Hello, is there an easy way to test the PCV valve ? I have it hooked up to manifold vacuum, just want to make sure its' working (it is mounted in the stock oil galley cover under the intake manifold). thanks

also, is there a reason a valve cover breather is needed ? doesn't the PCV valve serve this purpose (reason i ask is because when i bought the car it has M/T valve covers with no breathers, just the one side has a oil fill plug).

1) Shake the PCV valve. If you hear a rattle, then it's good.

2) You missed my long thread about 2 weeks ago about crankcase blow-by on rebuilt engines. Fresh piston rings take a while to seat and the resulting blow-by creates a lot of pressure in the crankcase, especially at higher RPM's. You need to ventilate the crankcase with a PCV system and maybe either 1 or 2 valve cover breathers connected to the air cleaner. This lowers the pressure in new engines preventing you from forcing oil past your engine seals.

I found this out the hard way and that there is so much pressure in my nearly 500 hp 455 motor, that I need to hook up a 2nd breather and hose to the air cleaner. I was forcing oil past my real main seal.

Just my 2-cents on shaking a PCV valve to check if it's good. While I generally believe that works, I've found it is not foolproof. Recent experience with my Mopar smallblock, had a squeek comming from the engine compartment. I replaced the all the 10-year old belts, checked the water pump and alternator bearings but still had the squeek. Turned out to be coming from the PCV valve. Replaced the valve and the squeek was gone. You can replace the PCV for less than $3.00, if there is any doubt just replace it.