The old elbows and tube could have heat stress cracks allowing leakage. Replace those old parts as well as the oil filler cap gasket.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

As I have already tried to make as clear as possible, the oil does NOT come from either the oil filler cap site or valve cover gasket... It comes specifically from the breather hose connection. There is also oil at the intake manifold below the air filter housing (which travels there through the breather hose) and it makes quite a mess down there...

Again, the problem is oil getting into the breather hose and leaking at the elbow connections, nothing to do with the oil filler cap or the valve cover gasket.

Thanks,
Rino

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1979 240D, W123, 105K miles, stick, white w/ tan interior.

Again, there is not the slightest trace of oil around the oil filler cap... and I have checked very accurately the elbows and breather hose around the elbows and they are dry. The oil leaks out at the very base of the upper elbow juncture... If you referred to the picture from 2005, it is quite messy and you can't really tell. But after cleaning the valve cover and adding those screw clamps a couple of years ago, the leaking is much less and it is quite clear that it comes out from exactly the upper elbow juncture - and also the lower elbow juncture - below the air filter housing - in spite of those screw clamps which are well tightened...

What I still have to understand is, is oil supposed to travel down the breather hose, or just hot gases???

If after this information I've given here you suggest I put in new elbows, I will try that as well... but again they are not cracked... the oil comes right out of the connection between rubber and metal, not from cracked rubber...

Thanks,
Rino

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1979 240D, W123, 105K miles, stick, white w/ tan interior.

That rubber does get heat stressed and hard. Hard rubber does not seal well like soft rubber. Just because you cannot see any cracks does not mean thay are not there.

The oil vapors get in there due to suction from the intake and will condense back to liquid. Hot oil flows better through the slightest openings easier than cold oil. Also check the metal for any imperfections. A slight indentation, and hard rubber ensures a potential leak.

You could also clean the area's really well and use a bit of RTV, but then that will have to be redone every time you take the valve cover off.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

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

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Why do you have oil around your filler cap? It wont be obvious that oil is leaking out of your filler cap. It has happened to me before. I replaced the elbow, still had oil around the elbow. Replaced the filler cap, oil gone for a while. The cap is cheap, gasket even cheaper. Oil comes out the blow hole whether gas or diesel. It just happens. Another possibility is that you have a blow hole that is removable. You could be missing a gasket or it could be loose.

__________________
'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

OK, I'm going to get new elbows then... If that really solves the problem, I'm going to kick myself in the ass for not having done it earlier... with the car leaking oil on the garage floor for two years... I really hope you are right about that... it would be a very easy, low-cost solution... (wondering why no one else here suggested it before)

Thank you very much,
Rino

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1979 240D, W123, 105K miles, stick, white w/ tan interior.

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

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1979 240D, W123, 105K miles, stick, white w/ tan interior.

By looking at the old picture from 2005, you can't tell where the leak is from... oil in that photo is all over, even near the oil filler cap. But after I cleaned it and installed the screw clamps two years ago, there has been no oil at all anywhere near the filler cap. The oil is very clearly leaking as I said. This is also evidenced by the same exact thing happening at the lower breather hose elbow. However, time will tell if you are right. I will report right back here as soon as I install the new elbows.

Thank you very much,
Rino

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1979 240D, W123, 105K miles, stick, white w/ tan interior.

How much blowby does the engine have?

The gaskets were really designed to be liquid tight, not really air tight, as new engines typically have no blowby.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

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

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

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

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

You know, I am not sure that it has any blowby at all... as I said earlier in this thread. Later someone insisted that if I get oil out of that juncture, then I MUST HAVE blowby, so I went along with that assumption. However, I have none of the symptoms, to my knowledge, that were earlier in the thread associated with blowby...

Is there a way you can help me diagnose whether I have blowby or not?

Thanks,
Rino

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1979 240D, W123, 105K miles, stick, white w/ tan interior.

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

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1979 240D, W123, 105K miles, stick, white w/ tan interior.

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...

__________________
1979 240D, W123, 105K miles, stick, white w/ tan interior.