I have a Yanmar 2 GM20. Finally got away from the dock this weekend. Upon returning and cooling down the engine I checked the oil. It appears to have increased in volume. Trying to figure out what it could be. It did not appear milky or watery. It did appear to be thin and grey. Could it be fuel? Where would it come from? Any suggestions as to where to start are appreciated.
More Oil???
- Thread starter Rich M
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Could be fuel. Not uncommon for fuel to get into the crankcase from a leaking diaphragm in the lift pump.. Unfortunately, you can't buy a rebuild kit so IF that is the problem, a new pump is in order . Yanmar part number is 121256-52021
Ya should be able to smell the diesel in the oil if that much is getting in.
Ya should be able to smell the diesel in the oil if that much is getting in.
Kloudie
I have a leak coming under the rear engine and noticing leak also coming from all over the back of tranny and a pan under engine is collecting what seems to be all oil but I never need to add oil and so I am thinking fuel is leaking into oil and that is why it shows full oil on dipstick.
is the lift pump what they call fuel feed pump in the yanmar manual.
I have the yanmar manual for my 3YM30 engine and been checking it out and when I pull the boat for bottom paint some time after I return from vacation up north for the summer months I will attempt to repair this fuel feed pump and also the rear engine seal too.
I have never really done much repairs on these Yanmar except just rebuilt the sea water pump for my engine but have always repair cars and trucks and I did have a GMC diesel truck that always needed repairing.
Nick
I have a leak coming under the rear engine and noticing leak also coming from all over the back of tranny and a pan under engine is collecting what seems to be all oil but I never need to add oil and so I am thinking fuel is leaking into oil and that is why it shows full oil on dipstick.
is the lift pump what they call fuel feed pump in the yanmar manual.
I have the yanmar manual for my 3YM30 engine and been checking it out and when I pull the boat for bottom paint some time after I return from vacation up north for the summer months I will attempt to repair this fuel feed pump and also the rear engine seal too.
I have never really done much repairs on these Yanmar except just rebuilt the sea water pump for my engine but have always repair cars and trucks and I did have a GMC diesel truck that always needed repairing.
Nick
Nick.. yup, fuel feed is same as lift pump, the little mechanically driven pump on the side of the block.
strange symptoms.. but ya may be correct .. also check very carefully, the banjo connectors, and hose especially the one on the discharge side of the feed pump. Good Luck !
strange symptoms.. but ya may be correct .. also check very carefully, the banjo connectors, and hose especially the one on the discharge side of the feed pump. Good Luck !
Kloudie,
Thanks for the input. Finally had the opportunity to replace the fuel pump today (after changing the oil) and everything appears to be back to normal. Or as normal as a as 28 year old boat & engine can be. Hope to actually get out next weekend and enjoy some of the Chesapeake Bay. Thanks again.
Thanks for the input. Finally had the opportunity to replace the fuel pump today (after changing the oil) and everything appears to be back to normal. Or as normal as a as 28 year old boat & engine can be. Hope to actually get out next weekend and enjoy some of the Chesapeake Bay. Thanks again.
You are welcome, Rich..
I had a 28 year old piece of fuel hose fail yesterday.. The hose that returns fuel from the injectors to the tank.. I (wrongly) figured.. hey there is no pressure in there so it will be OK.. A crack in the old hose finally made its way through and I got about a quart of diesel under the tank and into the bilge.. what a stinky mess! Make sure all the fuel hoses are kinda new so you don't get the stinky job of trying to clean that up !
Good Luck. Happy sailing
I had a 28 year old piece of fuel hose fail yesterday.. The hose that returns fuel from the injectors to the tank.. I (wrongly) figured.. hey there is no pressure in there so it will be OK.. A crack in the old hose finally made its way through and I got about a quart of diesel under the tank and into the bilge.. what a stinky mess! Make sure all the fuel hoses are kinda new so you don't get the stinky job of trying to clean that up !
Good Luck. Happy sailing
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