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New PCV valve defective or not


adallak

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While I am waiting for an PCV elbow and grommet to replace the dried out ones, I have checked a new Puralator PCV valve I ordered some time ago.

When I blew on it, it flows freely one way like it should, but when I turn it around and blow the other way, it doesnt seal COMPLETELY... If I push the valve with a finger while still blowing to make it sit properly, it seals COMPLETELY. The problem is that there will be nobody in the engine to push the valve until it seals completely... The PCV valve is made in the USA, if that matters.

Should I get an OEM part, or it will do the same thing?

The saddest thing in life is wasted talent

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I remember it operating as you describe (complete restriction is never realized). Here is a portion of explanation:

At idle, the intake manifold vacuum is near maximum. It is at this time the least amount of blow by is actually occurring, so the PCV valve provides the largest amount of (but not complete) restriction. As engine load increases, vacuum on the valve decreases proportionally and blow by increases proportionally. With a lower level of vacuum, the spring returns the cone to the "open" position to allow more air flow. At full throttle, vacuum is much reduced, down to between 1.5 and 3" Hg. At this point the PCV valve is nearly useless, and most combustion gases escape via the "breather tube" where they are then drawn in to the engine's intake manifold anyway.

Chuck

'19 CT6, '04 Bravada........but still lusting for that '69 Z-28

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