Oil shoots out of dip-stick hole?

[ejessen]

I have a 1987 hunter 31, with a pretty well maintained Yanmar (2GM20F) engine.

Today, we noticed a lot of smoke coming from the engine compartment, and quickly went back to the slip.

Underneath the engine, there was about a half an inch of oil, and it turned out that the dip-stick had worked itself out and oil had been shooting out of the dip-stick hole.

Anyone else had this happen. Is this just something for me to check before each time we go out, or is there another, bigger, underlying issue?

-- Erik

 

[Sailm8]

I have had this happen on my 1gm. It was operator error. The dipstick was not properly reseated when I checked the oil. My dipstick has 2 rubber detents and it needed to be replaced with a double "click". Now I am careful (on my 2gm) to feel the double "click" and feel with my finger to make sure it is seated.

 

[seadaddler]

Same

I had same thing happen once and did not put dip stick in
or some thing and what a mess after running engine and did not know until
after mess.
Nick

 

[Rich Stidger]

I think that this condition is due to excessive crankcase pressure. Check the breather vent for a blockage first. If that is clear, then my next guess would be blow-by due to worn rings or a head gasket leak to an oil galley or a gasket leak between the exhaust manifold and an oil galley.

The only high pressure in the engine is the after-combustion exhaust and that pressure is somehow getting to the crankcase to push out the dipstick and oil to follow.

A compression test would test for worn rings or a leaking cylinder through the head gasket. A gasket leak on the exhaust manifold is harder to test.

Good luck. Let us know what you find.

Edited: After reading the above replies, I was not aware that on your engine a loose dip-stick can cause a leak. I have never seen that situation. I hope that is your simple answer.

 

[kloudie1]

Dipstick seating is a good one to check, the crankcase breather and breather hose in the back end of the valve cover is another.. the expensive cause would be severely worn piston rings, but if you are not seeing blue smoke and the engine starts easily, it is probably one of the first two.. oh.. make sure that someone has not overfilled the oil. and check to see that diesel or water is not getting into the oil and raising the level..

 

[Nereussailor]

Follow Rich's post and check the breather. There is a small hole inside the head under the breather. Make sure it's not plugged. I had the same problem and it was the dipstick not seating properly. As the dipstick gets older the rubber gets hard and shrinks a little bit. Yanmar wants $37 for a new dipstick. Long answer short, clean the dipstick rubber really good, put a snug piece of electrical shrink tube on it and carefully heat it to shrink it tight. it will make the dipstick tight in the hole. Cost....... 50 cents.

 

[Jerry Clark H356 SV Persi]

Forgot to seat my dipstick on 3GM30f, had oil all over the place. You won't forget to stick it in tight again.