Valve cover breathers, yes or no

[Mishakol129]

Got one of these puppies last week but people have been saying that they don't allow the PCV system to operate as the manufacturer designed it to and could cause premature wear in the engine.
Is this true, and should I leave the vacuum hose attached or not?

[EsperHamid]

do you mean you want to remove the PCV and attach it directly to the IM ?!

[toycar]

Pointless

[Raf99]

Pointless

Agreed. And the point is to exhaust any gases and "crud". I can't see it going too far with a filter on it.

[sonikaccord]

That's not what he's saying. He's talking about the other tube attached to the valve cover. I can't answer the question but I don't see how it could affect the PCV system.

Edit:
The vacuum from the intake pulls that crap out of the crankcase. If you use the filter instead, the crankcase pressure vents to the atmosphere with a fair amount of force. Take the tube off and put your over the opening and you can feel the air pulsing out.

[EsperHamid]

yeah that other tube attached to the valve cover ( not the PCV one) does it let fresh air into the crank case or does it take air out of the crank case ?,,,members are saying it is taking air out ,,but I believe it is sending air in ..because if it is taking air out then it will eventually return it to the IM via throttle plate or IACV or FITV similar to the way the PCV let air into the IM

[GhostAccord]

yeah that other tube attached to the valve cover ( not the PCV one) does it let fresh air into the crank case or does it take air out of the crank case ?,,,members are saying it is taking air out ,,but I believe it is sending air in ..because if it is taking air out then it will eventually return it to the IM via throttle plate or IACV or FITV similar to the way the PCV let air into the IM

The port on the left side of the valve cover is the fresh air inlet/feed. The PCV valve port uses manifold vacuum to pull the crankcase gases out and when those gases are pulled out via the PCV port, fresh air is sucked in from the fresh air port.

You can place a small filter on the valve cover fresh air inlet and it will not hurt anything. As long as you retain the vacuum from the intake manifold it should stay fairly clean and work as the PCV system should. If you remove the PCV hose (vacuum) from the valve cover you will have crankcase gases coming out of both ports, along with dirty old oil and the smell of dirty old oil coming in your vents.

Been there done that! If you want to remove vacuum from the crankcase and let it vent to atmosphere you could try using an old V8 style valve cover breather. This will at least keep the dirty old oil from leaking out. However, you will still smell when your oil needs to be changed.

[EsperHamid]

this confirms what I was saying, I am not the OP of the thread by the way, but thanks for confirming it.

I am not planning on removing the PCV at all, when my original PCV wasn't working I plugged the tube on the IM and removed the PCV with the hose, the smell was awful because of the toxic gases, it gave me a headache and a clearly bad mileage I can confirm that !! however CB7 idled perfectly

in anyway I think it is necessary to have filters on both the PCV hose and the Fresh air breather hose.

[jdm92_accorn]

the best thing i've found so far on mine is pick up something to filter out the oil like a cheap ebay catch can on the pcv valve side then use a standard valve cover filters. works like stock minus sucking so much oil into the pcv system.

[EsperHamid]

I agree, oil shouldn't be in the IM at all