Yanmar SD25 - water in oil?

[wonkywinch]

Thank you Vic, I'm on the boat now, running in gear. Will take new sample after 30 mins and see what that looks like. I appreciate your guidance as it would be a waste of time sending oil that was only from the top/idling gears of the drive.

 

[Halo]

I suggest you keep a sample of the oil that Yanmar provided. If you get into a dispute it could be valuable.

 

[wonkywinch]

40 mins eng running 1500rpm with prop engaged, two hard bursts of power then sampled oil ..

 

[wonkywinch]

Water it was. Although the seals looked intact and no water in the bottom of the sail drive, they were replaced. Then after the boat went back in, the results of the oil test came back.

1460ppm water.

 

[westernman]

That is not a lot of water. 0.1%.

 

[vyv_cox]

That is not a lot of water. 0.1%.

Not much but it seems gearbox oils need only 200 - 600 ppm. I cannot see this as a serious leak though.

 

[wonkywinch]

Not much but it seems gearbox oils need only 200 - 600 ppm. I cannot see this as a serious leak though.

The Yanmar techs couldn't find any problems and said the old seals looked OK but the foaming oil issue wasn't right so the cost was an investment vs trashing the saildrive.

 

[timsharpe62]

Thanks for this information its very useful. Out of interest how much was it to replace the seals? I've got a similar issue, but not as marked (SD25 on a 3YM30, saildrive <3 years old and oil changed in May).

Its not been overflowing, I'm just noticing some bubbles on the surface when i check the oil (I do this as part of the engine checks with every use, interested that this might not be neccesary - but if I hadn't I would have seen this...). A couple of days later I took some oil out in a syringe and the bubbles were small and just on the surface and dissappeared quite quickly and the oil appeared clear after that.

However some context was that we were away on the west coast of scotland for 8 days, with light winds, so much more motoring than normal (maybe 4-6 hours a day), so had a lot of use.