On my 5.9 i have been losing oil latetly about half a quart every 3k miles. I first thought it was the plenum per what zman said there is a shiny surface on everything in there, on the pan the walls the intake manifold. It isnt dirty by any means but i know its oil.

I checked my PCV valve by reading a thread on here not to long ago because it suggested oil could be coming from it and not the plenum.. Sure enough my PCV valve was coverd in oil had oil on the outgoing part of the L section, and oil in the tube, and oil all around and inside the nipple on the intake manifold and leaking down the side.

So i replaced the valve and hose with a new one the other day. I checked it just now and again oil is in the tube, all over and inside the nipple on the manifold and on the outside end of the L part on the valve. Enough oil to coat my fingers, and almost drip out of the valve.

Why is this is happening ? Some dude on the Jeep forums said my engine is failing without giving any explaination. I wont accept an answer like that specially on a engine with only 126k on it, that runs strong, doesnt burn coolant or have and smoke out the tailpipe reved or idle spark plugs are absolutetly spotless, and has good compression of 160psi average, and 165 with oil squirts.

 

I have recently picked up a new PCV but have not installed it yet. Also new valve covers. I've got similar residue as you describe. It is alarming to me, but I won't be able to tackle it till last week of the year.

I was forwarded the following link to understand the role of the PCV. http://www.aa1car.com/library/pcv.htm

I'm still getting my hear wrapped around it, but I think it will lend a hand here. My worst thought is/are cracking. Again, I won't know till I've looked explicitly....

 

Did you remove the TB and look at the back/front of the manifold? That's the ONLY sure way of checking for oil. My intake looks pretty solid until you remove the TB and look at the pool of oil in the back...

The point of the PCV valve is to take the oil/blow-by vapors from the crankcase and put thru to the intake manifold to be burned in the engine (as well as regulating crankcase pressure). So (from what I understand) it SHOULD have oil on it, otherwise that's probably a good sign that you have no oil under your valve covers :/

As recommended by others on this forum you should always buy the PCV valve from a dodge dealership because aftermarket ones don't have the proper flow (flow to much or too little).

Check your valve covers (including the back of them) for excessive oil.
Check the oil filter and drain plug for proper install
Check your plenum--REMOVE throttle body

 

OP seems to have checked his shiz:

https://dodgeforum.com/forum/2nd-gen...um-or-not.html

https://dodgeforum.com/forum/2nd-gen...-2500-rpm.html

@Matt -- I can understand blow by vapors coming through as they should, but not actual oil. Can you explain that? B/c if that were the case, then visual inspection for the purpose of checking the plenum gasket condition could be misleading, right? Meaning...oil within the intake, as you say seems typical, has traditionally been linked to a blown plenum gasket rather than PCV normal operation.

 

Thats what im talking about what whitenuckle is saying..

Also yes i have checked the front and back of the pan. There is no oil pooling ANYWHERE on the pan.. The only oil i have in the intake is just lacing the walls, the pan, the celing ect.. All its doing it making a shiny surface, and i know for a fact the oil is coming from the PCV after i checked it from reading about it on here a couple days ago. I litterally have oil dripping almost out of the pcv valve itself, the tube has oil covering the walls of it, and when i take the tube off the intake manifold i had oil around the nipple the tube went on, and oil inside the nipple.

Im pretty sure this is where my oil is coming from. The Jeep guy on the other forum add'd more details saying its caused by excessive blow by from worn rings or seals. But i dont see how thats possible my compression numbers were normal, a barely went up with oil put into the cylinder. When i take the valve off, or the oil cap and look at the metal sheet covering the rockers which i assume is there to keep oil from being sucked up. That metal sheet has some oil on it if that means anything

Gah ths is driving me nuts.

Do you want a picture of my PCV valve ?

 

Okay so your plenums fine...nevermind.

I completely forgot to read the rest of his sentence about the PCV :/I said there should be oil on the PCV considering it is connected the crankcase filled with oil...NOT in the intake. Sorry for the confusion.
And I meant that there should be some "oil" from the vapors that pass through it, not necessarily dripping oil.

Just trying to throw out ideas since I don't know much about anything, except what I read on here.

 

Here are some pictures, im sorry i couldnt get anything better, but do you see the oil that seems to pool up on the metal plate on the pic with the oil cap removed ? Then the oil pooling up in the pcv valve when i have it removed laying on its back, then the oil on the pcv valve when its hooked up. I tried but i couldnt get a good shot of the nipple on the intake manifold but its oily too.

Oh and ignore the oil on the valve cover itself, i spilled some filling it up so thats all that is. So does this look normal ?

http://i1083.photobucket.com/albums/...2/HPIM2016.jpg

http://i1083.photobucket.com/albums/...2/HPIM2019.jpg

http://i1083.photobucket.com/albums/...2/HPIM2020.jpg

 

Mine looks worse than yours on crankcase end:

PCV is only a few hundred miles old.
And mine looks the same as yours on the intake end (no pic)
Haven't checked the intake nipple...

I thought this was all normal for the PCV valve?

 

I still think he needs to use a dental mirror to check for pooling in intake.(or remove throttle body)
These engines have a slope to them and the oil will pool toward the rear and can't see all over inside of manifold just by opening up throttle plates.

 

He posted pics of the intake on another thread...There's no oil.