Vetus M3.28 Engine concerns

[Dysan669]

Hi all

Got a question around my new to me 31ft boat, she came with a newish Vetus M3.28 diesel in seemingly good condition.

Since day one it felt to me the engine was running hotter than it should, although I have not had any issues with it while using the boat.

I did a complete service on the engine, including removing the heat exchanger and cleaning out all the tubes, I also flushed the cooling system and replaced the antifreeze and bled the cooling system. New impeller and OEM o-rings all round.

I have strong water flow at the exhaust outlet, but that water is ice cold, the same as the cold Atlantic ocean water the boat sits in.

Also if I look at how the hoses run it does look like there is no way for the ocean water to exit the exhaust if it does not run through the heat exchanger

Does anyone know if the water coming out the exhaust should be warm? Obviously it should not be hot but currently the heat exchanger get so hot you cant touch it, while the egress water is cold, this does not seem right to me.

Also I can feel the antifreeze moving around the engine when pressing on the coolant hoses, and they do get hot to the touch, so seemingly coolant is moving around the engine.

Any other suggestions where I can maybe start looking for a problem?

[Pete7]

The obvious one is the thermostat. Did you replace it?