oil leak

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mibrinn

oil leak

Post by mibrinn »

I have a Yanmar 8 1982 and have noticed and oil leak? I say questionmark because the dealer in NJ said that an occl drip is ok.
every week or so I see one drop or so that starts from the back of the bilge and drips to the front of the bilge.

It has not affected the level of oil in the last 5 months but I am just a little concerned about it.
Is there a way to trouble it? could it be coming from the engine trans joint?Has anyone had a similar situation?
any ideas would be appreciated.



Mibrinn@aol.com
Scott Ritchey

Re: oil leak

Post by Scott Ritchey »

This is certainly not an emergency. So take your time and see if you can isolate it.

I'd recommend you start with a visual inspection. I assume the leaking oil is black. That would make it engine oil vs transmission oil. Get a small mirror and a good flashlight and see what you can see. Use the mirror both to bounce the flashlight beam and to see. This technique allows you to see in many places where your head won't fit.

The YSM-8 (and its cousins) have a rather simple oil system so look at the shop manual and identify possible sources. The two "hard" ones (hard to fix)are the pan and the crank shaft seal.
mibrinn wrote: I have a Yanmar 8 1982 and have noticed and oil leak? I say questionmark because the dealer in NJ said that an occl drip is ok.
every week or so I see one drop or so that starts from the back of the bilge and drips to the front of the bilge.

It has not affected the level of oil in the last 5 months but I am just a little concerned about it.
Is there a way to trouble it? could it be coming from the engine trans joint?Has anyone had a similar situation?
any ideas would be appreciated.


RitcheyVS@aol.com
Jeff.Schmoyer

Re: oil leak

Post by Jeff.Schmoyer »

mibrinn wrote: I have a Yanmar 8 1982 and have noticed and oil leak? I say questionmark because the dealer in NJ said that an occl drip is ok.
every week or so I see one drop or so that starts from the back of the bilge and drips to the front of the bilge.
I have the same engine and I have that same leak too...seems to originate from the starboard rear of engine. But it's NOT crankcase oil, which turns black within an hour of opperation after an oil change (this is normal). It's mostly clear, appears to be unburnt diesel oil! And it tends to appear after I run the engine at high revs.

I think it's just some kind of 'blow by', and I don't know whether it's bad or not.

Jeff




jeff.schmoyer@iff.com
Larry DeMers

Re: oil leak

Post by Larry DeMers »

If this is engine fuel, not crankcase oil (is it black or clear brown?), it is probably blow-by. On my Volvo MD7B, I do get blow-by at high RPM. This blow-by dribbles out the engine air intake horn, which faces downward. This is an effect of the valve timing and valve seating. Blow-by is caused by (amongst other things) an intake valve that did not shut quite as tightly as you would prefer, sending some of the fuel/air mixture to the air intake horn upon compression.

Larry DeMers
s/v DeLaMer
Cape Dory 30

mibrinn wrote: I have a Yanmar 8 1982 and have noticed and oil leak? I say questionmark because the dealer in NJ said that an occl drip is ok.
every week or so I see one drop or so that starts from the back of the bilge and drips to the front of the bilge.

It has not affected the level of oil in the last 5 months but I am just a little concerned about it.
Is there a way to trouble it? could it be coming from the engine trans joint?Has anyone had a similar situation?
any ideas would be appreciated.


demers@sgi.com
Richard Feffer

Re: oil leak

Post by Richard Feffer »

Check the fittings on the mechanical fuel pump (starboard side rear). Sometimes those copper gaskets seep a little fuel.

Richard
CD30MKII
Adamarie



RichFef@Prodigy.net
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