BOV Always leaks because it doesnt close

[DSM-Talon-John]

Ive had this problem for quite a while but never noticed it, my bov is always leaking out of the recirc area, even at idle. I cant even do a boost leak test because it all leaks out of the before any pressure can build, but the wierd thing is I can build as much boost as I want. It doesnt hold all that well at all but still boosts up to 15-16 psi. I have it tightened all the way down.

 

[1stGenRocks]

its normal for it to be open at idle. it opens whenever it see vacuum on the small line

 

[oldman]

Ive had this problem for quite a while but never noticed it, my bov is always leaking out of the recirc area, even at idle. I cant even do a boost leak test because it all leaks out of the before any pressure can build, but the wierd thing is I can build as much boost as I want. It doesnt hold all that well at all but still boosts up to 15-16 psi. I have it tightened all the way down.

How do you know this if it's recirculated? Where are you tapping for pressure source for your mbc?

its normal for it to be open at idle. it opens whenever it see vacuum on the small line

This only true when the spring pressure is less than vaccum so it depends greatly on which BOV and spring adjustment.

 

[DSM-Talon-John]

I took thr recirc tube off and you can here it leaking, and when i do boost leak tests i cant build pressure because it all comes out of it. IM using a greddy rs. Im wondering why i can build 15psi when my bov leaks like that, it doesnt move up or down either when adjusting and also when reving it.

 

[92awddsm]

Take the bov off and make sure the seat isn't cracked and no trash on the seat holding the valve open. Ive seen a type s do the same thing and come to find out, there was a small piece of a sticker on the seat and the valve wasnt sealing up when closed.

 

[oldman]

I took thr recirc tube off and you can here it leaking, and when i do boost leak tests i cant build pressure because it all comes out of it. IM using a greddy rs. Im wondering why i can build 15psi when my bov leaks like that, it doesnt move up or down either when adjusting and also when reving it.

You're able to maintain 15psi because your turbo is working overtime to make up for the leaks. How about that mbc info?

 

[DSM-Talon-John]

IM tapping the compressor housing and actuator

 

[DSM-Talon-John]

Well im heading home tomorrow where i have my allen wrench to open it up. You have no idea how hard it is to find one that fits.

 

[DSM-Talon-John]

OK one more question. Should my car feel faster after I fix it and right now is my turbo hurting itself by working so hard to get full boost.

 

[oldman]

OK one more question. Should my car feel faster after I fix it and right now is my turbo hurting itself by working so hard to get full boost.

Yes and yes. Not only you can be hurting the turbo, you can also be blowing hot air into your intake tract, degree depending on the size of the leaks. Before you go and take apart the BOV, which you might have to at the end as Keith suggested, try tightening the adjustment screw, the key is to make it tight enough to hold more boost while not enough to cause compressor surge.

 

[DSM-Talon-John]

Ya i know i have tightened it all the way, no luck there. Thank you for the quick info, i have a fake one left over for replacement parts if i need it.

 

[kmoore]

I hate to tell you this but I have had two Greddy type RS's and both of them leaked and both were defective. They did exactly what you are explaning: I couldn't pressurize the system during a boost leak test, I could not build boost very well, etc. When you take the blow off valve OFF (not apart) the car, can you see a little gap in between the diaphram and the bottom of the BOV? If this is the case, then your BOV is defective. Both of my Greddy type RS's were defective, like I said before, and I have now switched over to a HKS ssqv.

P.S.= Just out of curiousity, did your BOV "whistle" when driving really slow and lifting up on the gas?

 

[DSM-Talon-John]

Ya my bov does exactly what you said, funnny. Its defective, and the even funnier thing is my 19 dollar fake one worked like a champ. Goes to show you dont fix something thats not broke especially when it costs 200.