[zaf_uom]

Hello,

Can someone please tell me if a PCV valve is supposed to rattle a little if I shake it along the axis of the valve? I just took mine out of the vehicle (OEM) and it rattles just slightly. Functionality wise, it allows compressed air to go only in one direction and block the other direction.

I would like to know if it is time to replace it.

Thanks

 

[sdspeed]

when you shake a PCV is SHOULD rattle. The spring is quite weak so that only a slight pressure in the crankcase or slight vacuum from the manifold will open it.

 

[zaf_uom]

Perfect. That is what I wanted to know. I'll put it back and call it a day.
Thanks sdspeed.

 

[kevcules46]

Yes, they are supposed to rattle. If you remove it , take some brake cleaner and spray inside it to clean it out. It should rattle easier now, the valve being more freed up. If in doubt, change it, they are not expensive at all.

 

[zaf_uom]

Yes, they are supposed to rattle. If you remove it , take some brake cleaner and spray inside it to clean it out. It should rattle easier now, the valve being more freed up. If in doubt, change it, they are not expensive at all.

Thanks. That is exactly what I did after sonicating. It looks much better but also rattles more.
I considered buying a new one but from what I read, there are 2 types of PCV valves for the 9th gen corolla (2 different thread spacing) and that is why I did not get a new one.

Thanks for your always helpful advice.

 

[Supersonic]

Pcv also has a spring that is calibrated, so eventually you may want to get a new one. I think the fastener is either SAE for example 3/4 inches, or Metric like 24mm, that how you can also tell the difference.

 

[puremetal89]

If the pcv does not rattle that indicates a problem. However, just because it does rattle, doesn't mean it's sealing efficiently. As mentioned they are cheap enough, and considered a tune up item. Replace if you suspect it or doing tune up maintenance.