Oil Leak in Nanni Kubota 2.45 Eco

[Asmodeane]

Hi guys.

I've recently bought an Albin Vega with a Nanni Kubota 2.45 Eco 10hp diesel installed in 2002, with about 200 running hours on it. The packing gland was also changed, as well as the transmission. I've ran it for around 12 hours so far, and have been really happy with the low consumption and silent as well as reliable operation.

But.

Last time I came on board and checked the engine before heading out of the harbor, there was a small amount of oil in the sump under the engine. Not much, maybe half a shot glass (about 20ml). And it didn't leak during the last time I used the engine, but some time during the 5 days that the boat sat idle at the dock. Also, after using the engine for about three hours that evening the amount of oil didn't increase.

Is this sort of behavior normal? I don't know where the oil is coming from, couldn't see any obvious trails. Could it be the packing gland? It has some sort of an oil system itself, with a separate little oil tank.

The engine sensors didn't complain that oil was low or that it was overheating or anything either.

I guess what I am asking is, should I be worried and try to locate and fix the problem "at any cost" or just monitor for signs of it getting worse?

[Chief Engineer]

If you don't know where it is coming from...monitor it.

Put a couple oilsorbs under the engine.

Don't use disposable diapers...as they degrade into a gloppy mess when subjected to water for any length of time

[Celestialsailor]

Check the pan bolts and other fasteners.

[Hydra]

Asmodeane,
I have a Nanni 2.50 HE diesel from 1995, probably similar to your 2.45. On my engine, there is an oil overflow pipe going back to the air intake manifold, to burn the excess oil. If this pipe happens to become disconnected, some oil will flow and finally arrive in the sump.

So, I suggest that you check all pipes on the engine and the oil level on the dipstick: it should not exceed the high mark on the stick, for this excess oil will be burned in the engine, possibly causing overspeeding.

Also check the odor of the oil you found: the engine oil smells differently from the gearbox oil.

Alain

[Asmodeane]

Thank you all for your answers!

I just came back from the boat, and no more oil has leaked during the past few days that she lay at her moorings. Weird. I guess it might have been a one-off sort of thing. Perhaps it was indeed the excess oil, will have to check out the manual and see where it comes out. There is a little rubber hose hanging over the sump, coming out of the engine, and it is suspiciously oily, so maybe that's the culprit? At any rate, it is engine oil, judging by the smell. Will be lifting the boat out for the winter soon, and will check the engine thoroughly during the winterizing process.