2003 Merc 60 4-stroke Oil Leak

[kbudrow]

I bought this last spring from a dealer and it leaked instantly. At first I thought it was lower unit oil because thats where it seemed to be coming from, but it is actually engine oil leaking from the point where the lower unit connects to the main shaft. I brought it back to the dealer and they couldn't find anything wrong. The compression test turned out fine and they refuse to work with me on this now. I plan to take it to another dealer but I'm hoping someone can give me some insight as to what is wrong. There is a small oil slick on the water almost constantly but it hasn't leaked enough to change the oil level at all.

Thanks!

 

[Don S]

Re: 2003 Merc 60 4-stroke Oil Leak

There is a small oil slick on the water almost constantly but it hasn't leaked enough to change the oil level at all.

Is that an oil slick (layer of oil) or a rainbow effect? A rainbow could be from excess fuel?

 

[kbudrow]

Re: 2003 Merc 60 4-stroke Oil Leak

It's probably more of a rainbow. There is not much there. What do you mean excess fuel? I'm sorry, I really know very little about motors. I just like fishing

 

[kbudrow]

Re: 2003 Merc 60 4-stroke Oil Leak

There can also be a bead of oil built up after about a day on the plate on the lower unit when the motor is tilted up a little.

 

[bassman284]

Re: 2003 Merc 60 4-stroke Oil Leak

I have a 2001 Merc 40 4 stroke and I've had an oily film on that plate for about 10 years. I wipe it off from time to time but it always returns. Never any standing oil, just the film. It sends out a little rainbow when I drop it in the water. There is no sign of a leak and the oil level never goes down. A little annoying but I decided to quit worrying about it.

I got the idea somewhere that a little oil might have gotten spilled while changing the filter and keeps working its way down the leg. Keep it wiped down and you should pretty much eliminate the rainbow.

 

[Fleetwin]

Re: 2003 Merc 60 4-stroke Oil Leak

I have a newer Merc. 60 Four Stroke.

Once the oil is changed, a VERY messy process by the way, I seem to get a little oil dripping and collecting on the cavitatation plate-forever. If any oil is spilled in the lower cowling, during filter removal, it is just about impossible to get it all out.

If you are not using oil and the lower unit level remains full, I wouldn't worry about it. I would bet it's from the last service.

 

[woody66912]

Re: 2003 Merc 60 4-stroke Oil Leak

There were two issues with these, one was the o-ring on the oil pump under the cylinder head would leak. The other was a big issue. the oil pan was not lining up with the power head, I don't think it's the pan as you would be getting water in the oil. One thing I would do is to remove the side chaps and use a degrease on every thing, then run it in a garbage can and see where it leaks. There is also a plug on the port side that can only be seen when the side chaps are removed it is just below where the powerhead meets the exhaust plate. Or it could just be a valve cover o-ring leaking. Open the link the plug is # 10.



Boatinfo - Mercury Service Manual for 50-60 hp