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| Forum name | Turbo/Nitrous Tech |
| Topic subject | valve cover breather question |
| Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=82126 |
82126, valve cover breather question Posted by baxsom, Feb-02-05 03:47 PM
ok i have researched a ton of posts on a breather on your valve cover nipple. most of them end with "just get a catch can"
my problem though is if i try to do a boost leak test i have to plug the VC nipple for the system to pressurize
if i put my finger over the nipple and pressurize the system it holds pressure but as soon as i take my finger off whoosh air comes out of it and the system depressurizes
is this normal?? or does it mean that my pcv valved is dead
or worse
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82136, RE: valve cover breather question Posted by ForceFed420a, Feb-03-05 01:20 AM
PCV is shot.
It should be a one way valve, and when there is vacuum in the manifold, it opens to vent the crankcase into the intake to evacuate gases and stuff like that. So, in other words, stuff can go from the crankcase to the manifold, but not from the manifold to the crankcase.
If the crankcase is seeing "boost", that check valve is not working. I'd start there and see what happens.
Brian
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82145, RE: valve cover breather question Posted by baxsom, Feb-03-05 03:12 AM
could it be possible that it was installed backwards because when i replaced all the rubber vacuum lines with silicone i replaced that large line from the valve cover to the manifold and replaced the pcv valve at the same time
i thought i put it back in the way it came out but just to make sure going from the manifold to the VC should you be able to blow air through it or not because i took it off and if your blow air from the small end that was going into the intake you can hear the check spring inside closing but air still goes through
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82147, RE: valve cover breather question Posted by ForceFed420a, Feb-03-05 03:31 AM
You should be able to blow through it one way, and not at all the other way. Install it so that air will be able to flow from the crankcase (VC) to the manifold.
Something to keep in mind. If you try to blow into a boost gauge, you'll realize that you can only blow maybe 2-3 psi. Your turbo is pushing much more than that.
Even if there's a little leak, you should replace it.
Let me know what you find! Brian
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82208, RE: valve cover breather question Posted by baxsom, Feb-03-05 04:22 PM
good call on the pcv valve i took it off and from the manifold to the intake air would blow through easily
from the intake to the manifold the check ball would close but air would still go through i went to the local autozone and picked up another pcv and tried it and this time no matter how hard i tried (and i imagine it was quite comical to watch) i couldnt get air to go through from the intake to the VC so hopefully this fixed my problem
it must have just went bad because there was no oil on my vc vent breather
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82215, RE: valve cover breather question Posted by ForceFed420a, Feb-04-05 02:48 AM
haha!! yeah, I bet that looked pretty funny :)
I'm sure that's what your problem was.
Glad I could help.
Brian
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82222, RE: valve cover breather question Posted by whodatt1, Feb-04-05 05:42 AM
I kept blowing those valves up. so i juse tended up pluggin that port from the intake manifold. and routed the two lines from the valve cover to a catch can.
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82237, RE: valve cover breather question Posted by baxsom, Feb-04-05 08:52 AM
that is probably what i will end up doing because i put the bad pcv valve on about 6 months ago and it is already bad so when the new one goes out i will just put a catch can inline
between the valve cover and the manifold
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