Tim Benton

iTrader: (1)

not to mention, I've seen a few engines that I "think" the PCV fucked up, allowing boosted air into the oil pan and front cover, blowing out the gasket on the front cover. Leading to an expensive repair bill to get to the front cover gasket. There's really no reason for the front cover to ever leak unless it was being pushed on. Leak meaning blown out gasket material in the 2, 5, 7 and 11 oclock areas.

Tim

soru81

Tim: But how do you explain that mazda eliminated it in 95? I eliminated it for the sake of cleaner engine bay... every hose counts.

badddrx7

iTrader: (7)

You can eliminate it. The crankcase is "vented" by the oil filler neck which has 2 nipples on it:

1) PCV valve
2) Line going to the inlet of the primary turbo

If you cap off the PCV, you aren't sealing anything. There is still the line going to the compressor housing. I eliminated mine because it was leaking and I didn't want to pay the Mazda price for a new one. As stated above, it was eliminated (along with the EGR) on the '95 car.

Sonny



This gentleman is correct. I did the exact thing on mine 3 years ago - NO issues. This was discussed long ago and deemed an ok mod.

Tom

DamonB

No. No. No. No.

You don't develop positive pressure until after the turbos. As long as the line goes to the actual intake in front of the turbos that line will see vacuum 100% of the time. That's why in stock form one is connected there from the oil fill tube. The other line from the oil fill tube connects to the inlet manifold which does see boost on occasion so the PCV also acts as a one way valve so boost can't make its way into the crankcase and pressurize it.

The car was designed with 2 lines because when under boost with only a pcv the crankcase would not be vented. A second line therefore runs to the intake side and that line is always "open". I believe it was changing emissions laws that allowed Mazda to delete the pcv even though functionally the system still performs the same purpose.

DamonB

The line goes BEFORE the compressor housing. This is where vacuum is always present as the turbo(s) constantly pulls air through the intake. If you plumb TO the compressor housing you now have pressurized air and that is NOT what you want.

DamonB

No. The line for crankcase ventilation must be run to a location in front of the compressor housing; that's why the stock twins have the nipples on the plastic elbow of the ptimary turbo. The wastegate and precontrol actuators OTOH need a boost source so they are plumbed from the compressor housing.

JayShadow

That Doesnt sound good, I just bought a replacement from fritz this morning. hopefully this will resolve my boost issues.

xb2002

I didnt meen intake as being fresh air intake... I ment intake as the "intake manifold/uim/lim, which is under pressure while boosting. I think that the glass man has his catch can vacum routed to the uim/lim and this is a no no.

mad_7tist

the purge controll solenoid/valve is for the fuel evap system.the pcv is different

DamonB

Sorry. I agree with you in that case then.

the_glass_man

iTrader: (2)

I have it located on my intake before the turbo.
Now I am confused. lol

mad_7tist

that will do

Tim Benton

iTrader: (1)

Just to clarify my statement, if the PCV valve messes up for whatever reason, it could let pressurized air into the oil pan and front cover gasket areas. There's no other reason for a front cover gasket to ever leak with the car running normally.

When you get the pcv from Fritz, just check it to see if you can blow through it like it says in the shop manual. Helps if you have a pump to pressurize the side that goes to the UIM to make sure it doesn't let air through at higher psi than you can think about trying to blow through there yourself.

Tim

JayShadow

update: i recieved the pcv valve from fritz. i blewn throw both sides and no arir came though either side. Thanks fritz