Really, you should test your vacuum at the actual BOV hose, with the car on, pull the hose off that goes to the BOV. The car might sputter or even die, but that would even be a good indicator. With a pull-type valve, vacuum on one end and boost on another should cause it to open. Are you getting NO noise whatsoever when coming out of boost? If the BOV isn't opening, then the pressure should find its way back to the compressor and make the real cool "ch ch ch ch ch" noise ricers like. I wouldn't go for a motor issue because as long as you're pulling good vacuum and boosting well, the BOV should work.

So, explore the actual hose that goes from the intake manifold to the BOV and the port the hose plugs into on the intake manifold, could be as simple as something being clogged or having a crack in the line or something along that idea.

1500+ posts and asking this?

Yeah, I can't figure it out. Believe me I been told wrong by others with more post count then me. Post counts are irrelevant.
Right now the 1 gen is on the car. When I take off the hose(from manifold to bov) it does kinda choke, hesitate at idle.
Im picturing this; so when car is in load, you let of gas, bov goes psh. So possibly it's loosing pressure somewhere between turbo > throttle body??? I water/soap spray the throttle body seals and surrounding sensors, no leaks. Confused!

my dreamt dsm said:

Yeah, I can't figure it out. Believe me I been told wrong by others with more post count then me. Post counts are irrelevant.
Right now the 1 gen is on the car. When I take off the hose(from manifold to bov) it does kinda choke, hesitate at idle.
Im picturing this; so when car is in load, you let of gas, bov goes psh. So possibly it's loosing pressure somewhere between turbo > throttle body??? I water/soap spray the throttle body seals and surrounding sensors, no leaks. Confused!

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I know this might be a stupid question, but do you have a boost gauge so you can see if there's any issues with the vacuum under a load? If it stutters when you remove the vacuum line at idle but isn't actually opening up the BOV it could be a leak that may not be apparent at idle.

Yeah but regardless of bov it still doesn't psh. I tried the greddy types, knock off type s, hks, and now I'm back on the 1gen. So I know bovs aren't the problem.

How much boost are you running? Did you answer whether or not you have a boost gauge? What does it read at idle?

wmrcs said:

How much boost are you running?

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This.

If you're running near-stock boost levels you aren't going to hear shit. The biggest part of the sound is diffused by the MAS if you're recirculating.

Yes I do have a boost gauge. That's why I know vacuum is holding 17-19 hg.
I'm running a hacked maf with the side comb removed. Stock OR removed NO difference in noise. I ran an fp17psi actuator on my t25 then, I was running 16psi on my evo16g, and now I turned it down to 10. Regardless of psi. No noise.
Could a bent intake valve cause this?

Also I can't find if you stated this earlier, but are you hearing turbo flutter from the pressure not having anywhere to go when you let off?

Unhook your recirculating pipe, use your hand to open up the throttle body and let it go. See if the valve is opening. On stock boost and rubber hoses, I couldn't hear my BOV at all. It wasnt until I got hard intake and intercooler piping when it got significantly louder.

Bov doesnt flutter. When i take off recirc hose it bearly psh. also. I talked to my cousin whos a mech. He said it could be a bent intake valve so air is getting into the chamber. Anyone elaborate his claims?

Letting air into what chamber? The combustion chamber? That's obviously not the case since you have good vacuum.

The BOV works off pressure difference. Boost in the pipes and vacuum in the manifold pulls/pushes the valve open. So if you have boost in the pipes, and vacuum in the manifold when you let off, the valve should open. Assuming it's not malfunctioning of course.

If the valve wasn't functioning at all, the compressor would be surging when you let off. The small amount of noise from the valve, and no noise from the compressor, is proof that the valve is functioning. Why it's quieter, who knows.

Is the boost controller hooked up correctly? Is it T'd in to the IC piping for a vacuum source and straight to the wastegate? Or is it T'd off another vacuum source?

mrslow said:

Is the boost controller hooked up correctly? Is it T'd in to the IC piping for a vacuum source and straight to the wastegate? Or is it T'd off another vacuum source?

