Oil in lower unit reservoir

toolmaker312

My port engine recently clunked going into gear. Opened up the engine hatch and noticed oil in the bilge. The lower unit Reservoir also looks milky. At the beginning of the year it seemed like I had to fill it a couple extra times. I'm wondering if I left the drain plugs or vent plugs loose on the lower unit

PickleRick

Since you need to remove and clean the reservoir anyway,  if you can get your hands on a sub 30 dollar carburetor vacuum/pressure tester you can likely find you leak in the water 

Remove the reservoir and attach the barbed hose from the pressure tester to your oil feed hose. You only need to push it up to 5psi.
So long as the leak is below the water line you should see where the bubbles are coming from. 


It should hold press for 24 hours without leaking down.

toolmaker312

Thanks for the idea! Any idea why there might be oil in the bilge? It looks like it's darker kind of like the bluish tint of the lower unit oil. 

toolmaker312

I may have had another not so brilliant idea. I started storing my outdrives all the way up thinking there will be less growth on the shafts and would help the seals for the hydraulic cylinders. I am wondering if that's why some of the oil might be getting back in the bilge

PickleRick

I doubt that's why you have oil in the bilge but for gimball bellow life id keep it stored in the down position.

Follow your oil reservoir to as close to the transom as you can.  Since oil flows down hill follow the hose until it starts getting oily.

Could the the reservoir, the hose or the pita plastic connector at the transom housing. Could just be loose clamps on the hose 

I'm assuming you mean outdrive oil in the bilge.

I have a Bayliner with a diesel so there's all sorts of oils mixed in my bilge.

toolmaker312

Thanks. This is the first time I've had oil in the bilge. I kind of saw all of this on my way out. I was hoping to use a few of these ideas next time I go down

YYZRC

Are you sure it’s gear oil (blue) in the bilge? The remote oil filter lines are prone to leaks. 

PickleRick

Like @YYZRC said the oils have different colors.  Red for power steering.  Brownish for motor oil.  Red for power steering.  Blue for drive. 

toolmaker312

I am pretty sure it was the dark green for the lower unit. After hearing a little clunk shifting into gears and seeing the Milky color at the bottom of the reservoir I jump to the conclusion it was the lower unit oil, but not 100% sure. After sleeping on it I think it is a seal that is filling up the bellows that when I bring the motors back down it pushes it it into the bilge. Is this a possibility and what seal would it be?

YYZRC

Could be a cracked fitting assembly in the transom assembly:

https://www.marineengine.com/newparts/part_details.php?pnum=MER22-861150T02

toolmaker312

I will be going back next weekend to try to do a pressure test

PickleRick

That fitting that @YYZRC just posted is plastic and usually brittle due to age.  When replacing my leaky reservoir and old probably original hose the fitting snapped.   I now keep an extra one on hand so if it happens again I won't lose a weekend on the water.   

YYZRC

Maybe take some photos? Could be helpful to diagnose.

toolmaker312

The reservoir used to be clean I don't know if the previous owner cleaned it out or this is somewhat normal with with a a small amount of residue. There is oil in the bilge though also