PCV Valve with boost.
 

I have heard different opinions on the stock pcv valve with boost. Will it hold up? Also, is it an emissions thing? I have no emissions testing and if it is something i can just plug up then its not going to be a problem. Thanks!

mine held up for about a month then failed. I now have a factory GTX PVC valve, works great.

Another option is a catch can, just do a search.

I went into advanced today to check out PCV valves to replace the plastic one i have that doesn't leak. Every single one including the all metal ones they have leaked. The point of the PCV is to remove vapor and pressure from the crankcase. You don't want your PCV leaking boost into the crankcase though.

My factory PCV valve crumbled when I tried removing it. After scavenging the pieces out of the valve cover baffle, I just left the hole open. I need to throw a filter on there or get GTX one.


I agree with Cjernigan, don't get one from the autoparts store. This would be a dealer item.

323GTX from the dealer.

Agreed. Dont skimp. Heres the part numbers " E301-13-890A ".

No need to "don't skimp"... the part is about $10... so cheap it's not even worth discussing when the alternative is having the stock one fail and eject the metal plunger into the rotating valve assembly.

Ask me how I know this.
https://www.miataturbo.net/forum/showthread.php?t=9920

does this apply to the NBs aswell??/ im kinda scared now

but if i just remove it and put a filter on it, its okay?

i've seen some video of ppl w/ just have filters on them and i think i see smoke or oil coming out of them under boost (dyno pull) so i guess it should be fine haha

Cjernigan has an NB and the stock PCV and he is fine.

Emmi, check the valve you have now. Take it out and blow in each side. If it can leak boost into the valve cover then replace it with a dealer part.

Got a related question... Why not just hook up the PCV valve upstream of the compressor, downstream of the filter? There should still be some vacuum (not sure if it is enough) and no potential of boost leaks.

i got my PCV from NAPA, looks real good and i dont see how the pieces from inside could come out or apart...has anyone tried the one from NAPA or is it the same as the ones from advance or autozone or wahtever....what should i do, get a dealer one or do we have good results with NAPA one...
help me out without scaring the crap out of me
thanks
Dan

I think the blow-by-mouth test is only good for a couple of psi- I mean how many psi can you generate with your mouth? My guess is a lot of these will leak at higher psi, where you need them to work most, and still pass the blow-by-mouth test. I've got a supra turbo third party valve and I suspect it's leaking at higher boost but there's no way I could make it leak by blowing into it. My test will be putting the compressor on it at the desired pressure level.

i think the most one can blow by mouth is about 2-3 psi, i tried this on a boost gauge, lol

but i think hooking it up to a compressor is the best way to test one...i may try that with the NAPA GSX PCV

I've done the mouth test on a digital tire pressure gauge. 3 psi at most and I have strong lungs. :)

Hook it up to a compressor to see.

:rofl:Ok girls, lets not see who can blow the best.

I'd be worried if it was a sucking contest

10 dollar part, known to fail if its a bootleg, and you want to experiment?

Oil saturated gasses will go into the turbo and coat your IC pipes.

Yes, I would LOVE to save $8 dollars and put my valvetrain and motor at serious risk.

Sam, i already have that PCV and figured someone had already used it and knows if it is a POS or not...i never said, lets try it now...re-read my post and yo will see what i meant, except take your time reading it this time, lol :magna:

i popped it out a week before the turbo install.. i'll check again tonight. kinda freaked out now. good thing i work weekends at an autoparts store XD

i just went to advance and got a gtx pcv. i still had the stock one in with just a breather filter on the VC. i noticed i had a tad of oil on the hood where the filter is. the advance sub $3 pcv sealed on the "blow trough test"

We already do that with the breather on the driver side of the valve cover.

The difference between the one you got at advanced and the one you get at the dealer is one is metal and one is plastic. The dealer part doesn't fall apart and shouldn't leak( they have been known to). The problem with the plastic ones is that they usually do leak, you can't produce 10 psi with your mouth to test how well it seals. The plastic one can get you by but it's sub ideal.
*I have a plastic one* :hustler:

Why mess around when there's a proven fix with a factory quality part for $10?

C

i changed out mine to an 'general' GTX pcv because it was right there and it was free... i tried comparing them side by side and it looks like the insides are different but the shell is similar

I was just going to order one from my dealer and they quoted me 21 bucks. Is that gonna be the standard mazda dealer price or do different dealers offer different prices?

Try Rosenthal or Trussville.

Rosenthal sells it for $12. I love driving past them on the way to work and picking up all my factory parts :)

12 + 5 for shipping = 17. I save a whole four dollars.

Any reason why theres is so cheap?

edit: just called a second place, 23.10 and id have to cross a toll bridge for 8 bucks to get it.

cause tommy orders and stocks his own factory parts. if you order from rosenthal, order from tommy or through finishlineperformance.com

Hmm, I guess ill have to see how much it will cost from them.

For fun I just called a place in the city and they quoted me get this.....26.25+tax.

Lol. I should call Mazda directly and ask how much for a lot of 50 and start selling them.

edit: finishline doesnt have the valve on their site.

i just bought one from the dealer yesterday,
it was 24.99
looked very close in size and shape, but insides were different
the car seems to hold boost better in second gear,
i think my old one was leaking due to excessive oil on breather
install took a grueling 25 seconds

I call mazda HQ this afternoon, wanted to find out about buying a lot of 50 units. They told me to go to the dealer and arrange a purchase of that kind of quantity and it was the dealers prerogative to offer me a bulk discount.

I dont get it, where does the dealer get its parts?

prolly at at the same place autoparts stores get them... they just charge differently

Anybody else put compressed air on their valve to test? I'm using a supra turbo after market valve and as suspected it's leaking. I put 20psi on it and it leaked all the way down to 5psi. It's about 2 years old, but only has 2k miles on it. Metal construction too.

I have a question. How are you testing it, meaning how are you regulating how much pressure you place on it?

My brothernlaw has a portercable compressed air tank and I wouldnt mind testing my new pcv before installing it.

depends on the compressor: If it has a regulator (most bigger units do) then set it to whatever the max boost is you're going to run. Put a hose on the manifold end of the valve, and the air blower attachment on the compressor. Then stick the blower in the end of the hose and squeeze the trigger. The valve shouldn't let any air pass. A really cheap compressor might not have a regulator, so you just turn it on until the air in the tank reaches your max boost level, then shut it off and proceed with the blow test.

Just tested a "spare" OE valve I found in the garage from a B engine and it had no leak at ~40psi.