Problem ..or not.Constant PCV valve rattle.

[MustangLX-5.0]

A few months back I replaced the PCV valve and grommet on my 96.The old one seemed good but it had never been replaced.Now,as of lately,while the engine idles,I can hear the PCV valve rattling constantly.

I pull the top pcv hose off the air duct before the throttle body,plug the end with my finger and it starts holding a good deal of vaccum.Enough to start making the pcv valve squeal.There is no oil blowby in the intake.And no oil coming out the exhaust.

Any ideas here?

 

[MustangLX-5.0]

Never mind.I fixed it.I took the pcv out of an abandoned stang here at work and now no more rattle.

 

[Skymarshal]

The PCV valve should rattle. Checking it involves taking it off and shaking it to make sure the little shuttle inside isn't stuck. If the other one rattles when you shake it but is quieter, both are probably still good.

PCV valves usually only fail when the inner shuttle gets stuck or gummed up and no longer moves back and forth.