It's been on my list for some time, finally did it:

Mercedes Valve Cover Breather

You may be surprised at how much complexity was involved in this design. I'm quite sure that Rube Goldberg was inspired by a Mercedes.

I think I have mentioned before that German Engineers were slightly ' OCD '.....
which we benefit from....

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

In looking for a solution other than buying a brand new valve cover, I'm considering using the oil separator from a BMW, which is was obviously designed by an engineer, not a cartoonist. Here are some photos.

The first thing you notice is that this is a part designed to be bolted to the OUTSIDE of the engine, what a concept. You can buy these for as little as $15, although the genuine part costs about $50. Still a lot less than the hundreds required to replace a Mercedes crank breather.

The design is similar...blowby enters at the bottom and the geometry of the part forces it to swirl around the conical enclosure. This forces oil out along the walls, where it drips back into the sump. The gasses then move upwards, where they impinge on the diaphragm. The diaphragm mechanism is identical in function to the Mercedes part, down to a small pinhole on the outside of the enclosure. The diaphragm is about 2mm smaller, otherwise it could be used to repair the Mercedes part.

Plumbing would be a bit ugly, but it could be installed externally on a 60x. The problem is that the spring is twice the strength but half the length of the Mercedes part. I'm not sure if it will work or not, and I'm not sure how to experiment without risking the motor.

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Thank you so much Maxfrank that has been on my mind for at least 10 years. The ML gasers have a similar design but some folks and I can't recall how have suggested a fix which seems to work as they claim but I'd be concerned about some fastener dropping or other leak points. I'll have a look and post if I can find it.

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92 e300d2.5t
01 e320
05 cdi
85 chev c10

the OM606 engines have the separator/breather doughnut chamber outside the valve cover as a replaceable part.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

I'll have a look at the 606. What really bothers me is that I can't inspect or test the part that's in the car. I know I have oil in the accordion tube, but I have no way of choosing a solution. It could be that the oil is normal, or the result of some other condition. Or it could be that the diaphragm is petrified. The only way I have to test now is to replace the valve cover with brand new, an expensive test. I'm hoping that an external valve from another type of engine can be adapted, even temporarily.

Is this the 606 gadget? How does it work?

Mercedes W124 95 E300D 6CYL Diesel Under Hood Plastic 1 Valve 6060100091 | eBay

It looks like the diaphragm on the bottom is exposed to pressure inside the valve cover, and opens a valve. Is that right?

This is the thread I had in mind only similarity is reattaching the baffle and it appears more meat is on this valve cover.

how to remove valve cover baffles (how to clean your valve cover) - evolutionm.net

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92 e300d2.5t
01 e320
05 cdi
85 chev c10

Different car, much simpler oil separator. In his position, I would have just filled it with solvent and washed it out.

The problem with reassembly is the rivets. If any of those fasteners vibrate out, your engine is toast. JBWeld doesn't cut it, especially in a Diesel. If I was going to reassemble a separator, I would have a good shop tap the holes to a grade 4H tolerance, and use Locktite 272 for further safety. It's moot, because there are no available replacement diaphragms.

Would you tell me the size of the 2 small holes or the inlet to the seperator please. I ask because based on the advise of another website MS he recommends to break off the vent tube connector to install another fitting to stop oil weeping. This would likely cause a greater amount of vapours to be drawn out compounding the amount of oil found in the intake. I would think the smaller holes cause an increase in vapor velocity which aids in vapor/oil separation.

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92 e300d2.5t
01 e320
05 cdi
85 chev c10

The two holes are each 10mm. If I was going to try one thing to reduce oil infiltration, I'd cut off the J-bend in the drain, but since I don't understand why it's there and the mod is not reversible, I hesitate. There doesn't seem to be any way to solve the problem of replacing the diaphragm, which is almost certainly close to toast in every running 60x out there.

I won't make any speculative guess as to how the flow works in this contraption. There is so much you can't know: what is the open volume of the crankcase? What is the rate of blowby production? How does windage affect crankcase pressure? How much vacuum is generated by the intake, and under what conditions is it created? Are there any penetrations in the engine jacket that add air flow (such as a vent in the oil cap, or a bad crank seal)? What is the activation pressure of the diaphragm/spring combination? Why is that oil drain located under the vacuum source? Why does it have a j-bend?

My sense is that there was once an engineer who thought this through based on meticulous measurements. Maybe he made some mistakes, or maybe not. Never bothered to document the design concepts. And then it was repeated as past practice, without further thought, for twenty years. All I know is that I've never seen a PCV valve that's not designed to be serviced.

Great post. I've always wondered what was hidden inside the valve cover...

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Here's a good write up on design considerations for breathers and oil separators, just to emphasize that it's not a design to mess with lightly:

http://www.dana.com/wps/wcm/connect/897e0128-2bb5-4371-b991-1c6678c06c25/DEXT2-Publ-MTZ__Oil_separation_e.pdf?CACHEID=897e0128-2bb5-4371-b991-1c6678c06c25&CONVERT_TO=url&MOD=AJPERES

One hose barb connects to the valve cover with an L shaped elbow, the other side then goes to the intake manifold breather holes where a negative suction is applied to them.

The turbo 606 has the suction side plumbed to the intake tube of the turbocharger like your 603

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

I get that, but this can't be just a hose connector...how does the valve work? Is this a diaphragm on the back side?

http://i.ebayimg.com/00/s/MTIwMFgxNjAw/z/IWoAAOSwkNZUgqxI/$_57.JPG