yanmar SD 50 saildrive oil looks odd

[markdbrewer]

Checked oil as usual in SD 50, and it looked normal, although slightly overfull.
Motored over to yard for a brief haul-out, and motored back next day. Went to remove some of the excess oil, and found that oil was down some on the little dipstick, and it looks thicker and kind of green. Not really milky, which I think means water intrusion, but maybe close.
Prior to to this, the oil has probably been in this saildrive at least 25 hours of run time. No other symptoms in shifting gears etc.
Any thoughts or advice would be appreciated.
Mark

[Diesel Bill]

I would renew the oil and monitor it closely for a while. If really worried get it analysed.

[boatbod]

Usually the culprit is the o-ring on the oil drain screw.

[Thumbs Up]

I don't know how the level could go down if water was getting in but overfilling an unvented saildrive can cause it to suck water past the seals when it cools off. Also if you know that the seal is leaking you can loosen the cap after you shut it off and it won't leak. Don't forget to retighten it though.

[Aqualibrium]

on 16th September 2009 Yanmar issued a service Bulletin GTB2009016 which lowered the oil level in an SD50 saildrive by 14.5mm.
This was due to limited airspace and pressure build up due to temperature forcing oil out past the seal!

I bought my engines after this date but of course they had the shorter dipsticks and no one at Power Equipment advised me.

I have had factory assembly problems with both my 3JH4Es and have a very low opinion of Yanmar and their Distributor in Australia.

Of course the longer dipsticks are available at a price but the difference between the high and low oil marks on the shorter dipstick is 15mm so use the lower mark as your high level and you will be complying with their reccommendations

[boxxy]

Originally Posted by Aqualibrium

on 16th September 2009 Yanmar issued a service Bulletin GTB2009016 which lowered the oil level in an SD50 saildrive by 14.5mm.
This was due to limited airspace and pressure build up due to temperature forcing oil out past the seal!

I bought my engines after this date but of course they had the shorter dipsticks and no one at Power Equipment advised me.

I have had factory assembly problems with both my 3JH4Es and have a very low opinion of Yanmar and their Distributor in Australia.

Of course the longer dipsticks are available at a price but the difference between the high and low oil marks on the shorter dipstick is 15mm so use the lower mark as your high level and you will be complying with their reccommendations

Thanks Aqualibrium for the info - I've just bought a boat with a 2009 SD50, and am unsure if I have the old, short dipstick, or the correct, long dipstick - could you by chance let me know the total length of the new/longer dipstick so I can check which one I have? Much appreciated!

[GordMay]

Greetings and welcome aboard the CF, boxxy.