BOV??? WTF

[7m2ner]

:1zhelp: ok so i thought that i had a bad stock BOV, because when i would drive, and when i would let off the accelerator i hear a loud fluttering, becuase i am short of money i bought a used stock bov and i put it in and i hear the exact same thing, so i am thinking that i got fucked over, but is there a way that i can test the bov so see if it works, or might i have a diffrent problem? need help soon thanks

 

[supra90turbo]

You can test it, I believe the TSRM outlines that procedure.
Are you sure you don't have a vacuum leak somewhere? Listen for a hissing noise. I know when I put my engine in and got it running, my Blitz DD would flutter no matter what I did. Turns out I had lost a vacuum cap under the intake plenum.

Search around, spray brake cleaner around the area that you hear a hissing. When the engine idles up, you've found your leak, or the general area anyhow.

 

[MDCmotorsports]

To test a bov, simply try and blow threw it. If you can, its junk. If it pressurises (sp? Its late) but leaks slowly, its on its way out.

 

[flubyux2]

the diaphragm on the bov's could be torn or cracked and leads to an inactive bov. so its possible that its just hanging up and not releasing... which would explain your compressor surge, "Flutter". but ive also seen stock bov's that seized up and hung open, creating massive boost leaks.

 

[theDon]

very possible you got another bad stock BOV IMHO. Get yourself the $25 Bosch BOV, don't waste time with another old stock bov.

 

[7m2ner]

ok so i took the bov out, and i tried blowing threw it to see if it was bad, and i cant blow threw it, so would that mean that it is good?, if that does mean it is good, why am i getting compressor surge?

 

[suprabee]

ok so i took the bov out, and i tried blowing threw it to see if it was bad, and i cant blow threw it, so would that mean that it is good?, if that does mean it is good, why am i getting compressor surge?

YOu probably should just get the Bosh one, they are much better than stock BOV's. Do a search on here as it has been talked about alot... However,.....if you can't blow through the large opening, this is good and this is what the valve should do in a "closed" position. Then you should place a vaccum on the small tube and this should "open" the valve and then you should be able to blow through. It doesn't take much to open the valve. Of course, this method doesn't check at WHAT vaccum pressure the valve opens which is really more important for normal BOV operation and it could be your valve won't open at the correct vaccum pressure. I don't know the spec. Someone here might. This will tell you fundamentally if the valve "opens" and "closes"

Rick

 

[mkiiSupraMan18]

Is the vac hose AFTER the throttle body? I drove mine fluttering for a week or two before MDC told me that it had to be after, not on, the throttle body :icon_bigg

 

[boost fiend]

how much boost do you have built up when this happens?

 

[7m2ner]

how much boost do you have built up when this happens?

well i have tried not getting on it ever since it started because i knew that it was bad, but not not it happens even at vaccum, i dont even have to boost, because the car will do it if i give it gas when it is in nuetral.:1zhelp:

 

[flubyux2]

well, it could also be that the diaprhagm in the top of the bov is torn and leaknig. if this is the case, the bov wont OPEN when it should, causing the surge. put a hose on the nipple and suck/blow on it. if it leaks out relatively fast (draw a mouthful of air, cover hose w/ tongue, tongue doesnt stick) then there is a bad leak and its not opening.