I have a question about the PCV in a 1999 4.6l 2v engine. When I shut off the engine, as soon as the engine stops turning and everything is quiet, I get a rattle for a few seconds from the PCV valve. I don't have any codes, just curious if that is normal.

 

PCV no, EVR yes. They can sound like a kazoo for 5 or 10 seconds following shut down.

 

Jbrew, thanks so much for your input. Do you think the EVAP system is causing the PVC to rattle. It is definitely the PVC making the noise that I hear. You can put your hand on it and feel the vibration right after the engine stops turning (lasts for maybe two seconds). I have never noticed it before just recently. The PCV valve and hose was replaced with OEM parts two years ago. Do you think the PVC valve is defective or is that normal.

 

Sorry, that's very hard to believe. OEM valve margins are the widest of any other out there. Modulars have to breath..did you do something to it ?

Anyway, the EVR's will make noise and vibrate in hand after shut down. VERY common.

 

Jbrew, I have not done anything to the PCV valve since it was installed. The rattle I am getting may not be new, but I just noticed it in the last few weeks. The rattling sounds like it is coming from the PCV valve in the passenger valve cover and I can feel it rattle when I put my finger on it (once the engine stops). Where is the EVR valve you speak of located? I will put my hand on it and see if that's what I'm feeling/hearing. Maybe I am wrong about it being the PCV. I've certainly been wrong before.
I added a movie so that you can hear the noise that I am referring to. Thanks for your help.

 

Sounds likes a chain guide from the vid. Have you pulled the PCV valve to try and narrow it down ?

 

Chain guide was my first thought as well. However, it is quiet on cold starts and anytime its running, hot or cold. Only makes this rattle noise after the engine has shut down completely. That's why I removed the oil filler cap so I could see when the noise occurred relative to the cam shaft rotation stoppage (noise before stoppage is windage from the cooling fan). To your point, I will remove the PCV valve and see what happens. Thanks.

 

Yea it doesn't sound like it's a build up of pressure or a purge of vacuum after shut down like the EVR can. EVR sounds just like a kazoo when purging, completely normal but yeah, it isn't that.

BTW the EVR is here in front of the EGR. It opens and closes the EGR upon PCM command.



Purges vac out the top after shut down. There a foam filter under the cap that gets dirty/partially clogged. They can play a tune after shut down. The cap can be removed , the filter is serviceable. But again, that's not the noise you're hearing.

 

I don't know, that's a tough one.

 

Wow, that is good information to have. I think I recall the kazoo noise that you reference coming from a 4.2l V6 that I had years ago. It was fairly loud too. Thanks for sharing.
I will let you know what I find learn from removing the PCV valve and listening for the rattle when I get time and have someone to operate the on/off while I'm under the hood. Thanks again!!