So, While engine is running, the PCV valve is making a very loud rattling sound. I'm guessing this is not normal.... replace it?
Also, I would be intrested in knowing what side effects a failed PCV valve might have. Thank you

 

Its my opinion the fact its rattling means its working. If it wasn't rattling a little bit might mean its clogged with carbon etc. My next question, is the one you have correct for your application?

If the pcv fails it could be stuck shut or stuck open, perhaps somewhere in between. Closed might mean excess blow by or smoke...from somewhere, Open might mean lower vacuum signal on a gauge and other issues.

 

It seems to rattle intermittently.
I've had this Car a long time, since 1991. Who knows how old that PCV valve is, and where I even bought it....
I have a 1977 olds 350 installed in a 1972 Oldsmobile Cutlass, If I am going to just replace it with a new one, should I purchase yhe part for the year of the car, or the year of the engine? Or, does it even matter?

 

Other issues could include unstable idle.

 

Are you sure the internal baffle in the valve cover hasn't become loose (un-tack welded) from the valve cover?
Yes PCV valves are specific for each application. A "will fit" PCV with the wrong spring in it will cause rough idle or excessive blow by.
Look into an adjustable PCV. Pricey but great part for super tuning and its made in the USA

http://mewagner.com/

 

Get the part for the year of the engine.

 

I checked vacuum, Im nearly at 18 at idle.... Its abnormally loud, if anything, and never was before. Ill post what happens after I install a new one

 

Ok, I installed a nice made in U.S.A. Delco PCV valve, noise gone!
I'm gonna throw it out there - rattling PCV is not normal.

 

Thanks for the follow-up. Glad it was simple. Where dd you find a USA made PCV?

 

My old timer neighbor came up to me with one in his pocket!
Guess he's had it for ever .....