qsm11 405hp

[tye vecchione]

hello
I have a qsm11 with the lower 405hp rating with 8000 hours. it is in a commercial scallop boat with a 3to1 gear and is more than enough power for the application.
upon return from a 20 hour trip this morning, I noticed oil in my overflow coolant bottle. I know everyones first thought is head gasket but this motor has never ever gotten hot, its raw water cooled and I have never seen it go above 182 degrees. the boat is a non planing novi boat aka a 8 knot boat. the 8 knots is achieved with about 1360 rpms therefore is never run above that except once in awhile to make sure she will turn up.
im hoping it is the oil cooler but I believe I would have seen coolant in my oil after I shut the boat down and the pressure remained on the coolant side and pushed coolant into oil if the leak was in the oil cooler.
I am really having a hard time believing it could be the head or head gasket for reasons I already stated and obviously would prefer to not pull the head.

Topic

[Gregory]

What was the result of the oil in the coolant.  Head or oil cooler?

Greg

 

[tye vecchione]

yes there is oil in the main expansion tank as well as the overflow bottle and the engine is heat exchanger cooled with a sea water pump. I will get some pics tomorrow.
it is hard to gauge how much oil since when a paper towel id dipped into the tank it comes out covered. if you use a turkey baster to withdraw the coolant it does not seem like nearly as much oil

[Tony Athens]

QSM11 questions

Overflow Bottle————How much oil?

How about the main expansion tank?

When you say “raw water cooled” , you mean HX cooled and you have a seawater pump, correct?

Post some pics of the engine showing all.

[Author]

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