PCV Check Valve Options

[TwoSnelz]

I have an 034 Billet valve that is leaking a lot of pressure out of the ball and threads.. I just received a replacement I ordered and it leaks just as bad.

Testing off the car with just pressure from my Mityvac into the valve, it leaks about 2-4 psi a second. The new one is marginally better but still leaks around 2-3psi. The leak slows as both reach the 7psi mark. I am not applying any pressure or vacuum to the backside of the valve however.

Knowing this and assuming my test isnt flawed, I wont be using this thing and will be returning it.

But that leaves the question, what are my options at 21psi? Will a stock PCV hold pressure or should I be looking for a universal style in the size i need?

Thanks for your input as always

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[TwoSnelz]

I ended up ordering a high psi 1/2 inch one way valve off of ebay.. The plan is to run it inline with the 034 valve by just splicing it in between the 034 valve and the manifold.

Hope this works, will keep this thread updated.. I dont want to run a catch can if I can help it.

https://www.ebay.com/itm/30132939049...is&media=EMAIL


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[LJS]

FWIW-
I boost from 26psi tapering to 21 at 7200RPM and STILL have the original check valve in-place with no issues.....
I have a close friend with large turbos and boosting to 30psi with the same OLD valve in place and NO issues.
RE-
https://www.ecstuning.com/Audi-B5_S4...Emissions/PCV/
Save yourself some cash and use the OEM part--very cost effective and they work....
PS- you're not the first to experience a leaking billet valve from our friends at 034....

[TwoSnelz]

Thanks LJ, you are always helpful.

I am due to receive the valve today, going to install tonight and if it doesnt work out, Ill try the OEM valve.

Super pumped because i think this may be the boost leak i have been chasing for so long. Car is down but will come back up with this new pcv, a new check valve for the N249 which had a small leak, and a fresh fuel filter. Old one was pretty restricted.

Should be a good night lol

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[TwoSnelz]

This thing leaks worse than the 034 valve...

Stock it is.

Very frustrated.

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[wbrunner23]

I could bemistaken, but i don't believe the valve is intended to be a hard on/off, just restrict. Are you having an issue you are trying to resolved? Or are you just over thinking it?

[CELison]

The pancake valve isn't a check valve, I think they're talking about a separate one. I got rid of that so long ago I don't remember if it's a real check valve or a restrictor.

[RMode]

The pancake valve isn't a check valve, I think they're talking about a separate one. I got rid of that so long ago I don't remember if it's a real check valve or a restrictor.

it's an actual check valve if I remember correctly, like a traditional pcv. I got rid of mine too.

[Silverex]

Yea it’s a traditional PcV valve but all they usually hold is a couple PSI. So I don’t think the OP is experiencing anything out of ordinary.

[TwoSnelz]

You're telling me its normal for boost to pressurize the crank case through the valve?

The company who makes the one from ebay got back to me quickly and are sending a replacement free. It arrives friday alongside the oem one I ordered. They claim I received a defective valve.

I will test and see but I do not believe having boost pushing past the valve is correct, even if it is" just how it is."

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[CELison]

Nah if it’s from the IM it has to be a real check valve.

[B5carl]

You're telling me its normal for boost to pressurize the crank case through the valve?

The company who makes the one from ebay got back to me quickly and are sending a replacement free. It arrives friday alongside the oem one I ordered. They claim I received a defective valve.

I will test and see but I do not believe having boost pushing past the valve is correct, even if it is" just how it is."

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It's not normal for boost to slip by the valve and go into the crankcase. If it does you can blow through your front and rear main seals.

I also heard one of the versions of the 034 PCV had issues with the spring. The valve is supposed to fully shut at like 5psi+. If it's an old valve you might have grease and moisture preventing it from fully closing. You can try cleaning it out with brake cleaner. I would go ahead and put an OEM valve in a ditch the 034 since they had 2 versions that they updated for that reason and idk how you can tell which one you got

[harryn]

I'm glad I saw this thread. That 034 bleeder/check valve is trash and a rip off. I had one in my car as well, and was chasing a leak I could never find. It wasn't until I went back to the stock bleeder/check valve that my car was running properly again. Stay stock, stay happy (where applies).

I'm pretty shocked at 034 Motorsports. It's like they've turned into a Chinese Ebay/Amazon Quality brand now. I'm staying away. I don't know what's happened with them. Such a great history, but recently, I avoid the brand like the plague. Shame.

And yes, I've taken mine out, cleaned it, greased it, blah blah blah, no change. I'm sticking with stock.

