Oil in the bilge

[Wakatere]

I found oil in the bilge sump this weekend. There doesn't seem to be any missing from the engine (Beta 14HP), which is running as normal.

A while ago I overdid the stern gland greaser and a little pile of grease oozed out - I know I should have cleared it up at the time but that's in the past now. Is it possible that this has melted in the recent almost-summer weather and turned from well, grease, to the black oily stuff I have now? If not, given that I can't identify another source what could it be?

Cleaning it up will have to go "on the list" fairly high up now of course - anybody found a list management app that makes the list shorter while you're watching TV?


TIA
Charles
Wakatere - Elizabethan 9m

 

[bedouin]

I know from recent experience that a little oil in the bilge goes a long way - you would not necessarily notice the drop in level on the dipstick.

The oil absorbant mats/cloths are very good - I would put one under the engine and see what happens (it is good practice anyway to mop up the odd spill).

 

[Davegriff]

Water with a very thin film of blackened oil on top, when in the depths and dark of the bilges, can often appear to be 'pure' oil. Simple to remove and clean up after with washing up liquid.

 

[Big-Bang1]

Could it be a split breather hose with the resulting oil vapour condensing and forming the oil in your bilge? As has already been said it doesn't take much to go a long way.

 

[lw395]

Black oil is almost always going to be sump oil.
Sorry!

 

[James_Calvert]

Water with a very thin film of blackened oil on top, when in the depths and dark of the bilges, can often appear to be 'pure' oil. Simple to remove and clean up after with washing up liquid.

A few years ago I was a bit lazy about pumping out some "water". When I got round to it, the fluid turned out to be gearbox oil...

 

[Wakatere]

Thanks all for the comments - I'll have a few things to check when I next get to the boat.

 

[scottie]

Check seawater pump telltales

 

[Davegriff]

A few years ago I was a bit lazy about pumping out some "water". When I got round to it, the fluid turned out to be gearbox oil...

But the OP says he cannot identify a source of any leaks, so good chance its only a thin skim of oil sat atop water. I had the same 'problem' for years until I got round to replacing the mounting gasket under my fuel lift pump. Really no noticeable oil loss (not even enough to more than stain a couple of square inches of tissue paper per 2-3 months), but until the bilge water was pumped out and examined, it always looked like black oil whilst in the bilges. New gasket sorted it.

 

[James_Calvert]

But the OP says he cannot identify a source of any leaks, so good chance its only a thin skim of oil sat atop water. I had the same 'problem' for years until I got round to replacing the mounting gasket under my fuel lift pump. Really no noticeable oil loss (not even enough to more than stain a couple of square inches of tissue paper per 2-3 months), but until the bilge water was pumped out and examined, it always looked like black oil whilst in the bilges. New gasket sorted it.

Not disagreeing with you. In my case, there weren't any active leaks to be seen because the gearbox had emptied down to the level of the oil seal that had become displaced.

 

[chrishelen]

Could it be spilt fuel?