Oxygen454

I heard what sounded like a bearing noise under the hood from inside my car. I opened the hood to find out that it was the PCV valve. The friggin thing was rattling like crazy!! I'm guessing its crapped out? Might be part of the reason my car idles rough. Its very loud like a bearing noise. Obviously the bearing is moving around inside there too much? This is really weird!

Oxygen454

I think I just answered my own question... for the rest that run into this problem, here is the answer... (replace is the main answer)

The PCV valve (positive crankcase ventilation) is designed to remove the harmful blow-by gases in the crankcase. The PCV valve is designed to have "variable flow" which uses manifold vacuum to draw crankcase vapors into the intake manifold. During idle, manifold vacuum is very high and blow-by pressure is very low - the pintle inside the valve will retract against a spring and only allow a small amount of blow-by to enter the manifold. If the spring pressure is nearly equal to the force on the valve from the vacuum the pintle will bounce and make a rattling sound. This can happen if there is low manifold vacuum at idle due to a long duration camshaft or late ignition timing - or the spring in the valve wore out.

Oxy