Hissing during boost

[A4 KiDD 810]

Hey, I just got flashed last thursday, but something happened friday, and I just got the car back this thursday. Anyway, Today on the way up to a local meet, I noticed a pretty noticable hissing if i'm flooring it or mostly flooring it, and i'm past 3k rpm. My friend said its just the turbo spooling alot louder now since the flash, but I have my worries that maybe a hose came loose of the DV or there is possibly a boost leak somewhere causing that sound. Is it normal? I dont really remember hearing that kind of hissing on other people's cars that were chipped. I dont have a boost gauge yet so yea I know thats the 1st part of the problem, so Idk what I'm boosting and if I'm at full power or not. Thanks for the comments.

[Carlitos]

boost leak test...


you are suppose to hear the k03, but not THAT loud.

[EYE4SPEED]

X2 after my GIAC flash and APR exhaust install... At first, thought it was a loose connection from the cat to the dp, but sound is only on hard throttle. Do have a Forge DV going in soon...

[b6onboost]

Getting chipped will make the turbo spool more audible, but its a high pitched noise like a wistle. If it just sounds like 'hissing' you probably have a boost leak. Check all hoses and connections.

[A4 KiDD 810]

I mean maybe it has something to do with the DV cuz when I had the stock DV in before I lost the car for a week, I drove about 60-70 miles on it and heard no hissing at all in boost, now I have a Bailey Motorsports on and its just hissing after 3k. Idk i dont feel like dealing with this shit right now its been such a long day and a long week waiting to get my car back from repairs i cant even think of sending it back in.

[quat]

Have you noticed a power loss?

[A4 KiDD 810]

There could be a small power loss, actually now that I think of it I'm gonna go with yes, since I noticed a little bit that my 2nd and 3rd gear pulls were a little weak. So how much is this one gonna cost me ?

[quat]

my bet is a boost leak. run a test. find out where you are leaking and then someone can tell you how much

[vinny.dtw]

Get a boost gauge so you can regulate this regularly. But like everyone says, check for a boost leak.

[JeffAhn]

boost leak - also good to change that DV valve

[Exanimas]

I got flashed recently too and noticed an increase in sound at 3K+ too. I'm pretty sure it's the turbo spooling. It's much more audible than stock, but I wouldn't exactly describe it as hissing. More of a whistle, but it does have a very slight hissing noise where it didn't before. Who knows, we both might have boost leaks, but I think it might be normal. Keep me updated so I know if I should check or not.

[OneBadAudi]

Yup Same thing with my car, it got a little bit louder and when i hit the gas around 3k and it spools you can hear it..I like sitn next to jersey walls and doin it..haha..Sounds cool

[HeymyAudi]

Get a Boost Gauge Son.... It lets you know the moment something aint right... It will be your friend....

[doublezero30]

i run a bailey motorsports DV too and i get a hiss too. had it on my old 2002 a4 and on my current 2004. im not too worried about it. sounds just like a rush of air right? that seems to get faster as you accelerate? deff not the turbo.

[A4 KiDD 810]

i run a bailey motorsports DV too and i get a hiss too. had it on my old 2002 a4 and on my current 2004. im not too worried about it. sounds just like a rush of air right? that seems to get faster as you accelerate? deff not the turbo.

Yup thats exactly it.

[jrau13]

Kidd-check this thread http://www.audizine.com/forum/showth...%27s+this+hose

I had a similar issue recently and it was this piece. It would only happen under boost but other than that the car drove fine. Do a boost leak test and you will hear air escaping from around this area if this is the problem. Its a tough one because it would only happen under boost so other than that the hoses and the actual pump looked perfectly fine. When boosting it would separate.

[A4natomical]

after i put my atp manifold on, i had a super loud hiss, almost screeching sound. but the mani to turbo bolts werent torqued enough. just trying to throw things out there.

[102487thedude]

Do a Boost leak check. Check around the derverter valve and all the boost piping connections. also check intercoolers make sure nothing craked one. Also check the oneway check valve on the top of the motor behind the intake manifold it is common for the valve to crack when running more boost. Also if you have changed injectors make sure you seated them good and did not pinch the o ring if so boosted air can escape creating the noise as well. Check this link out.

http://www.audizine.com/forum/showth...=Secondary+air

[jrau13]

Good info but that's the same link that I posted. Just sayin'

[102487thedude]

Good info but that's the same link that I posted. Just sayin'

Damit didnt see that. hahaha

[A4 KiDD 810]

BUMP ! Now I know 100% it's a boost leak. When I got home today I actually made sure that my APR 1+ was in chipped mode. Car just isnt pulling the same now. Gotta get this crap looked at soon. For some reason I just get this feeling its one of the hoses on the DV that came loose from so much boost or something. Whatever. The crap never ends.