2006 mercury 90hp efi water in oil?

[seapro176]

Ichanged the oil in my 2006 mercury efi 4stroke and it was full of water.I dont know how long the water has been in there, but still runs perfect. i changed the gasket under the power head thinking maybe it was getting in through there and the oil pan gasket while i had it apart. put it back together and water in the oil again.... compression check almost identical on all cylinders at around 135psi, so thinking head gasket probably not the problem. Any ideas where the water might be coming from before i throw more parts at it.

 

[seapro176]

Re: 2006 mercury 90hp efi water in oil?

I'm stumped, and any help would be a life saver

 

[Texasmark]

Re: 2006 mercury 90hp efi water in oil?

I am not a 4 stroke guy but I recall mention of condensation being a problem in the crankcases of 4 strokes. Apparently the problems arise from lack of adequate usage to drive the moisture out of the oil.

How does it get in there? I forget all the technical (been retired for a number of years), but if you have a container open to the atmosphere, even a little, it will breathe. Problem is that it breathes in air containing moisture, but retains the moisture. To rid yourself of it you have to heat the chamber to force the water to "boil" for lack of another word and be expelled however it can get out.

I used to fight the problem on aircraft systems. If you didn't have an open container that could drain on it's own it had to be Hermetically sealed to prevent the inclusion of water.....think of a glass of iced tea sitting on the patio table in the summer. As long as the atmosphere contains water and the container is cooler, the water will condense and remain inside (as the container adjusts to atmospheric changes....breathes) if it can't get out.

So, my suggestion is change your oil and get your rig out and run it. Summer coming on helps too. If, after a reasonable length of time you still have water, then it might indicate a mechanical problem needing a solution.

My 2c,
Mark

 

[seapro176]

Re: 2006 mercury 90hp efi water in oil?

Before changing the base gasket under the power head there was a lot of water. Way more than could be moisture. I have owned it since new and changed the oil yearly even if the hours don't warrant yet. And never seen this much water. So I changed base gasket and exhaust plate gasket, cleaned out oil pan and poured about two quarts through power head before putting it back together. Then refilled and ran in the driveway for about 15 or 20 minutes and checked oil and milky colored again...

 

[Texasmark]

Re: 2006 mercury 90hp efi water in oil?

Looks like you have a water leak.

Good luck,
Mark

 

[seapro176]

Re: 2006 mercury 90hp efi water in oil?

Yep just can't figure out where. I was hoping someone may have had a similar situation, and might steer me in the right direction. Thanks for your help Mark!

 

[1nebel0]

Re: 2006 mercury 90hp efi water in oil?

This is a common problem on all 4 strokes.. called making water and they make a lot of water...Texasmark nailed it.....you cannot idle these motors not troll with them...go figure...most of the time it is a bad therm and very rarely a base gasket or head gasket...you need to do a leak down test to make sure it isn't a head gasket...99% of the time it is due to the engine running too cold with cold water splashing up against the oil pump...You can idle that motor on the hose for an hour and the oil doesn't even get warm...Google it and read all about the problem... I have a 115 on a pontoon boat and glad my other boats are all good old 2 strokes..the only good thing about the 4 stroke is the fuel economy as I go broke running my 245h.p. Bridgeport motor on my Daytona at 14 gallons every half hour..Ouch!