chattering pcv valve and egr question

I was doing some upkeep on my truck today, cleaning IAC, oil change, and grease job etc. I started the truck up and let it idle to reset the computer and noticed a strange noise that was the PCV valve. It was clean but chattering like you would not believe. Took it out and checked it out and then I put it back and it has not done it again so far this evening, but, I noticed that the small round valve was not always totally covering the opening, looked like it was out of round. I am going to replace it, as it has 20K miles on it and do a tune up as well. But I have never heard a pcv valve do this before. Any thoughts? 93S-10, 98K miles, 4.3 "w" engine.

A rattling PCV valve is not a bad thing.

But best to change it.

A quiet PCV would worry me more seeing it is probably stuck open or closed.

The darn thing sounded like an air compressor! Really strange. I forgot to ask the second half of my question and can put it in a different post if needed, but, I have had some minor stalling issues recently, usually when stopping or slow speed say, parking, and turning in a tight area. Truck runs OK at all other speeds and I keep it tuned up, but I have never looked at the EGR valve. I see posts where it needs cleaned every so often since it can clog open or closed. Would it cause a weak idle? The IAC seems OK, but I am watching it too. The idle seems to be right speed (around 800) as it always has been, just an occasional stall. I plan to clean the EGR this weekend to rule it out, but was wondering if this was possible. Seems most posts refer to poor running, non starts etc.

The darn thing sounded like an air compressor! Really strange. I forgot to ask the second half of my question and can put it in a different post if needed, but, I have had some minor stalling issues recently, usually when stopping or slow speed say, parking, and turning in a tight area. Truck runs OK at all other speeds and I keep it tuned up, but I have never looked at the EGR valve. I see posts where it needs cleaned every so often since it can clog open or closed. Would it cause a weak idle? The IAC seems OK, but I am watching it too. The idle seems to be right speed (around 800) as it always has been, just an occasional stall. I plan to clean the EGR this weekend to rule it out, but was wondering if this was possible. Seems most posts refer to poor running, non starts etc.

I thought my power steering pump was coming apart, it turned out to be the pcv. The flow to the throttle body was not high enough to keep the pcv completely open,so it flapped making a loud buzzing sound.
I sprayed some carb cleaner through the hose from the pcv to the throttlebody and it improved a lot. Now it buzzes ocassionally at idle but not above idle. Had an Astro that the pcv hose port on the throttle body completely closed from gunk sucked out of the valve cover through the pcv. (its only goal in life) I actually had to use solvent and q-tips to clean the port. (don't leave any cotton behind!!!)
Good luck!
John

Thanks for the feedback folks. Will replace the valve and clean the intake assy this weekend. Will also clean the EGR valve to see if that helps any.