05-11-2013, 05:45 AM
The Cummins 315 you are talking about is a 5.9 liter. They are parent bored and do not have sleeves. I can't think of any way for the salt water to get into the oil unless from the exhaust or if both seals on the seawater pump have failed ( not likely). The oil cooler is on the closed loop with antifreeze.
Do the valve springs show any signs of rust?
Do the valve springs show any signs of rust?


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