Engine coolant temperature alarm

[cmedsailor]

The instrument panel of my engine, a Volvo Penta MD2030D, has an engine coolant temperature alarm. Is this alarm only supposed to sound if the raw water supply stops for some reason (eg damaged impeller) or will it also sound if there’s a leakage/drop of the coolant fuel? In other words will any drop of the coolant increase its temperature for the alarm to go off?
Thanks

 

[Bobc]

It will sound if the coolant temperature exceeds the set limit.

 

[rob2]

It isn't perfect and will signal some things and not others. Bear in mind that the sensor is using the coolant as the medium to transmit the temperature onto it, so a drop in level that means it is no longer immersed may in fact disable it considerably. It cannot measure the level at all, although the level may affect it.

Rob.

 

[VicS]

The instrument panel of my engine, a Volvo Penta MD2030D, has an engine coolant temperature alarm. Is this alarm only supposed to sound if the raw water supply stops for some reason (eg damaged impeller) or will it also sound if there’s a leakage/drop of the coolant fuel? In other words will any drop of the coolant increase its temperature for the alarm to go off?
Thanks

As Bobc says

It will sound if the temperature setting (95C) is exceeded at the sensor position ( lower part of the heat exchanger ?)

This may be due to inadequate raw water flow, fouled heat exchanger, full or partial loss of engine coolant.

I would not expect it to sound if the coolant level remains above the heat exchanger tube stack but at some point below that there will be insufficient cooling and it will sound.