Buhk DV20ME/ Westerbeke W20 Blowby issues

[CervezaE35]

We went for a day sail not too long ago and, because my engine is old, I check it frequently when we stop after running a bit. I noticed that it had blown oil out of the top of the two nuts that hold the valve cover on. I checked for blow-by through the oil fill plug and sure enough there was a consistent puff. There was no smoke or odd smells coming and I checked the oil for fuel smells and there was non. The engine starts relatively quickly. I have not checked compression but seems to run smooth. I have discovered that there is a "venting Valve" (crankcase breather) part #0008e4177 (Circled in red) under the valve cover that is supposed to vent the extra pressure into the intake. I want to start by the easy and cheap stuff first before committing to a tear down and rebuild. My problem is that the bolts that hold it down (circled in blue) are stipped. They are Flat head screwdriver. Online resources tend to insinuate that you can clean this valve. I also have faced the issue that this part is virtually impossible to find for less than a first born child and shipping that costs more than the part itself, as most parts for this engine. I will eventually re power the boat but as I am currently learning to sail correctly and short on cash flow I would like to get as much as I can squeeze out of it. Hurray for BoatTowUS!

My question: Have any of you had any experience with cleaning or rebuilding this part? Do you know how I should go about replacing or finding an alternative for a viable price? Have any of you simply replaced the fill plug with a vent type valve and how did that help your positive crankcase pressure and is that a good alternative?

Any other recommendations or comments would be appreciated too. I searched far and wide and came to these conclusions based on my research but it has been a dead end since.

Thank you!

[a64pilot]

I know absolutely nothing at all about your engine, however every engine I have ever been around has a Crankcase breather and 99 times out of 100 you can clean them up with mineral spirits.
What happens is that they get gummed up with a waxy like substance and the mineral spirits will over time dissolve most of this gum. It may have to soak for a day or so and I'd remove the whole vale cover and soak the whole thing.
Normally you can remove and clean it.

If your engine starts well when cold and doesn't smoke up the neighborhood and has good oil pressure, I doubt I'd even consider an overhaul.
I have not yet seen a Diesel that had low compression from being worn that started well, usually it takes heat and or ether to get an old worn one going.

[CervezaE35]

Thats what I was wondering, that part in the pic, circled in red is the breather. I wasn't sure if I could just put it in diesel or spirits and that would clean it without damaging it. I would assume they would not put such a part inside a valve cover when it can be damaged by such things but I wasn't sure. Im going to try to take it off and clean it, see if it gets the job done. Thanks for the reply.

[a64pilot]

They are usually nothing more complex than a tube with steel wool or maybe a labyrinth in it. Purpose is to try to stop the liquid oil but let the vapor through

[CervezaE35]

I will post after I get it off and clean it as to what the results were for future references. Thank you for your Help!

[CervezaE35]

Finally got to the motor and it seems the pressure release valve was my issue. I got it off, dunked in diesel and the internal metal diaphragm sounds like it loosened up. No sure if the diaphragm was the problem or if it was clogged, as it turned the diesel black, but it fixed the blow-by. Thought I would update for anyone who has this issue in the past.

My current issue is that I cannot seem to find a replacement valve cover gasket that wont break the bank. Anyone have experience with something other than cork that will work and has 1/8" in thickness? I just replaced with cork and though it seems too thin (interfered with decompression lever components) it also leaked the second day.

[Sonosailor]

I had the oil problem with a Yanmar, regularly pushed dipstick out and sprayed oil out. It quit happening after another failure flooded crankcase with diesel and engine ran away! Later, a mechanic said cause was likely stuck piston rings as a result of low rpms, tidied up by diesel and high revs. Four years without a recurrence! Keep your rpms high, everybody!