[Raven18940]

So I took my dump valve off today to try and figure out if it's busted. It's been making that hooting noise, but not all the time so it's been bugging the hell out of me. I blew into both ends and it held the pressure just fine. So I'm wondering what's making this god awful when I'm at zero pressure. It's only when the turbo gauge is on the border of white and the yellow/green/I'm colorblind. If I boost or lift it goes away and it doesn't happen all the time. I've been looking at other people's aftermarket valves and they all have the vaccum line on the top, but the bosch unit seems like it's turned on its side. Is that normal, or did some one put my valve on the wrong way?

 

[saabnc]

I'd say you might as well replace it, you'll have to eventually. :roll:

 

[Raven18940]

I'm not replacing things that aren't broken........least not if they won't increase performance in some way. :cheesy:

I sprayed some WD-40 in there to see if that'll help.

 

[saabnc]

Well if it is "hooting" then there has to be a leak in it somewhere I would imagine.

 

[Chris 9-5]

I've been looking at other people's aftermarket valves and they all have the vaccum line on the top, but the bosch unit seems like it's turned on its side. Is that normal, or did some one put my valve on the wrong way?

The bosch valve should look the same way round as the aftermarket one

 

[Raven18940]

Hmmmmmmmmm, I've seen them both ways now. I'm confused.

 

[Chris 9-5]

This is how Saab intend it

 

[Chris 9-5]

Another pic!

 

[Raven18940]

Now that's a problem, cause I wasn't able to get that vacuum line off. It was on there pretty good and I didn't want to push my luck as it was plastic and all.

 

[Chris 9-5]

There should be enough excess length to lose a small bit by cutting the pipe, surely

 

[Raven18940]

Yeah, there is, but I hestitate every time I have to do something on this car. Even a little thing like cutting a vacuum hose, I really don't wanna screw it up.

 

[nphobb01]

I guess if you think about it, it doesn't matter which way the valve goes. The valve is opened by the vacuum line right? In that case, until that line tells it to open, air can't go either way through the valve. If that is the case, then it does not matter which was the valve is oriented, it is either "on" or "off" until activated by the vac line, and should block the air coming from the turbo equally well from either direction.

 

[Raven18940]

I guess if you think about it, it doesn't matter which way the valve goes.

You see, I would have realized that if I knew how BOV's worked. I thought it was spring loaded and when the boost was more than the spring could hold it opened. I always wondered what that silly vacuum hose was for.

 

[Kermit]

The Forge ones are spring loaded, thats why they are so reliable. The Bosch jobbies rely on a rubber diaphragm, that eventually splits and makes the owl/hooting sound that is a tell tale sign its broken.