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Water in oil

C

CAPTAIN America

New member
I have a 2013 mercruiser 383 stroker and have changed the exhaust manifold and exhaust risers. Started engine with fresh water to check for leaks. All good from the outside launched the boat and ran about 40 minutes and found oil level 2 quarts over full. Antifreeze at normal level. Plumbing is correct. Oil cooler was clean. Used a block off gasket and permatex high heat gasket sealant torqued risers t 25 ft/lbs manifolds torqued to 33 ftlbs. Salt water in oil.
Any experience much appreciated?
 
That is described as fresh water cooling, with the heat exchanger, holding the antifreeze...
Based on your description, it is the raw water entering the crankcase...assuming the exhaust work was done OK, that doesn't leave much...

The crankcase being overfilled is a new issue??
 
Well I found the problem. The block off gasket on the stbd side failed on the top where raw water enters the riser.
Seems like the permeates high heat optimum silicone gasket maker reacts with the rubber on the gasket.
It only failed on the raw water side not on the bottom (antifreeze side). And the port side is fine. Water in all four cylinders on stbd side, none on port side. It was recommended to o use aviation gasket sealer when I re-install. Going to replace both side, scared the other side will fai as well.
Thanks for listening and hope this might help someone avoid the same issue!
 
probably too much permatex silicone...

Perfect seal (Permatex #3 equivalent) is what the Merc manual suggests, and nothing else....sometimes the manual is a grand tool...

Hopefully you have the new gaskets and get the oil and filter changed soon...
 
It seems the gaskets were ok. Water was coming from the a hole in the riser water jacket. Got a new riser and changed the oil two more time seems ok. Not sure if it will last but it’s working now
 
All I'm saying is that the port side elbow is subject to very similar conditions as the starboard elbow...If one has failed, the other can't be far behind.

So, you can repeat the nominal 3 week exercise you just went thru or you can mitigate it...until the next maintenance cycle (4-6 yrs in the future)...
 
Oh yes. We put new risers and manifolds both sides. The one that we installed on stbd side had two holes in it(new) sent it back and received another new one, installed and no issues
 
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