoke any longer at all. no oil use problems. i broke in the clutch first. so i was nice to the turbos off the bat for 500 miles. im baffled.

so, a little background. Any time im in 2nd gear or higher. the car gets to 20psi and immediately drops to 15 and tries to climb to 18psi. all the while it starts the whistle. it sounds like a boost leak. i know its not the turbos. checked them the other day by pulling the motor up and pulling the rs4 inlets. there was no shaft play vertical or horizontal, including fore and aft.

i need some more ideas.

i am guessing the car is chipped, since im seeing such high boost. obviously it isn't stage 3. but i know i can safely run the k04s.

BW 025/026
034 rs4 inlets
Rs4 intercoolers
SB OFE clutch
fidanza flywheel
"H" valve
hyperboost DV's
silicone TBB upgrade


first person to find out whats what with this darn issue gets something cool.... please help me.

SH33SH

i'd also like to mention that my boost gauge does not read a full -20 in Hg(vac)

i believe this may be an indicator as well where the problem may be stemming from, but once again have no idea where to look.

thanks in advance for any help at all.

csosnowski

Are you running K04's with a K03 tune and MAF?

Could be the ECU dumping massive amounts of boost its seeing from the larger turbos since it expects less boost less early in the rev band.

Ive contemplated throwing K04's on my Avant, and it was suggested to me to put a manual boost controller on to compensate for this and boost spikes.

SH33SH

I believe its a vacuum leak honestly. I know that with stage 1 tuning, or a stock mapped ecu that you can run k04's with no real world gain, so I don't believe that is the case. The fact that I'm not seeing -20 on the vac. Side of the gauge leads me to believe there is a vacuum leak. If it was a boost hose leak, it would most likely pop off and my car wouldn't run until I got the boost hose back on and tightened up. I'll keep the MBC in mind though, thanks for the reply.

Does my reasoning and logic seem to be in line here? Anyone please respond. Thanks in advance.

thejulex

Have you done boost leak test yet?

Quattrocket

You definitely need to do a boost system leak test first. You will drive yourself insane trying to find it without one.
Search around for some instructions on how to build a tool to test it.
I was in a similar situation to you and went nuts trying to find it, I tested it and found a clamp that wasn't fully tightened on one of the boost hoses coming from the turbo...
Good Luck!

highspeedS4

Are you throwing any codes? Boost test ftw. If the car is pulling fine then its probably a small leak somewhere, but if its stumbling you got a big one. Everything sounds like boost leak though

JMS-Four

"i am guessing the car is chipped, since im seeing such high boost. obviously it isn't stage 3. but i know i can safely run the k04s. "

ahem.


It will help to know. If you just threw on K04s and didn't update the software, or if the car isn't "chipped", your ecu could be seeing 20psi and saying "WTF is this?" Or, if you're running a stage 1 program and boosting to 20 psi on k04s, that could cause some issues.

Did you upgrade fueling at all?

20 psi on K04s is A LOT more air than 20 psi on K03s, since the volume of air being pushed is so much greater, so perhaps your fueling can't keep up with the boost.


Without knowing your fueling or software, and if you haven't tested for leaks, it's hard to say where to begin.

When I had a boost leak (TBB came off a bit), it didn't whistle.