So I bought my 99 in March of last year, and it was bone stock. I noticed that it would take like 1/2 -1 quarts oil oil between oil changes, but it would never smoke. Ever since I turbo'd my car, it seems like it's taking more and more oil between every oil change. This past week I noticed that it smokes sometimes between shifts. So this morning I yanked my PCV valve...it was oily on both sides. If I wiggle it back and forth in my hand, that valve moves freely as if the spring is missing or worn out. SO, this is most likely the, or the start of my problem. What PCV should I buy? Just a stock one? Or is there some drop in replacement that'll be better for my turbo application?

 

Buy a OEM Mazda 323 turbo PCV, not NAPA or Advance or whatever your local shop is, Mazda original 323 turbo PCV or nothing at all.

 

I think the Mazda 323GTX does not fit the NB valve cover. Cjernigan told me this I believe.

Thirdgen, just ditch the PCV all together and throw a filter on it.

 

https://www.miataturbo.net/forum/showthread.php?t=21599

 

Get a good PCV valve, you've been pressurizing your crankcase which keeps yours rings from sealing and pretty much screws everything up. Before you install the new one, pressure test it or atleast blow through it to make sure it doesn't leak. Most the ones from advanced and other parts stores leak.

You should look into a catch can and a normal check valve. There is a thread on this right now, m2cupcar started it. That would eliminate the PCV valve and the possibility of pressurizing the crankcase.

The 323 valve fits the NB, the hose just has to be bent a little different then normal.

 

What about this simple idea...My breather from the valve cover on the drivers side is connected to the vacuum side of the turbo. In stock form that breather was connected to the air tube from the filter box, to the throttle body. Thus being, vacuum all the time to the drivers side breather.
My PCV valve is on the passengers side of the valve cover, connected with a vacuum line to the intake manifold. How about I remove the vacuum line, plug the port on the intake, run a new line from the PCV valve, and T into the vacuum line that the breather uses. Therefore, there is never a chance that I can boost my PCV valve, or crankcase, and the gases will always be scavenged.

 

that thread linked by gwilo pretty much covers that and more