Actually I wanted to know the sort of set-up I suggested reduced or stopped the Oil Leaks as some articles claim.

I pretty much solved my Blow-by issue that contaminated my Air Filter:
Washable Air Filter and Intake Mod , With Larger Breather
http://www.peachparts.com/shopforum/showthread.php?t=280376

I could use a better Breather/Filter but don't know when of if I will ever do that.
This thread has already brought out some ideas.
A larger vent hole (most likely using the Oil Fill Cap hole) would not only decrease the Crankcase pressure but would decrease the velocity of the Blow-by and make it easier to separate the Oil from the Vapor (the Breather/Filter acts as an expansion chamber to do that and I suppose there is also some cooling effects).

That's what I mean by an oil separator. Run the line into a jug and another line out of the jug. There'll be a vent to atmosphere and the oil can drop into the jug.

A vent to the Atmosphere does not guarantee a low Crankcase pressure between the Outlet Hole in the Valve Cover and the Crankcase.
The Outlet Hole has to be large enough to prevent a pressure build up in the Crankcase.

Holy crap!

7 seconds to bog down...

Hmmm I'll give it some thought.

As for the crankcase pressure effecting the vacuum pump.

Assuming you've got a piston pump => I can imagine that it would be harder for the pump to push against the crankcase pressure. If the non return valve in the vacuum pump was leaking then I can imagine that the piston assembly would be pushed back towards the engine so that the bearing race is always in contact with the bearing track on the front of the timing device. I think the crankcase pressure would reinforce the spring pressure in the piston vacuum pump.

Back in the early 2000's there were lots of threads comparing the length of time it took for the engine to shut down when the elbow was occluded. I think people finally stopped experimenting because the comparisons weren't worthwhile since the length of time was dependent on the condition of the seals in the engine. Good seals=quick stop Bad seals=slow stop. I think the garbage bag blowby standard evolved out the failure of the 'how many seconds to shut-down test'. MB does make a tool for measuring blowby but I can't recall anyone on here ever using it.

Does plugging the EGR valve with these kits we see have much affect on this topic? I am cleaning the intake and was planning to do the EGR block off plate thing....but not if it will increase the risk of creating leaks down the road.

I can't see the EGR having much effect on things.

Is there any empirical data documenting what crankcase pressures might occur at any time the engine is running. The breather from the valve cover is basically open to the atmosphere, even though it's routed into the air cleaner. Should be pretty easy to install a guage somewhere in the plumbing to get some idea of what pressures actually occur.

The Gauge has to go on the sid of the restriction that would hold pressure; the Engine side of the exit Hole in the Valve Cover.
A good place to install a Gauge would be to get another Oil Fill Cap and modify it for a Gauge hook up.
That would leave your Crankcase Breather system un-altered and give a true reading.

Blocking off the Hole completely allows the crankcase to build up to the Point that the Engine will Shutoff.

On one of the Forums ForcedInduction said if you do it long enough you could damage Seal/s.

I have a way to update the Bag standard.

In my Brief Career as a Respiratory Therapist at the one Hospital they used special Bags marked in liters to measure the exhaled Volume of the Patient when they used the Old Bird Type IPPB Machines.

I don't know where to get any and have never tried look for them.

What surprised Me about them using the Bag is that other places would have used a Spirometer (a type of Flow Meter) to do the measurement.
But, I do not think a Spiometer and Oil Vapor go well together.

The shuttoff issue does not have to do with the Vacuum Pump.
It has to do with the fact that the Fuel Injection Pumps Camshaft and Governor Housing are connected to the Crankcase and exposed to the Crankcase Pressure.
One side of the Vacuum Shutoff Diaphragm is esposed to the Crankcase Pressure that is in the Fuel Injection Pump Governor Housing.
If the pressure inside of the Housing rises enough it pushes the Diaphragm the same direction Vacuum would pull it if you applied Vacuum to it and can shutdown the Engine.

Oh right - sorry I misunderstood what you meant.

Very interesting problem for the Mercedes Myth Busters here. I like it! The more we talk about these cars the better we get to understand them - we get to a stage where we think we've seen it all before and wham bam! here comes another little idiosyncrasy.

Technically the suction through the existing leak of the rear seal should reduce or eliminate it to an unknown degree. This would mean a continious vacuum state in the engine would have to be sustained..

How much of a pump might be required in capacity to achive this really an unknown and could be variable or substantial as well. Depends on how much deficiency is present with the present rear main seal as well.

You will probably have to incorporate a good oil seperator as well.

As tough as it is I would change the seal instead. All the fumes produced would have to be carried to the rear of the car I suspect to avoid making passengers sick is another concern. I was even thinking of a venturi effect but not practical at low speeds.

I've been reading though the FSM trying to find out more about the return flow of oil from the IP.

Chapter 18-005 in both the turbo and non-turbo FSM versions don't help much. The only mention I can find about the return is in chapter 7-010 showing the "new" oil fed injection pumps...

...Oil goes in via the intermediate shaft and returns "to the crankcase" - how it gets there and the path it takes isn't clear in the FSM. I'm going to have to take my engine to bits again to see!


Even so for the crank case pressure to effect the diaphragm at the end of the IP the crank case pressure would have to be greater than the oil pump pressure...

...wouldn't that cause lots of other lubrication problems within the engine? Jets on the turbo OM617 version would have trouble spraying oil up and into the bottom of the cylinders for example.

Now I don't know by how much the oil pump pressure gets reduced by the time it reaches the IP (and crawls its way though the small path way through the intermediate shaft) - I guess that needs to be measured - but how?