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Boost controller is not t'ed. I comes from the inter cooler pipe and turbo housing.
Car is also running like shit though. Maybe that's the cause.

my dreamt dsm said:

Boost controller is not t'ed. I comes from the inter cooler pipe and turbo housing.
Car is also running like shit though. Maybe that's the cause.

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Could you clarify running like shit? That could help pin it down a bit better, possibly.

You need to do a formal boost leak test. Spraying soapy water and watching for bubbles at idle wont do you much good. The car will MAYBE push 2psi free revving. Buy or build a simple boost leak tester and set it to 18-20psi ( since your max was 16psi so far) and then spray soapy water and watch for leaks. Any of your intercooler pipes, intercooler itself, throttle body, or intake manifold gasket could be leaking. A big boost leak could easier be your reason for poor performance and your BOV issue. The BOV isn't going to make much noise if there isn't any air to be released.

mrslow said:

Could you clarify running like shit? That could help pin it down a bit better, possibly.

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My bad! Car feels heavy, like a 600 lbs man is sitting in the car.

ebailey95 said:

You need to do a formal boost leak test. Spraying soapy water and watching for bubbles at idle wont do you much good. The car will MAYBE push 2psi free revving. Buy or build a simple boost leak tester and set it to 18-20psi ( since your max was 16psi so far) and then spray soapy water and watch for leaks. Any of your intercooler pipes, intercooler itself, throttle body, or intake manifold gasket could be leaking. A big boost leak could easier be your reason for poor performance and your BOV issue. The BOV isn't going to make much noise if there isn't any air to be released.

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I conduct another boost leak test when I have time.

You've been here since 07 and have 1500 posts. Generally speaking someone who invests that much time in this forum should be able to diagnose something as simple as a bov. Forget the boost controller, forget boost leaks, forget compression. Run a decent sized vac line directly from the intake manifold to the bov. 100% straight there, no tees no anything. Ensure the line is getting vacuum. Now take the recirc tube off and hand rev the motor. If the valve opens your not running enough boost, if it doesn't open its your bov. Simple as that.

First determine if the valve is opening or not.

jakelandry said:

You've been here since 07 and have 1500 posts. Generally speaking someone who invests that much time in this forum should be able to diagnose something as simple as a bov. Forget the boost controller, forget boost leaks, forget compression. Run a decent sized vac line directly from the intake manifold to the bov. 100% straight there, no tees no anything. Ensure the line is getting vacuum. Now take the recirc tube off and hand rev the motor. If the valve opens your not running enough boost, if it doesn't open its your bov. Simple as that.

First determine if the valve is opening or not.

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Yes, it is getting vacuum from the manifold, I test that countless times. It can't be the bov. After 4 different bovs, 2 new ones. I ruled out the bov as the culprit. It has to be something deeper then bovs here.
I'm assuming that the 600 lbs man has something to do with why car is running heavy causing bovs not to blow off loud. I check many youtube vids of inside car drive with recirculated bov. I can't hear anything from mine.

my dreamt dsm said:

Yes, it is getting vacuum from the manifold, I test that countless times. It can't be the bov. After 4 different bovs, 2 new ones. I ruled out the bov as the culprit. It has to be something deeper then bovs here.
I'm assuming that the 600 lbs man has something to do with why car is running heavy causing bovs not to blow off loud. I check many youtube vids of inside car drive with recirculated bov. I can't hear anything from mine.

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Ok you've confirmed it has vac. Now physically put your eyes on the valve. Does it move when you free rev? Youll have to free rev somewhat hard to get a decent vacuum change.

BUMP, what was the problem?
I'm having a similar problem, YES I Know how a turbo system works including the BOV, swapped a few noisy ones (SSQV, Type S, RFL) even with all the vaccuum line and ran a new line, vented to atmosphere, and still no Pssh, mechanical boost gauge, @17-19hg vacuum, builds boost, checked for boost leaks, new oem gaskets, good compression, also did a Leak down test as a desperate move, its sealed and no hissing other than the usual ring leaks, and for sure I can hear the compressor surge noise.

It doesn't make sense to me, throttle body going bad? I tested the mechanism and it shuts off the plate pretty quickly