6bta cummins raw water leak

[Fem Karras]

Hi all , need help .I have been getting salt water coming into my port engine (1992 6bta 300hp) ,  practices of elimination i purchased from Sbmar the following water pump kits for both engines , after speaking to tony i changed the aftercoolers (which needed doing , cause i had the old sealed units ) to the sbmar aftermarket ones. i flushed motor a few times and put new oil, cruised around for a full day checked oil and everything was fine. left boat on pontoon for several weeks , went to start it. it wound over like it had a flat battery started and ran fine i checked dip stick to find it had a slight white tinge in the oil which indicates water. i have owned the boat for 7 years and have never serviced the exhaust elbows , on removal and inspection i have seen there is quite some pitting and a small weap hole on the end of the elbow towards the outlet (i cant say this is the problem) but i think they will need replacing anyway.  far shot do you think because it was on my pontoon facing port side to traffic , some of the large vessals going by could pressurize water through the exhaust outlet up into the turbo to engine? It has a lift muffler in it. 

Cheers Fem      

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[Fem Karras]

Thankyou Clark I will investigate further 

cheers  

[Clark Leighs]

Yes, about large vessels forcing water into the exhaust.     This has been discussed before.  It all depends upon the wave size but if wind is also hitting the transom that would not help.  I almost missed this, the size AND frequency of the waves may hold water from previous waves with each of the next wave adding water untill it enters the engine.

 

A flapper cover of the exhaust system exit may help but I would also put a small weight on that flapper to ensure it stays in place.   

 

A long term repair would be to look through and study Seaboard  , Tony Athens Tips, section about exhaust systems to prevent this from happening again.      

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