Help needed to identify nature of oil leak problem

[rino]

I would have done a preliminary search before posting this had I known what keywords to use... I'd appreciate your help in identifying the nature of the problem at hand.

The problem concerns a 1979 240D.

There's oil leaking (it has for the past three months, since I got the car - but lately it's gotten much worse) from what I assume to be the PCV system (I am referring to the pictures from my Haynes Diesel 123 Series manual. However, the configuration in my car differs from what is shown in the manual pictures).

The oil leaks out from the connector on top of the crankcase, right next to the oil filler cap, and the problem apparently is a loose hose connection. What really surprised me, though, is that, upon looking more closely, I noticed that the other end of the hose doesn't connect to anything, but just hangs in the open under the air cleaner box. Why would oil come out of a ventilation hose that, as far as my understanding goes, is supposed to convey just burnt gases? Besides, the other hose, the one attached to the connector on top of the air cleaner (which is identified in my manual as the PCV ventilation hose and is shown connecting to the connector next to the oil filler cap) attaches somewhere else in my car (instead of going to the connector next to the oil filler cap, as shown in the Haynes manual). I find it very confusing and am trying to understand which is which.

I'm planning to lift the air cleaner box in order to see if there is a connector hidden under it where the loose hose should connect... Please let me know what you think.

Rino

[rino]

Here's a picture of the connector that leaks oil.
It's the one just above the oil filler cap.

Please respond and let me know what you think.

[leathermang]

Under the valve cover you have an oil line running along the cam.. it is squirting oil onto the cam lobes... so in all that air space under the valve cover you have oil being flung about..
In the old days valve covers had ' breathers' on them which was just an opening to the air but with something like brass wool in it... which would accumulate much of the oil and let it drip back into the engine...
Then Clean Air happened and they started taking those fumes and re burning them ... so this tube just goes to the air filter so those oil laden fumes can be sucked back through the engine and exhausted at the tailpipe...
You need to fix that junction between the rubber line and the valve cover.
It does not look to be original... looks to have a hose clamp on it... I think originals are available..
Also renew your gasket on your oil filler hole cover... and when you open that be sure to never turn it upside down... as oil will run into the top and then onto the valve cover when you put it back on...

[J. R. B.]

Now I know why I always had oil around my filler hole after an oil change. Thanks for the tip Leatherman I learned something new today.

Take off your air cleaner and look for the port where it is supposed to connect to the intake manifold.

If this is disconnected and not properly blocked off..your engine is sucking dirt strewn air in that hole (bypassing the air cleaner).

The system on that 240D is simple and only has 2 rubber elbows and a hose. It just blows the air from the valve cover over to the intake and burns it up. The later 5-6 cylinder models are much more complex as they capture oil/oil vapors and return the liquid to the oil pan while offing the air into the intake. (Ideally )

[rino]

Originally Posted by Brandon314159

Take off your air cleaner and look for the port where it is supposed to connect to the intake manifold.

If this is disconnected and not properly blocked off..your engine is sucking dirt strewn air in that hole (bypassing the air cleaner).

The system on that 240D is simple and only has 2 rubber elbows and a hose. It just blows the air from the valve cover over to the intake and burns it up. The later 5-6 cylinder models are much more complex as they capture oil/oil vapors and return the liquid to the oil pan while offing the air into the intake. (Ideally )

Thanks for your input.
Actually, I fixed the problem this morning by securing both ends of the ventilation hose to their relative ports by means of two large screw clamps.
And yes, as you say, the hose was disconnected from the lower intake port.
My guess is, it had been for over three months, during which I have put over a thousand miles on my car... I'm lucky the car has been running flawlessly.
However, the problem is now taken care of, as there is no more oil/smoke in sight.

Also, thank you, leathermang, for the info.

[Dropout]

Originally Posted by Brandon314159

Snipped for brevity

The system on that 240D is simple and only has 2 rubber elbows and a hose. It just blows the air from the valve cover over to the intake and burns it up. The later 5-6 cylinder models are much more complex as they capture oil/oil vapors and return the liquid to the oil pan while offing the air into the intake. (Ideally )

What kind of baffle etc. is on the inside of the valve cover? Can it fall out?

[vstech]

yup, sounds normal to me.
there will always be oil vapor in the gasses. modern vehicles have an oil accumulator in the circuit. the rest of us, have to burn it.
go with new elbows and report back. if they work for you, I will get some for mine.
John

[rino]

Originally Posted by vstech

yup, sounds normal to me.
there will always be oil vapor in the gasses. modern vehicles have an oil accumulator in the circuit. the rest of us, have to burn it.
go with new elbows and report back. if they work for you, I will get some for mine.
John

John... so you have the same problem and want my car to be the guinea pig... which is fine by me... I hope rrgrassi is right, easy solution if it works. I'll report back as soon as I install the new elbows.

Rino

[vstech]

Originally Posted by rino

John... so you have the same problem and want my car to be the guinea pig... which is fine by me... I hope rrgrassi is right, easy solution if it works. I'll report back as soon as I install the new elbows.

Rino

yeah, mine looks pretty much like your first picture. I will seal it up with RTV soon, and see if it clears up all the oil.
that ought to verify for sure if it will solve the problem.
John

[rino]

Originally Posted by vstech

yeah, mine looks pretty much like your first picture. I will seal it up with RTV soon, and see if it clears up all the oil.
that ought to verify for sure if it will solve the problem.
John

I have to say that mine lookED as in my first picture only until I installed the screw clamps on the breather elbows. The clamps really minimized the leak problem. All you can see now is just a bit of oil at the base of the upper breather elbow, and that oil travels down the left side of the camshaft cover making, over time, a mess on both the bottom of the engine and the garage floor. How do your breather elbows look? Do you have an idea of when they were last replaced?

Rino

[The Gears]

Thanks Leathermang for the oil filler tip. You have no idea how much time i have spent changing the gasket on the filler cap.

[rino]

Originally Posted by The Gears

Thanks Leathermang for the oil filler tip. You have no idea how much time i have spent changing the gasket on the filler cap.

I hope leathermang comes back soon... he hasn't been around for a while.
I just re-read that particular post of his you are referring to, from 2005... and he gave me the right advice back then, it seems, after all...