legacycentral bbs

so i was once again messing with things under the hood trying to figure out how everything works, i was looking for the iac and was planning on cleaning the hoses out. at the same time i was trying to reset the cpu.

anyways i pulled a few hoses off and cleaned them out a bit and now when i let off the pedal after being in boost i here a whoosh sound, almost like our bov when the hose is disconnected but not as loud(i tried it real quick to hear it, ran horrible) i pulled it all apart to look for leaks but could not find anything, the car feels like it still has good power... i especially notice the sound going up hills in boost. maybe i've never noticed this before but i doubt it, although i have been driving around without tunes cause my caliper is sticking a bit...

any ideas

k&n, desnork, coffee cup are the intake mods

Well a desnork, coffee cup mod and a high flowing K&N will DEFINITELY give you a loud 'whoosh' sound once you get off of boost (i.e. taking foot off of the gas pedal).

I'm pretty sure you're hearing your BPV. An easy way to test would be to build boost and let off of the gas and listen for the noise. Then do it without building boost and let off the gas. If you don't hear the 'whoosh' when you let off the gas (and no boost pressure) then all you were hearing was your BPV.

The ability to hear your intake is the major results of the coffe mug. The whoosh you are describing sounds most certainly like the recirculating valve "doin' it's thang"

I don't know about why things changed before/after for you but if you have that silencer portion deleted you should definately expect these noises. My intake allows me to hear the air being sucked in at idle even. For sure mine is loudest when I pull off while boosting up a hill.

You say you cleaned out some hoses. How much would you say they were clogged up? More flowage equals more audible I should think.

i wouldn't be surprised if all i've said is not news to you. I am sure someone else will have a more insightful take

THANKS, i was thinking that it was my bpv, i guess cleaning out some of the carbon allowed for some more flow, i couldnt think of what else it could be. it only has just over 100,000 k on it. i was thinking maybe i cracked a pipe on it but it idles fine

If you did not replace the intake resonator with a c-mug when this began to happen I'd check that all connectors are on tight.

If there is a leak in the system the turbo will over-rev to reach the target manifold pressure & everything (turbo spooling/BPV) will sound loud.

i'm thinking i should replace all my vacuum hoses but it is hard to find the right sizes up here, i can get close but cant find in mm

I had a similar issue with a “whoosh” noise. Turns out I had blown a hose off my Y-pipe under my IC. The pipe was held in position up against the hose with enough force so that it only pushed off and leaked at high boost and when the throttle plate slammed shut, it was working like a “pop off” BOV. The car ran normal from idle up to a few pounds of boost, the boost was weird and random above that. I’m sure it was leaking boost, but with all the other noise going on at high throttle I didn’t really hear it, but the Whooooosh when the TB slammed shut was very noticeable.

Gary

i think that i fixed the problem, i finally got around to pulling my turbo inlet and outlet 90's off and check things out,
what i noticed that on the lip of the turbo air inlet there is a slot cut out of the rubber 90, and i could see a little oil running down the outside of the turbo, i checked the clamp and noticed it was loose as well. So thats where the system was leaking and the turbo was spooling harder to keep up right???

so i got in the car after cleaning that area and replacing the clamp and the blow off noise is defintely not has loud. i also replaced and clamped a few of the other hoses as well which could have helped but i think the main souce was the turbo inlet,


thanks for the help, i definetly appreciate it.

Yup the turbo was trying to maintain boost levels while having boost leak so it was working harder, but the fix was easy just find the leak & clamp it up...

i just installed an intercooler and an mbc, and of course removed the baffle under the hood scoop would all this combined cause the woosh to be louder than before? because it is noticeable louder than last night and all that has been changed since then is what i stated above.
should i start looking for a leak?
-Alex

The fact that you increased the boost pressure and you now have an IC sitting against the fire wall in front of you, will definitely make your turbo spool and blow off much much more noticeable. You will hear a hissing whine as you build pressure and some sort of whoosh once the TB closes as you release the gas pedal.