Help! Yanmar 3YM30 dumped what seems like all of its oil!

[bernk]

I’m in the middle of my first bareboat charter. I’m skippering for my partner and her parents. Just did a routine evening engine check and to my horror there is a couple centimetres of oil sitting in the pan under the engine that was not there when I last checked. We’ve only motored a few hours (~3-4 max) since the start of charter. There was no overheat symptoms or alarms.
I found what looks like some sort of plug rolling around in the oil under the engine. No idea what it is or where it’s supposed to be, but I’m 100% sure it’s not supposed to be loose and swimming around in oil.
I’ll be calling the charter company first thing in the morning, but suggestions and ideas are more than welcome!

Thanks all!

[Neil C]

Looks like a blanking plug for the dip stick tube - weird arrangement.
With the dip stick missing the engine will spew some oil.

[sailormed]

If I recall correctly it is installed by Yanmar factory somewhere in the bottom part of the engine where an optional instrument sensor can be installed.
Look if you can find the hole, insert, secure and top up oil.

This is the proof that that is a lousy solution.

[Hanksy]

Looks a lot like the dipstick. Can you find where the dipstick should be? Starboard side about halfway along the engine. You should see the dispstick tube. Comes out near the bottom of the engine and extends nearly to the top about 30cm long.
I'd guess there will be a trail of oil wherever the leak came from too. Take a couple of pictures of the front and both sides of the engine.
Oil filter is on starboard side too so I'd be looking there for a leak.

[skipperpete]

Here ya go Bernk
The big question is how it came out! It takes a lot of crankcase pressure to blow that plug out.

[sailormed]

Take a round piece of wood (cloth hanger, kitchen spoon) cut to a tapered fit in the hole and hammer it for a tight fit.

[bernk]

It looks like whatever skipperpete highlighted is it. I’ll confirm in an hour or two when I start digging around. It’s 6:30 am here.

Any idea what that plug is called and what could have forced it out?

Thank you all for the help!

[bernk]

Looks like this in an alternate dip stick port and plug. I’ve found a thread in a ybw.com forum describing the exact same scenario.

[Poeme]

Some years ago and moments before leaving on a long trip, I did my routine engine check and found a large puddle of oil in the pan there...thought I had a catastrophe on my hands. But some time prior, I had simply not inserted the rubber plug on the dipstick fully home into the tube, letting a pint or more burp out. Cleaned the mess, checked the oil level, got underway...and haven't made that mistake since...

[canyonbat]

I think your best option is to make a pot of coffee and wait for the charter company to show up. No sense in doing anything that could shift the blame to you.

[Compass790]

Oh well the good news is the oil pressure alarm didnt go off ( assuming it's functioning ) so the engine should be ok.
Hell didnt think charterers did any engine checks?


The charter company should give ya a free day for discovering it before toasting the donk!
Hope the rest of the charter goes well & the crew aren't unduly concerned.

[skipperpete]

Originally Posted by bernk

Looks like this in an alternate dip stick port and plug. I’ve found a thread in a ybw.com forum describing the exact same scenario.

Your’e right Bernk, Kohler generators use this engine in some models also it’s a widely used industrial engine and the dip stick is in this position in these side access installations. The crankcase ventilation valve on the rocker cover could be the culprit and the engine might have excessive crankcase pressure......and you need a LOT of pressure to blow out a plug with such a frontal area.
Pete.

[TravelinLight]

High internal oil pressure could cause it to pop out. I would let the charter company sort it out so you do not have any liability.

[robgsailor]

Is itpossinly the saildrive dipstick?
I once had a friend reinsert the dipstick without screwing it in .
When I checked the bilge I noticed the oil and replenished the saildrive with .5l of oil.
That could explain why no engine alarms went off.

[Carlos M]

Originally Posted by skipperpete

Your’e right Bernk, Kohler generators use this engine in some models also it’s a widely used industrial engine and the dip stick is in this position in these side access installations. The crankcase ventilation valve on the rocker cover could be the culprit and the engine might have excessive crankcase pressure......and you need a LOT of pressure to blow out a plug with such a frontal area.
Pete.

Too much oil can also cause excessive crankcase pressure. How much oil can you read on the dipstick and how much you figure is in the pan bellow the engine? Have you checked oil level before using the engine?