[Silverex]

You're telling me its normal for boost to pressurize the crank case through the valve?

No and yes..lol.

I agree you shouldn’t push psi into crank case but every stock plastic PCV I’ve tested leaks if you put about 20psi to it. That’s new and old ones across multiple platforms, my assumption it’s not enough to matter. I tried the 034 billet piece on my Avant but it started sticking so went back to stock. While it was working I didn’t notice any difference.

[TwoSnelz]

I'm glad I saw this thread. That 034 bleeder/check valve is trash and a rip off. I had one in my car as well, and was chasing a leak I could never find. It wasn't until I went back to the stock bleeder/check valve that my car was running properly again. Stay stock, stay happy (where applies).

I'm pretty shocked at 034 Motorsports. It's like they've turned into a Chinese Ebay/Amazon Quality brand now. I'm staying away. I don't know what's happened with them. Such a great history, but recently, I avoid the brand like the plague. Shame.

And yes, I've taken mine out, cleaned it, greased it, blah blah blah, no change. I'm sticking with stock.

This is where I am with this car now. Ive learned a lot and fixed a bunch of tiny things from the inlet leaks to green check valves to verifying wastegates but have yet to locate my missing 3-4 psi. I started looking for internal leaks harder and here I am. The valve seems to work with lung pressure but i only discovered the leak after mityvac'ing it

I dont have much to say about 034. This is the first bad experience I have had.. I have a lot of their parts on my car, all of the silicone is 034 and fit great.

Valve comes tomorrow, hope the car rips this weekend.

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[replica_rs4]

I too have 034 spider hose and have been contaplating this set up.
Im gonna try capping off manifold port and that billet valve and just leave pancake valve port hooked up. My concern would be whether i should keep pancake valve or not .
At idle with pancake valve flow would be restricted from crank, without might have too much vacuum when ripping it.

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[CELison]

I only have the pancake valve with a THEtuner catch can. Which is a massive piece of shit btw. Don’t buy one.

[TwoSnelz]

Haha it is kind of funny I saw that thread's tone completely change right around the time I started really researching my issue hard.

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[TwoSnelz]

I now have a leaking OEM valve as well as a leaking upr aftermarket valve.

Something is off, is my test flawed? Or do I have really bad luck? My gut says its my test.

https://streamable.com/q65ufd

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[LJS]

FWIW--isn't it supposed to be pressure tight when pressure enters from the LARGE end---that's the end that runs to the distribution manifold on the spider hose which is connected directly to the base of the intake manifold....
PS- wish I could be more helpful...

[TwoSnelz]

There is a half inch connection that runs directly to the manifold. The one inch connection runs to the spiderhose. I am pressurizing the intake manifold facing side. The other side(fat side)can be blown through freely.

Honestly i think ive invested way too much time and brain power into this and am just going to end up blocking the port off and going down that path.

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[Silverex]

Honestly i think ive invested way too much time and brain power into this and am just going to end up blocking the port off and going down that path.

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Yea I gave up after testing a bunch testing also.

Why not just run a stock PCV/spider setup like tons of stg3+ guys run instead of blocking off?

[TwoSnelz]

I just put the car back together. I ended up just putting the oem pcv valve into the 034 spider hose and then I spliced in one of the upr valves I got running inline to the manifold.

The car idles a hell of a lot better and the honking on shifts, which started this whole debacle, is gone. However, I changed the fuel filter and the 4 way check valve as well since last starting it and Im still down on boost sadly.

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[CELison]

What turbo/wastegates setup? If it’s any of the China ones, weak gates is par for the course.

[TwoSnelz]

Cel, f21s and Ive looked hard at the gates. Ive pressure tested them both and they open same time/hold psi.

I just disconnected wastegate lines from n75 to be sure and it wants to overboost so im pretty sure they are sealing fine.

N75 ohms at 33 but maybe I should try another, it would be the third one ive tried but maybe 3rd one is the charm?

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[CELison]

I had the same problems with my f21s. Doesn’t matter how much you tighten the gates or what the cracking pressure is. The springs weaken and you can’t reach full boost. Not saying this is what you’re experiencing, but it’s very possible.

[CELison]

Whoops, read past the part where you said it will overboost if the wg lines are disconnected. It could be the gates getting weak at the n75 duty cycle it was tuned on.

[Silverex]

Next time you have the downpipes off take a good look at the flapper. There’s like a little washer that hold it in place and they open up over time creating play. My F21s had that issue which I initially remedied with an E clip which lasted over a year. Later I tack welded them so I would worry about the clip popping off anymore. Made a pretty big difference, better boost control and gained about 250-400rpms of spool.

