Mercruiser 5.7 EFI Water in Oil

[sarnone]

When you install the gaskets keep in mind that proper torque is very important. I would use a thread chaser to clean the threads for the bolts that thread into the manifolds, and clean the threads on the bolts itself. Follow the manufacturer’s instructions about how to install the gaskets and use a torque wrench. Some need to be retightened after the initial warm up.
The ultimate solution (but very expensive) might be converting the wet exhaust you have to dry joint if you need to replace these. However properly installed you should be able to get then to seal with no leaks.

Lou c, thanks. I found a torque spec of 33ftlbs, but I am a little weary of that. The bolt head 9/16. Not sure if the diameter of the bolt, I think 3/8.

Sarnone

 

[Lou C]

The main thing is that your threads & bolts are clean enough that they thread all the way in easily. If rusty you will encounter resistance & the torque wrench will read the 33 ft lbs but the actual clamping force on the gasket won’t be adequate to prevent leaks.
When I replaced the cyl heads on my 4.3 I spent literally a few hours cleaning out the 26 cyl bolt holes on the old short block. The original bolts were so rusty I just replaced them with new ARP bolts.

 

[Scott06]

Scott06, thank you. However, cooling system was fully drained before I took it apart. Also, there is a drain point directly below this location.

Yes I know that but when I have done the same it seems like some water sits on top of gaskets.

As others have stated make sure surfaces are flat, use the OEM metal/fiber (not paper) gaskets, and a little perfect seal/permatex #3 on the bolt threads so they come out down the road.

 

[Scott06]

Lou c, thanks. I found a torque spec of 33ftlbs, but I am a little weary of that. The bolt head 9/16. Not sure if the diameter of the bolt, I think 3/8.

Sarnone

Yes they are 3/8-16 threads. 33 ft pounds is correct

 

[sarnone]

Many thanks to everybody you have their input. I bought gaskets and permatex nonhardening. I cleaned up and made sure the joints were flat. I reassembled everything, fired up the engine and after some time checked and the milkshake was gone. Gonna change the oil and re-winterize.

Thanks
Sarnone

 

[Scott06]

Many thanks to everybody you have their input. I bought gaskets and permatex nonhardening. I cleaned up and made sure the joints were flat. I reassembled everything, fired up the engine and after some time checked and the milkshake was gone. Gonna change the oil and re-winterize.

Thanks
Sarnone

Great you may have to do another oil change in spring to get all the milk out.

 

[Lou C]

Or put it in the water & run it till it’s good & warm. Up on plane for a while…

 

[sarnone]

Or put it in the water & run it till it’s good & warm. Up on plane for a while…

Ya, that’s my question, the oils is brand new from winterizing. I can change it again. But if it would evaporate out then I really don’t need to do I?

Sarnone

 

[Lou C]

I think it’s better to run it once to burn the moisture out of the oil. Don’t think you need to change it again after that

 

[Lou C]

Also, water in the oil does not always show up running at idle with no load, running it on plane so there is a load on the engine, is the true test. This way you know for sure that this was the cause and it's fixed rather than finding out start of next season.

 

[alldodge]

Agree, it being easy enough to run and check I would run it. As said this will burn off the remaining water and no need to change afterwards

 

[sarnone]

Also, water in the oil does not always show up running at idle with no load, running it on plane so there is a load on the engine, is the true test. This way you know for sure that this was the cause and it's fixed rather than finding out start of next season.

Lou C, thanks. You are absolutely right about that. Running the boat on plane is what revealed the problem in the first place. I will put the drain plug back in and take it for a spin. Hopefully then I can winterize with confidence.
Question, I normally fill my fuel filters with 2oz of 2cycle oil and turn off the fuel, to winterize the combustion chambers. I now have two brand new fuel filters I have to trash(or one) in order to do it again. Do have an alternative method for this part of the winterization?

Steve

 

[sarnone]

I need to elaborate on my winterizing of the cyclinders…2oz of oil in the center of the fuel filter, which is post filter, shut off fuel, run until it dies…this is in the merc manual for the lay up procedure.
Thanks

 

[Lou C]

That I can’t say, I have only had the old fashioned boat with the carb & mechanical fuel pump. However I do know a few people who don’t bother with that procedure on EFI boats. At this point I would be more concerned that the water in the oil problem is truly fixed. Because if not you have some work ahead of you & the time to do it is now vs finding out at the start of next season. I went thru this when I replaced the heads on my old 4.3, was done early fall but didn’t want to put it in again so waited till spring and had a lot of anxiety about the first few runs. Turns out it was fine verified by several oil analyses done via Blackstone Labs.

 

[Scott06]

Lou C, thanks. You are absolutely right about that. Running the boat on plane is what revealed the problem in the first place. I will put the drain plug back in and take it for a spin. Hopefully then I can winterize with confidence.
Question, I normally fill my fuel filters with 2oz of 2cycle oil and turn off the fuel, to winterize the combustion chambers. I now have two brand new fuel filters I have to trash(or one) in order to do it again. Do have an alternative method for this part of the winterization?

Steve

Why do you have to trash the filter? Let the fuel clean it out and run through it in the spring

 

[sarnone]

Why do you have to trash the filter? Let the fuel clean it out and run through it in the spring

After I run the 2 cycle oil through the filter, i assume i have just ruined its ability to filter the fuel properly. Maybe, I am wrong...

 

[sarnone]

That I can’t say, I have only had the old fashioned boat with the carb & mechanical fuel pump. However I do know a few people who don’t bother with that procedure on EFI boats. At this point I would be more concerned that the water in the oil problem is truly fixed. Because if not you have some work ahead of you & the time to do it is now vs finding out at the start of next season. I went thru this when I replaced the heads on my old 4.3, was done early fall but didn’t want to put it in again so waited till spring and had a lot of anxiety about the first few runs. Turns out it was fine verified by several oil analyses done via Blackstone Labs.

Lou C, I just finished my test run. I checked the oil at the dock and no issues.
I do have some minor temperature fluctuations that I would like to ask about in another thread. They are unrelated to changes made due to the milky oil.
Thanks for your help.
steve

 

[Lou C]

I think once the 2 cycle fuel is used up the filter is still good because you leave it on the whole next session right?
Glad you don’t see any water in the oil!

 

[sarnone]

I think once the 2 cycle fuel is used up the filter is still good because you leave it on the whole next session right?
Glad you don’t see any water in the oil!

I put oil in the fuel filter that was used during the season. Once the engine dies from the 2cycle, I remove the old and put the new one on, making ready for the next season.

 

[Lou C]

I put oil in the fuel filter that was used during the season. Once the engine dies from the 2cycle, I remove the old and put the new one on, making ready for the next season.

Ah, I see what you were getting at then. I have the old carb engine so I just fog it thru the carb, and I change the fuel filter in spring.