vals1kid

i was having oil come out of the valve cover breather and into to the intake hat of my D1-sc so i changed it out and made a separate breather for it... at idle it is fine but when under boost oil sprays out of the breather and all over my engine bay. what can i do now since the original setup didn't work and now the breather doesn't work either??? thanks guys.

Bryan Wilkinson

iTrader: (1)

It is a known problem with the D-1SC, contact ATI, for a repair.

Bryan
lunapark@perigee.net

kp

iTrader: (34)

do you have a check valve on your PCV? If not the boost will blow right by the PCV.

If not thats your problem, that or you have a hole in the top of one of your pistons..

vals1kid

no i don't have a check vavle. i hope thats it.

Grasshopper

Do a compression check to make sure the engine isn't hurt. You could be getting too muuuch blow-by from a broken ring.

vals1kid

i bought a check vavle today. i have just a rubber hose running from the metal inlet on the valve cover to a breather... can i just put a check valve in between the breather and the valve cover or do i need to do soemthing else? can i out a cap on that metal piece? thanks guys.

QuickSilver2002

The check valve goes on the PCV inlet (not the fresh air source). Your PCV system has two sides (the inlet and the fresh air source). The inlet is where crankcase gases are sucked out of the valve covers and into the intake. The fresh air source is used to allow fresh air in and keep the air moving (without it the crankcase would end up at a vacuum similar to the intake and not that much air would move without blowby). In a stock configuration, the fresh air source is routed to the air filter box.

Look for the line coming out of your intake manifold (near the throttle body). You should see the PCV valve on it. The check valve goes after the PCV valve and prevents boost from pressurizing the crankcase via the PCV inlet. You want it setup to allow air to go into the intake manifold and not out. The arrow on the valve needs to point at the intake.

The breather you have hooked up to the line coming off the valve cover is your PCV fresh air source. Under boost, crankcase pressure created by blowby actually comes out this breather. Under vacuum conditions, fresh air comes in this breather.

Have you noticed a rough idle since you put the breather on? I would guess that you would have since it creates a pretty decent vacuum leak. Having it fight with the blower (or the air filter on a na car) keeps it choked pretty good. When you put a breather on it, air enters the crankcase at a pretty rapid rate. This air is not metered by the MAF and you end up with the car running a little rough under high vacuum conditions.

I still think you will have some issues after you put the check valve on. Blowby is pretty bad with the stock pistons and rings (even when they are in decent shape).

I have found there to be 2 decent solutions to the PCV mess.

1. Cap the intake manifold nipple and remove the PCV valve. Route all valve cover lines to a catch can. Run a line from the catch can to the blower inlet hat. I also suggest putting a small clear air compressor filter between the blower inlet and the catch can. This will allow you to see if any major oil is getting past the catch can and making its way into the intake.

2. Cap the intake manifold nipple and remove the PCV valve. Route all valve cover lines to a catch can. Allow the catch can to vent to atmosphere.

I like #2 because it completely eliminates the possibility of the oil getting into the intake. The downside is it is not very environmentally friendly and it makes the engine bay smell bad and get a slight oily film in it. If #1 works on your car, do it. It is the best solution if oil does not end up in the intake.