[TwoSnelz]

The flex pipes are starting to look like crap on my downpipes so maybe I will pull them and visually inspect that flapper, thanks both of you.

I toyed with the idea of some helper springs but after doing the disconnect test I figured gates were fine.

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[vavJETTAw36]

In my experience, the 034 billet gets stuck open constantly with fod effectively creating an internal boost leak. I turned to an aftermarket check valve made by UPR. The valve alone was too large an orifice that it would draw too much vacuum on the crank case, so I ran both the 034 (since It was already installed) and the UPR valve... Eventually i got tired of removing the F hose to do some maintenance tasks so I ended up deleting it all together.

[TwoSnelz]

Vav that is exactly what I ended up doing but went with the OEM valve in place of the 034. I think it was you who posted the solution in whatever old thread I was reading before attempting so thanks for being the guinea pig haha

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[vavJETTAw36]

Vav that is exactly what I ended up doing but went with the OEM valve in place of the 034. I think it was you who posted the solution in whatever old thread I was reading before attempting so thanks for being the guinea pig haha

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I am glad that solution worked out for you. How's your car running lately?

[B5carl]

No and yes..lol.

I agree you shouldn’t push psi into crank case but every stock plastic PCV I’ve tested leaks if you put about 20psi to it. That’s new and old ones across multiple platforms, my assumption it’s not enough to matter. I tried the 034 billet piece on my Avant but it started sticking so went back to stock. While it was working I didn’t notice any difference.

The PCV isn't supposed to leak at all. The 034 billet valve was supposed to solve that issue against the OE plastic units out there. You tested some at 20+ psi but thats not 20+ psi thats inside the crankcase or you'd be in trouble. As for the idle 034 apparently didn't get it right the first or second time with their valve.

[vavJETTAw36]

The PCV isn't supposed to leak at all. The 034 billet valve was supposed to solve that issue against the OE plastic units out there. You tested some at 20+ psi but thats not 20+ psi thats inside the crankcase or you'd be in trouble. As for the idle 034 apparently didn't get it right the first or second time with their valve.

You wouldnt see much of any pressure on the crank side since thats the direction the valve opens at. The valve blocks pressure coming from the manifold, which could be 20+ psi.

No, I would never pressure test above 15psi.

[TwoSnelz]

Just had a thought, sitting in a chair on vacation.

With the way the spider hose is ran, any pressure getting past the check valve from the manifold runs immediately into the distributor piece where blow by from the crank case and valve covers are pooled before being sent to its final destination based on manifold pressure/vacc.

Correct me if I am wrong but by design, on manifold vacuum, blow by is sucked directly in through the pcv valve's open side. On boost it is directed through the pancake valve, because manifold pressure would be higher than crankcase pressure, forcing it to the pancake.

Wouldnt that mean any boost leaking through the one way check valve would not enter the crank case but actually leak to the pancake? Would it not follow the path of least resistance?

My logic is the crankcase is probabably operating at neutral or slightly positive pressures on boost where the intake tract after the pancake is in a neutral or slight vacuum state. The leak would meet less resistance at the pancake and tge air would flow towards it instead of the crank.

Has the sun cooked my brain?

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[Silverex]

That makes sense to me and explains why them leaking isn’t a big deal. Nice job!!!

[vavJETTAw36]

Just had a thought, sitting in a chair on vacation.

With the way the spider hose is ran, any pressure getting past the check valve from the manifold runs immediately into the distributor piece where blow by from the crank case and valve covers are pooled before being sent to its final destination based on manifold pressure/vacc.

Correct me if I am wrong but by design, on manifold vacuum, blow by is sucked directly in through the pcv valve's open side. On boost it is directed through the pancake valve, because manifold pressure would be higher than crankcase pressure, forcing it to the pancake.

Wouldnt that mean any boost leaking through the one way check valve would not enter the crank case but actually leak to the pancake? Would it not follow the path of least resistance?

My logic is the crankcase is probabably operating at neutral or slightly positive pressures on boost where the intake tract after the pancake is in a neutral or slight vacuum state. The leak would meet less resistance at the pancake and tge air would flow towards it instead of the crank.

Has the sun cooked my brain?

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I completely agree with that assessment.

I chose to simplify it and just remove it entirely. However, now theres not much to pull the crank case vapors out other than what little bit of negative pressure coming from the pancake. Though I am not sure there is any since its not a venturi design. Oh well, this is why I stick with 5k oil changes.