If it rattles freely its good. Right or wrong? And.....what makes them go bad?
PCV valve test?
- Thread starter NCGuy68
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I don't know if you can use the 'rattle' test as an end-all for PCV valves. I think there still needs to be a certain spring tension for the valve to function properly. The valve can rattle but have too low a tension and let too much air through. JMHO
As far as them going bad..I would imagine either getting gummed up or the spring becoming weak from time/use. Again, JMO..
As far as them going bad..I would imagine either getting gummed up or the spring becoming weak from time/use. Again, JMO..
Rattle test can only prove that your check ball/check plunger portion isn't stuck due to varnish. It doesn't provide conclusive evidence as to whether the metered orifice is not clogged nor the spring loses it's tension...
when in doubt, simply replace it with a factory OE one for proper emission specifications.
when in doubt, simply replace it with a factory OE one for proper emission specifications.
Hold your hand over the oil filler hole as the engine is idling. If you feel a suction against your hand, then your PCV needs replacing. If you feel no suction, then you're alright.
Merkava = wrong.
Your crankcase shouldn't be under a vacuum if the breather is working as it should. Your PCV valve is a flow metered check valve. You should be able to suck air through it (normal flow path), but not blow air back the opposite direction. The check valve should move freely.
Joel
Joel
correct. and it should move freely with NO hesitation. the one i pulled off the civic at 110k, you could blow shut but it had a hesitation due to the sludge it was filled with. $20 and a few curse words later, the new OEM Honda PCV valve was in place, gaining me 2-3 mpg on the highway.
I'am confused, please explain what one should feel if the valve is working properly.
Craig, at idle, you should feel a strong vacuum at the tip of the PCV valve. You should not feel 'suction' at the oil filler opening. (AKA, 710 hole
Joel
A more sophisticated test, but not any better, is too see if the PCV will hold a business card at idle. There should be a spring loaded plunger that moves freely, and some small amount of force should make the plunger move. Buy a new one, clean the old one and see if it behaves the same, if it doesn't then replace it, otherwise you now have a spare.
Bad things happen when PCV valves aren't working properly, they're cheap, usually last quite awhile, so feel comfortable in replacing it once in awhile.
Bad things happen when PCV valves aren't working properly, they're cheap, usually last quite awhile, so feel comfortable in replacing it once in awhile.
a better way to handle this is to go buy an OEM PCV valve...
if you have to, buy a Purolator....but I recommend OEM.
if you have to, buy a Purolator....but I recommend OEM.
Merk - That does nothing to test a PCV valve. It can be stuck open closed, or in between, with varying results at the oil fill opening.
You are wrong, despite your '5 million' references.
You are wrong, despite your '5 million' references.
I bought one from R&S strauss it rattle beautifully. I blew into one side and air flowed very nicely. then did the same to the other side and it flowed "hissingly". I tried the same with my stock pcv and it did not rattle or leak. I just put it back in. Was changing it for good measure, but seems the after market stuff sucks. Buy OEM.
unDummy - Sounds like a plan! If #@$%! miracles it back on out of the trash, who are we to argue?
This makes sense....
Does everyone agree with this simple test?
I agree with this test....
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