Very strong vacuum through oil fill tube
#1
Very strong vacuum through oil fill tube
My ls1 just started missing the other day and then feels like it is completely missing a cylinder now. I just checked my spark from the coils and they are fine. It used to have quite a bit of blowby but now there is such a strong vacuum you can hardly get the oil fill cap off and it will suck your hand to it. What is going on?
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#5
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Have you checked your PCV system and made sure it's not goobered up.
Any recent maintenance or mods doen to the car?
Also you may have some internal issues like perhaps a broken ring land.
Any recent maintenance or mods doen to the car?
Also you may have some internal issues like perhaps a broken ring land.
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#8
ya this car hasnt been driven very far one way for a while after the engine swap but the first time I drive it about an hour and a half and then it starts doing this out of the blue without ever getting on it hard. There is no smoke or knocking sound and now I started it up this morning and it wasnt missing, but I didnt get to go drive it (still on trailer).
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If You have strong vacuum in the engine that is what You want and the pcv could'nt be clogged . That is exactly the purpose of the pcv is to create a negative pressure in the crank-case not allowing oil to make its way past the piston rings and not much or no oil can leak out gaskets and seals in that condition , but yes it could be exessive which can pull some of the fuel and air past rings and eventually thin You're oil . Could'nt be pcv stuck open , there is'nt that much opening where pcv hose goes into tb
Last edited by chrisfrost; 08-27-2011 at 08:01 PM.
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PCV valve is supposed to be a volume metering device, not a pressure
regulator. If youhave a tight motor and no blowby it might well draw a
pretty strong vacuum.
But if it's flowing so much that it messes up idle, that's not right. Shake
it (PCV valve) and it should rattle.
regulator. If youhave a tight motor and no blowby it might well draw a
pretty strong vacuum.
But if it's flowing so much that it messes up idle, that's not right. Shake
it (PCV valve) and it should rattle.
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The main purpose of the pcv valve is to vent positive crankcase pressure(open) and retain negative crankcase pressure(closed) so that there will be no positive pressure to push oil past the rings