helping a friend of mine with a 496 std started getting water in the oil @ 40 hours, marina pulled it apart(1 head) said it was a leaking head gasket, volvo jacking him around because the boat is a little over 2 years old, he was told he had a 5 year warranty...anyway have they had issues with head gaskets on these ?? thanks Rob

Quite a few 496's both Mercury and Volvo had some head gaskets issues as they are both built and assembled by GM Powertrain as a base engine with stock GM head gaskets. The question to ask here though is has the engine ever experienced an overheat from any issue in the past or did an overheat happen at the time of the head gasket failure. any significant overheat on a marine engine with composition head gaskets can suffer head gasket leakage and failure. If no overheat has ever occured during its life then the head gasket failure would be a simple part failure and its replacement should be covered under a valid warranty.

Best Regards,
Ray @ Raylar

no overheat...I ran the boat some of the time....sat most all of its life....3 years old....40 hours, 10 or more of those are the dealer moving the boat to winter storage every year...