Lower unit oil…again

[Peach1303]

2008 Mercury 225 Pro XS. 1B506554.

Alright, the frustration with this boat has mounted. Now, it has run great for me but it seems like there is always something going on with it. Had some issues this year that I ended up getting cleared up, and its worked well. I bought it used, a year ago. It had water in the lower unit when I bought it…had the LU pressure tested and it checked out just fine, so I assumed it was the washers/gaskets for the drain screws. Later on in the year, I had the water pump replaced, no big deal. I started to winterize it today (yes, I'm behind the 8 ball for Chicago), and yet again there is water in the LU. I have not had any leaks of oil coming from the LU, but somewhere somehow there is water intrusion. FYI, it is extremely difficult to find a reliable and affordable mechanic/technician in the area, so Im kind of at the point of becoming a DIYer. Has anyone had this happen to them two years in a row after being told that it pressure tested just fine? What are my other possibilities? Shift shaft seal? Also, there are extremely, extremely, fine particles…you can only see them if the light hits it a certain way. I would assume that is normal from what I have read. Basically looking for a place to start ironing this issue out.

[Peach1303]

Update:

The casing where the washers/seals for the screws is blueish in color, and the screws have a blue color on their backside. I don't know if that is from old blue washers, but I have replaced the oil, put a washer (yellow) on each screw, and put reinstalled the screws. The bottom drain plug actually had a blue washer on it, which appeared to be a different size than the yellow washers and Im starting to think that that may have been the problem. Im guessing when they replaced the water pump/pressure test they may have used the wrong washer. Sad part is now I have to wait for open water to try it out and see if that is the issue or not.

[Savage]

Re-sealing a lower unit requires special tools. Send your lower unit out to have it re-sealed.

[X19Indy]

If that doesn't fix it take it to Sherms in Wabash Indiana. He will fix you up in a reasonable time and money. It is about a 2 hour drive for you but worth it in my opinion for good service.

[06 SB]

If that doesn't fix it take it to Sherms in Wabash Indiana. He will fix you up in a reasonable time and money. It is about a 2 hour drive for you but worth it in my opinion for good service.

GOOD ADVICE right there. I drive 3 hours to Don.

[EuropeanAM]

+2 on Sherm.

[long shot]

Maybe the shop was using the bottom port to apply the vacuum and pressure and therefore sealed the leak while testing for it? Then reinstalled the leaking drain plug?