its an oem part... does it matter?

its a pcv1264 pc287

The plastic ones from autozone frequently leak and fall apart. The one from the dealer is of much better quality and they usually don't leak though some people have had multiple 323 pcv's from the dealer that did leak so it's a toss up. PCV valves are a headache though, it's a real PITA finding one that doesn't leak. Ideally I would like to run no PCV at all.
Short story, the one you bought at advanced is a cheap plastic piece of junk, don't expect it to hold boost.

ok, i had no idea i should change it until i was reading up on some shizz and i saw that i should upgrade to the 323gtx.... what do you think about the FM upgraded one for turbo apps?

Pretty sure that is the same exact one you can get from Finishline Performance for less money. It is a dealer part, you can usually get it for $22 or less direct from your local dealer.

so i should go get my 4 bucks back? and go to a mazda dealership and get an 85-89 323gtx pcv? or should i get the one from fm?

Yes get an oem unit. The pcv valves from autozone etc will most likely leak boost into your valve cover.

aiight, thanx for the info guys

any advantage to running it on an NA set-up? i'm going turbo soon, so i should i just pick it up to have for later use? or can i install it now?

Won't hurt to install it now. The only benefit to this valve is it was designed to hold boost better than the stock miata valve. Even if it wasn't designed to hold boost better, it usually does.

Does the factory 1.8 PCV valve hold any boost at all? Anyone ever test this?

The OEM valves are pretty decent. The problem with them is by the time people turbo their nearly 20 year old car the valve has failed anyway so they wouldn't even hold you blowing through them. I'm currently running an advanced auto PCV that doesn't leak when i blow through it. That doesn't mean it doesn't leak at 10-15 psi.
I need to hurry up and VTA my VC to a catchcan.

I WAS using a metal aftermarket (supra) and in less than 2k miles it failed. Found an old valve from a B engine in the garage. Tested good to ~40psi. It's been said over and over, buy the OE Mazda pcv valve.

This is why my new car isn't going to have a pcv setup. For once I'm going to borrow advice from Honda tuners and simply run major ventilation to the crankcase.

My only concern is cutting down the frequency at which water vapor is removed from the engine. It'd be different on the track where the car is in boost most of the time, blowing out vapor. But on the street, vacuum plays a major part in removing the vapor. I think it's important to have both- surely can't hurt, and with the addition of for-boost modified vent system, it'll only extend the life of the pcv.

How do you know if your PCV spontaneously broke? What are the symptoms?

I bought a 323GTX PCV from my dealer for 23 bucks, I told him the part number and said the model + year of the car. I dont think it has a metal end though. I just explicitly said I need this part number exactly and not a "compatible" part.

my last engine has very very very sensitive rings. I couldn't even run a catch can because the pressure drop of the can itself was enough to remove any ventilation through it.

when my cheap $1 pvcs would fail i'd notice more oil smell in boost and fun trails out the exhaust :)

Depends on the engine- some symptoms include: oil leaks, around the filler neck, from the cam cover gasket, dip stick popping up. You can test it with an air compressor- just use the blower attachment with the regulator set to the desired psi and try to blow through it.

what exactly happens when a PCV goes?

READ THE THREAD.

I just asked.