Oil on valve covers

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Joep

Joep

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Hey everybody.

I've been noticing lately that after a drive in my demon, there is oil on the driver side valve cover and also on the lip of the breather.

Not so mild 440 with 850 holley dp

It seems like it could be coming out of the breather when I step on it. I drive it pretty hard and there is always more oil on the valve cover. Anyone know what's going on? It squirts out quite a bit of oil
 
Nope PVC is on the passenger side. Oils coming out of the driver side and it's on top of the valve cover so it mush be coming out of the breather I would think. I have been wrong before though....
 
I was asking if you have one installed.

Is there a baffle under the breather, inside the cover?
 
Oh sorry haha yes I do have a pcv valve on the passenger side. What do you mean by baffle? I'm sorry I'm still learningO:)
 
There should be a plate installed inside the cover under the hole where the breather is. Pull the breather and look and see if one is there. It would help deflect oil from being splashed directly on or into the hole.
 
Oh yes there is a baffle under the breather. I was pretty sure that's what you were talking about but I wasn't exactly sure
 
Does that baffle have something significant to do with spraying oil everywhere out of the breather?
 
Is the breather plumbed to the air cleaner like the factory did? Like it's supposed to be? Like it is in every single complete, correct PCV system ever from any auto maker on the planet? Or did you just get a cheap breather without a provision to route back to the air cleaner like 99% of people do? If so, then you do not have a complete PCV system.
 
RustyRatRod said:
Is the breather plumbed to the air cleaner like the factory did? Like it's supposed to be? Like it is in every single complete, correct PCV system ever from any auto maker on the planet? Or did you just get a cheap breather without a provision to route back to the air cleaner like 99% of people do? If so, then you do not have a complete PCV system.
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Not all factory PVC systems route breather to air cleaner. Just to be clear. :burnout:MT
 
Mopar Tim said:
Not all factory PVC systems route breather to air cleaner. Just to be clear. :burnout:MT
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Technically correct, but they ALL route the breather SOMEWHERE with a negative pressure, be it the air cleaner, air intake tube or wherever. That's a part of the system.
 
RustyRatRod said:
Technically correct, but they ALL route the breather SOMEWHERE with a negative pressure, be it the air cleaner, air intake tube or wherever. That's a part of the system.
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I agree that all Positive Crankcase Ventilation systems have low pressure, vacuum into the crankcase, and high, atmospheric air letting air into the crankcase, from somewhere, on older engines , usually the breather on a valve cover. And I do have the utmost respect for RRR,s knowledge on engines. :burnout:MT
 
Mopar Tim said:
I agree that all Positive Crankcase Ventilation systems have low pressure, vacuum into the crankcase, and high, atmospheric air letting air into the crankcase, from somewhere, on older engines , usually the breather on a valve cover. And I do have the utmost respect for RRR,s knowledge on engines. :burnout:MT
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Thanks. This is a simple PCV diagram I have posted before.
 

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RustyRatRod said:
Is the breather plumbed to the air cleaner like the factory did? Like it's supposed to be? Like it is in every single complete, correct PCV system ever from any auto maker on the planet? Or did you just get a cheap breather without a provision to route back to the air cleaner like 99% of people do? If so, then you do not have a complete PCV system.
Click to expand...

It's not that big of a deal to have a breather that goes to the air cleaner. Many PCV systems function just fine without it, using one that just doesn't hook up to it.
 
HP 273's up to 67 didn't use the breather tube unless it was a CAP built car. (Clean Air Package) required in California. My non CAP engine does create fumes on heavy acceleration that may be helped by the tube to the air cleaner. tmm
 
kiss said:
It's not that big of a deal to have a breather that goes to the air cleaner. Many PCV systems function just fine without it, using one that just doesn't hook up to it.
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Actually, yes it is if you don't want oil residue everywhere, which is the OP's complaint.
 
RustyRatRod said:
Actually, yes it is if you don't want oil residue everywhere, which is the OP's complaint.
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Many people have breathers that don't go to the air filter without oil on the valve covers. The cause of that is the lack of a good baffle, not the breather type.
 
