Weird BOV sound after lifting off throttle

[Damian_H1]

after i get into boost and let off or switch gears there is a weird blow off valve noise, very loud, Any ideas been doing some research and the diverter valves could be the cause of issue

[vavJETTAw36]

Sounds like leaky diverter valves (bad diaphragm). What DV's are you running? They tend to make more noise if they are installed backwards as well.

[Damian_H1]

i have the forge 008, full stage 3. Build list if needed: https://www.dropbox.com/personal?pre...3+S4+Avant.pdf

[Damian_H1]

Sounds like leaky diverter valves (bad diaphragm). What DV's are you running? They tend to make more noise if they are installed backwards as well.

Any suggestions on getting good ones, if it is a leaky dv would you suggest not driving or just stay out of boost?

[vavJETTAw36]

Any suggestions on getting good ones, if it is a leaky dv would you suggest not driving or just stay out of boost?

Forges are Piston type DV's. They do not utilize a rubber diaphragm that can cause it to leak. Are these new to you? If so, it is probably a normal sound. I have turned my Forge 007's backwards to allow for a better fit with my WDR bi pipe. They are louder this way.

If you arent having trouble making boost and your AFR's are fine, boost on my friend.

[Damian_H1]

Ok thank you very much

[vavJETTAw36]

Ok thank you very much

no problem. If you're not sure the last time the DV's were lubed, you may want to open them up and regrease them. This should be done at least once a year.

[LJS]

You may want to rebuild your valves---The kit is only $17 from Forge.
https://www.forgemotorsport.com/Forg...duct--792.html
FWIW-I've been running Forge 007's since late '01 and changed the o-rings and pistons once in some 65,000 miles of use.
I've never heard that noise you mentioned then again I'm only a wee Stage-II and not running the boost levels you'll see.
As stated earlier a yearly re-ube is a real good idea.

[Damian_H1]

Ok thanks I'll look into that

[Damian_H1]

Here is a sound clip I took from early today hope it helps https://youtu.be/iZ87xf01i0s


Sent from my iPhone using Audizine

[Damian_H1]

https://youtu.be/pgF1EmmNrOY


Sent from my iPhone using Audizine

[Damian_H1]

I've never had frankenturbos on any of my b5s and I've never heard this sound with my k04s so I'm a little concerned

[cu52]

Sounds similar to when my DV's were leaking. They were the old 710A and could not hold a vac. Have a MityVac? if so connect it to the DV nipple and see if they hold vacuum, if not rebuild/grease them

[cjt671]

Sounds similar to when my DV's were leaking. They were the old 710A and could not hold a vac. Have a MityVac? if so connect it to the DV nipple and see if they hold vacuum, if not rebuild/grease them

To add you can also push the diaphragm gently and then cap the vac line port with your thumb as a quick check if the diaphragm stays put it's good


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[Damian_H1]

Ok thank you