PWR radiator

[nissannewby]

so is a coolant level or flow sensor different than a water temp gauge. and if they are different wouldn't a temp gauge tell you loss of coolant eg. water pump failure or split radiator hoses etc.

Yes they are different. A temp sensor requires coolant around the probe to give you an accurate reading, if there is no water in there you can cook them without the gauge reading anything close to hot as is not a air temp probe.

A level sensor will alert you when the coolant is at a predetermined low point, you can then get out and check for any leaks, hose ruptures etc well before you do any damage to your engine. A flow sensor obviously reads flow, so if there is no water there is no flow, or if the water level is low flow is reduced.

A level sensor is probably a cheaper and easier to install/setup option.