Oil from the Crankcase breather - Yanmar YSB8

[Duncan Maio]

On motoring passages (like yesterday's run to Newport - dead on into 20 knot winds against the tide in the fog) where the engine is run long and fairly hard, we get lots of oil out of the crankcase breather hose (we finished the 4-hour trip almost a half-quart low, with oil all over the engine pan). The boat has no tachometer, so I have no idea if we are running too fast, but we were only running about three knots and habitually we reduce throttle if the exhaust starts to smoke excessively.

Any thoughts on stopping this problem?

Duncan Maio
CD 27 #37
s/v Remedy



dmaio@meganet.net

[Mark Yashinsky]

Double check that the crankcase is not over filled. Is the dipstick truely all in way in and not hung up on something??? Its very hard to see in the engine compartment on a CD27. Next, isnt the breather suppose to go back into the air intake so the fumes can be burned??? Is this a high hour engine (more crankcase blow by)??? This is best left to a professional or someone who has invested in a diesel compression gauge or blown down gauge. Does the breather have (or suppose to have) a pcv valve to control this. How far open is the trottle, 1/4 way, 1/2 way, 3/4, ALL THE WAY??? Rough gauge on rpm. Get the engine shop manual and check the breather hoses and see if it had a troubleshooting section.

[Duncan Maio]

Thanks for the tip - it appears that I have misread the dipstick and the engine oil may have been slightly overfilled instead of mostly down. My dipstick has a pair of marks separated by a ".6L" marking, which I mistook for the high and low marks, and a cross-hatched area below that. THe manual (on my desk, not on the boat) indicates that the cross-hatched area (below that pair of marks) is the actual high-low range.



dmaio@meganet.net