vacuum in the crankcase
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From: FL
vacuum in the crankcase
Hi, I found I have extreme Crankcase Vacuum when engine is running,,, You can not take off the oil cap and there is a loud sucking coming out of dip stick and carb's... I have checked the PVC (2) and they raddle... I have Check vacuum lines do see any problem...Does anyone have any knowledge in this problem 84 C4...
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From: FL
I built this car out of 3 vettes the engine is all stock there was 2 PVC's in it always that i no about... But the car has been running prefect up into,,, I don't no lets see 2 weeks i seen a puff of smoke n the smell was getting worst then last Thursday i heard the dip stick noise was suck so i pull the oil cap n i could not get it off... when i did i put my hand over it n it sucked my hand down... So i started to look up crankcase vacuum...Everything say's PVC system... But the PVC raddles So i will pick up new PVC today... So still don't no whats going on
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From: Lufkin Texas
My point was that the passenger side valve cover needs to be open to the atmosphere so air can enter the crankcase. This is to avoid a suction in the crankcase. If there is a PVC valve in that line, the air may not go into the crankcase to replenish the air sucked through the driver side PVC valve.
Is there a PVC valve on the passenger side valve cover?
Ken
Is there a PVC valve on the passenger side valve cover?
Ken
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From: FL
Yes the passenger side valve cover does go to the air cleaner but it has PVC... LIke i said 1 or 2 PVC's the car has been running fine for a year an a half with the 2 PVC's so..My crankcase vacuum problem just started 2 weeks... So the 2 PVC's did they go bad or is my crankcase vacuum problem something else??? Thanks Ray
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From: FL
My point was that the passenger side valve cover needs to be open to the atmosphere so air can enter the crankcase. This is to avoid a suction in the crankcase. If there is a PVC valve in that line, the air may not go into the crankcase to replenish the air sucked through the driver side PVC valve.
Is there a PVC valve on the passenger side valve cover?
Ken
Is there a PVC valve on the passenger side valve cover?
Ken
Last edited by rays96in; Jun 19, 2013 at 10:11 AM.
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From: FL
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From: Lufkin Texas
It probably idles fast because the hose goes from the intake manifold to the passenger side valve cover. When you removed the PVC valve,you made a big intake leak. The hose should go to the air cleaner, not the intake manifold.
Hope this helps,
Ken
Hope this helps,
Ken
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From: FL
Yea mine comes from the can by the FRT. headlight to the PVC in Vavle cover on drives side and follows though to manifold... Then passengers side goes to air cleaner.. Right..
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From: FL
I just took off all smog pollution crap do I still keep the can in frt. drives side that goes to the pvc in valve cover... But I see in your setup that u don’t have PVC on drivers side yours goes straight to manifold..
Melting Slicks
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If you pull out both the breather and PCV valve, (I've never heard of a car having more than 1 PCV valves) and place your hand over the holes and there is still vacuum being drawn, it is possible that you have a leaking ring(s). If there is still vacuum, perform a compression and leak down test on each cylinder. Take your results and go from there.
