Crankcase Oil Contaminating Yanmar Diesel Fuel

[skipperpete]

Originally Posted by Compass790

Thanks for the kudos skipperpete, means a fair bit coming from you.
Think I only got it scenario 1/2 right as it appears the excess crankcase pressure is not needed to get the issue. Still it was close.

It was post #6 my slightly educated guess. Still scratching my head how it's not the usual diesel in the sump diaphragm failure telltale.


Enjoyed the thread made better by swordds descriptive feedback.

Well I’m really happy to hear that there’s no blowby, and maybe the 3YM is unique in that the lift pump is below the cambox oil level on the injector pump so a diaphragm fail is always going to drink lube oil....Beats me!!

[Compass790]

Originally Posted by skipperpete

Well I’m really happy to hear that there’s no blowby, and maybe the 3YM is unique in that the lift pump is below the cambox oil level on the injector pump so a diaphragm fail is always going to drink lube oil....Beats me!!

I guess it must be to do with the construction being on the side of the injection pump as you say, lift pump partly below possible oil level looking at drawing but I need a real live 3YM20 to look at to puzzle it out/ or not

Just pleased sworrds got it sorted.

[Uncle Bob]

Originally Posted by Juggerknot

Have you checked the level in your crankcase?? If you are loosing oil to your fuel system you'll surely be low...Keep us informed, want to see the resolution of this head scratcher...

Had you tried reading the whole thread you would already know.