I own a 2009 310 Sundancer with...

[Capt__Jim]

I own a 2009 310 Sundancer with 300 hp Mercruiser Axium engines. Recently I lost an engine returning to my slip after a long trip. I had my marine services company look at the engine and they discovered that salt water had entered one bank of the engine and caused the engine to seize. According  to them, the engine needs replacing as it is almost impossible  to remove all the salt. After draining the engine and cranking the starter, salt water continues to enter the cylinder. Risers and manifolds were removed for inspection and were found to be almost new. Anyone else have a similar problem? The engines have less than 500 hours on them but have always run in salt water.

[Steele_y_Tutz]

Head gaskets? Are they closed cooling or raw water?

[Capt__Jim]

Raw water with a fresh water flush system could be head gasket or cylinder head corrosion. Since it was filled with salt water, my marine service center says the engine is toast.

[Steele_y_Tutz]

With the corrosion it most likely is toast. The easiest is replacement. Other than that is rebuild with full machining. And that could end up being about the same cost as a new along with more time. It sucks to say the least. Was it sea water in all cylinders or just one or two? I would guess head gaskets as the exhaust looked new. I've had diesel head gaskets go bad in less than 200 miles. And it's never fun.

[Lary]

Lost 2 last year with about the same amount of hours
It’s BS
Check your insurance mine paid for both

[Capt__Jim]

I was able to locate a complete long block and I am having it shipped to my marine repair company. I should be back in operation in about a week. Asked them to fully check out the other engine so we can address any corrosion issues before they become critical. Thanks for the advise concerning insurance.