bleeding water hoses

[tommyh]

I recently changed the water return hose on my 5411, its the one that connects to the underside of the thermastat and returns to the seacock via the tee at valve.
My motor always ran extreamly cold with the gauge hardly moving, after changing the hose i noticed an increase in temp to around 140 or so.
My question is; is their air in the system now causing the slight increase in temp or was the old hose blocked or restricted and my system is now working as it should.
The thermastat and pump are new and all is in order as far as the rest of the system.
If it is air how do you bleed it, could i remove the hose and fill it with water before reinstalling.
I took the boat out and ran under load for an hour or so and it stayed aroud 140 the whole time.
Am i on a witch here or is all COOL.

[sartorst]

Sounds like your temp guage was not working but is now, 140 is OK, is it raw or fresh water cooled 140 is ok for raw water cooled

[Lepke]

Some thermostats come with a very small hole to allow air to pass thru. When filling the fresh water cooling on a cold engine, the thermostat is closed and without the hole, air remains. However, when the thermostat opens with heat, that should allow the air to escape to the highest point.
It really sounds like the old thermostat was either stuck open or opening too soon.

[cabo_sailor]

Sounds kind of cool to me. Shouldn't it be closer to 170-180? If you have one of the IR thermal probes, you can spot check temps. I'd pay particular attention to the thermostat housing.

Had a guy at the marina completely tear down his cooling system. Gage showed overheating within 5 min of start. Way too fast especially with good water flow. Turned out to be the sensor. Now I always have an IR probe. About $40 and works great on the grill 😎


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