Water In Engine Oil

2006 Mercury 25 HP Stroke EFI. Starts and runs great. Checked oil today and level was way HIGH. Not a creamy color. Does not smell like gas. Looks like water. Going to drain and replace oil and filter this week. Is this normal. I run the 16' boat in the inner coastal waters of Florida. Some days water is quite rough and I bounce along for 3 to 5 miles. Motor never misses a beat.
Thoughts appreciated.
IRS

You can set a hot plate or electric frypan to 230-250 and drop some oil on. If there is water in it, it will bubble up immediately. If not drag a lit match through it. If it fires up, it’s fuel. That will let you know where to start looking.


Sent from my iPhone using Tapatalk

I have a 2013 30hp four stroke, and I have found it to be a little touchy about over filling at oil changes. Be sure that you get all of the old oil out. The manual says to have the engine tilted and turned to starboard to drain, but if you have it too high, it does't completely drain. Not sure if there is a difference in capacities between the years, but mine says 1.8qts, don't over fill it. If it does't "crackle" when you put heat to a drop or two oil, there is no water. Think about what happens when you spill water into a hot frying pan.

Good luck and let us know what you find,

John

I had a later version of the same outboard. I recall the owners manual discussing impact of excessive trolling at idle. I did a lot of trolling and my oil level always seemed to be high. Don't know if the two are related and unfortunately I no longer have the outboard or the manual and cannot remember the details.

Changed oil and filter. Measured drained oil (including filter) and got 2.0 quarts. Mercury says engine takes 1.9 quarts. Dropped a bit of drained oil on hot pan - no sizzling or bubbles. Tried to ignite oil with lighter - no ignition. I must have been seeing things when, before the oil change, my dip stick showed a quite high level. Will monitor and hope for best. Thanks for feedback.

It "could" be normal.

One of the "downsides" of 4 stroke outboards is that they'll sometimes "make oil"--so to speak. In other words, the oil level can rise. This is most common on motors that are used in cold climates and cold water and/or do a lot of idling/low speed running. If this describes your type usage, it is considered mostly normal.

So what happens is that a small amount of fuel and air get past the piston rings and into the crankcase. Over time it builds up, UNLESS the engine is run enough, and hard enough, to get the engine oil above about 150 degrees F, at which time the contaminants will boil off.

How to prevent. Change oil more frequently if you do a lot of idling and/or run often in cold temps. Or just make a few laps around the lake at half throttle or more which'll boil off any unburned hydrocarbons and any moisture.

Also-if a thermostat sticks "open", they'll do the same thing. And-it's hard on the engine. The thermostat needs to work and work properly especially on an EFI engine that is dependent on engine temp to calculate the fuel injection.

Not to say there ain't a problem...but a little is normal, happens over time. But if it's excessive and happens in a short amount of time, you may have another issue-such as a leaky fuel pump, or whatever.

Another factor affecting oil level is the oil temperature when doing the check.

On my Yamaha jet ski engine, they specifically call out only to check it hot. The difference between cold & hot is about 15%.

Glad to hear you don't have a cracked engine.

The advice about boiling the oil looks really good, but I personally have never tried it. Well, I came to this thread just to ask one question - what was the source of the problem? I am new to boating and I recently encountered a similar problem that shocked me. I don't know anyone who is into boats so I had no better option than to find a thread with a similar problem and ask a question there. I would really love it if any of you could answer this question, thanks in advance! I've never had a similar problem in a car, so I don't have anything to compare it to. I may have been using poor quality oil in the boat engine, which could also have caused the problem. Next time I will try to find a better quality oil, hopefully there is an analogue of cararac.com but for boats