How to test PCV valve?

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My car is burning 0.8 qt of oil every 1k miles, I have checked the PCV valve, it isn´t blocked or dirty, I can hear a sound when I shake it which tells me that is in good condition. I can suck from the Intake Manifold very easily, Shouldn´t it require some vacuum pressure to open? And I can also apply pressure with my mouth from the intake manifold side and the air can pass the PCV valve but slowly.

The car is idling at 800 rpm which convinces me that the PCV valve isn´t stuck open.

What do you think?
 
If its cheap to replace where you are just replace it. They are about 10$ here (less in USA). Worst case you are out some cash. Mine seemed normal but once replaced the slight oil usage stopped. Seems like a good amount of consumption though.
 
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Instead of sucking on the hose, do you have good vacuum from that hose when the engine is idling? You should.
 
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If you do replace it, I would go with an OE part. I learned the hard way that the only way to go with a PCV valve is OE.
 
They're just a check valve. Flow should only go one way, towards the intake manifold. During periods of slight positive crankcase pressure (wide open throttle, etc), the valve should close.
 
Originally Posted By: demarpaint
If you do replace it, I would go with an OE part. I learned the hard way that the only way to go with a PCV valve is OE.


+1 OE is a good way to go. I would replace it anyways. It traditionally isn't an expensive part.
 
I just bought a Subaru OEM PCV for my FXT and it was $8 before shipping.
The bad thing is that I have to pop the intercooler off to get to it...this is the reason a local dealer totally blew off replacing it at my 60kmile service after I had been assured on the phone that it would be done. They pointed to an "if applicable" line in their standard paperwork for the service, I was stupid enough to read this as meaning if the vehicle had one and not if the techs felt like doing it. Gotta get this stuff in writing when dealing with shady dealerships...
 
An oil with a lower NOACK value should slow that oil consumption rate, or switching to a 10W-30 (assuminb you're running 5W-30 now) will prob help.
 
Originally Posted By: demarpaint
If you do replace it, I would go with an OE part. I learned the hard way that the only way to go with a PCV valve is OE.


I agree. I hate using plastic parts, but I replaced a metal aftermarket PCV valve with a plastic Motorcraft PCV valve, and my car idles better. The difference is that the aftermarket PCV valves seem to let some air both ways, so it's like having a vacuum leak. The OE one only let air in one direction. Still cheap enough too (Motorcraft part bought off eBay, or Amazon).
 
Originally Posted By: Emanuel
My car is burning 0.8 qt of oil every 1k miles, I have checked the PCV valve, it isn´t blocked or dirty, I can hear a sound when I shake it which tells me that is in good condition. I can suck from the Intake Manifold very easily, Shouldn´t it require some vacuum pressure to open? And I can also apply pressure with my mouth from the intake manifold side and the air can pass the PCV valve but slowly.

The car is idling at 800 rpm which convinces me that the PCV valve isn´t stuck open.

What do you think?


The spring can fatigue and cause it to pass too much flow. This can contribute to consumption. Replace it and monitor oil level

My car was up to about a qt in 2k mi. I changed the PCV and now I'm
Back to about a qt every 6k mi
 
Originally Posted By: The_Nuke
An oil with a lower NOACK value should slow that oil consumption rate, or switching to a 10W-30 (assuminb you're running 5W-30 now) will prob help.


I´m currently using a 15w40 HDEO
 
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