Yeah I have no hose going to the air cleaner from the breather. So what I'm gathering from you guys is that there should be a hose that connects the breather to the air cleaner so that when the oil is sprayed out the breather it recycles back through the engine and is burned?
 
Two things - the reason breather filters (those are the factory breather with the big nipple on it) go to the air clraner on stock systems is because that is a source of cleaner air. Nothing to do with pressure. All it means if it's not connected its that you might want to replace it every 2-3 times you replace or clean the open element air filter.
Now - the ones you see for sale now many times have the hole under the filter element as a partially punched hole. Pull the breather out, adn look into the bottom that goes into the valve cover... If you have one that's punched in a semi-circle and slightly bent in to allow air flow, make sure when you reinstall it that the uncut side of the semicircle is oriented "up", or towards the air cleaner - not nearest the exhaust manifold/header. On really troublesome ones I'll make a mark on the breather so I know where that uncut area is. Because the oil vapor condenses in the breather when blowby overcomes the PCV suction, the condensed oil drips over the non-punched section, and drips out the exterior holes. If the cut side of the semi-circle is down, the oil will drip back into the valve cover assuming the blow by is within normal amounts.
If the blowby is more than it should be, there's nothing to do but wipe it off.
 
kiss said:
Many people have breathers that don't go to the air filter without oil on the valve covers. The cause of that is the lack of a good baffle, not the breather type.
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Then they have a piece of the PCV system missing. Period. What's so hard to understand about that?
 
This is incorrect. The valve cover breather in a proper PCV system is not open to the atmosphere. It is only vented to the air cleaner. This is the inlet for the PCV system. Look at the diagram above. It's self explanatory. Without the inlet hose to the air cleaner, there would be only a vacuum pulled on the crankcase and no circulation. Or, if using an open breather as the OP is, you get oil on the valve cover.....as the OP is. If you do not want oil all over the valve cover, switch to a closed type breather, that has the hose nipple for the inlet hose going to the air cleaner......like the factory did. Problem solved.




moper said:
Two things - the reason breather filters (those are the factory breather with the big nipple on it) go to the air clraner on stock systems is because that is a source of cleaner air. Nothing to do with pressure. All it means if it's not connected its that you might want to replace it every 2-3 times you replace or clean the open element air filter.
Now - the ones you see for sale now many times have the hole under the filter element as a partially punched hole. Pull the breather out, adn look into the bottom that goes into the valve cover... If you have one that's punched in a semi-circle and slightly bent in to allow air flow, make sure when you reinstall it that the uncut side of the semicircle is oriented "up", or towards the air cleaner - not nearest the exhaust manifold/header. On really troublesome ones I'll make a mark on the breather so I know where that uncut area is. Because the oil vapor condenses in the breather when blowby overcomes the PCV suction, the condensed oil drips over the non-punched section, and drips out the exterior holes. If the cut side of the semi-circle is down, the oil will drip back into the valve cover assuming the blow by is within normal amounts.
If the blowby is more than it should be, there's nothing to do but wipe it off.
Click to expand...
 
While it is connected to the air cleaner the pressure in the air cleaner is atmospheric. All air cleaners were/are open to the world. When there is a pressure gradient in the intake enough for the PCV systemto work the "high side" is the breather. Your own diagram shows the direction of flow. It goes from the aircleaner, through the hose (passenger side on most Mopars), into the filter-breather, into the valve cover, through the crank case, through the opposite valve cover into the PCV, and into the carb. Negative pressure is supplied by the low pressure in the manifold. Atmospheric pressure within the air cleaner pushes it into the breather. There is circulation through the crank case as long as the PCV and breathers are on opposite valve covers and the low pressure is in the manifold because one side is at atmospheric and one side is well below atmospheric. At high rpm and/or high loads there can be too much crankcase presssure for the system to deal with. That is usually accompanied by very low levels of vacuum present in the intake and very low flow through the system. So crankcase vapor gets pushed out the filter and gets everything oily & oil can condense in the filter media and drip out.
No connection to the air cleaner housing is needed. Oil drips because 1) there's too much oil in the vapor going through it at high crankcase pressures and it's condensing in the breather filter and running out, or 2) the crankcase pressure is too high for the system to deal with.
 
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