[Closed] How does the temp gauge on a car measure temperature?

it's the water,

If it's the water, that's not good.. Cos I've just found out I haven't had any in there for a while.

Ooops..

That's not good, is it.

It's from the water.

No it's not good. Not good at all. You really could be looking at a ****ed head gasket at least, maybe worse, lots worse.

This is why you should check your car over regularly, even a new one.....
Oil, water, tyres (Condition and pressure) and lights once a month at least.

but remember, just cause the bottle is empty that you fill up, doesn't neceassairly mean there is no fluid in the system atall.

But its not the best to have it run low, an engine without coolant will heat up to the point of damage in minutes, even at idle.

PP - don't forget to take the car to pieces and grease it all 😉

... with vaseline.

So you've not had an engine temp. light come on, on the dasbhoard then?
I wonder if the bulb's gone or been removed?

What car is it?

It takes the water temperature by the thermostat near the radiator.

So if you've got a leak (or if the water pump is bust) the temperature will show up as low but the engine may be overheating. If the heater doesn't work at all, that too is a symptom.

It (was) a 1987 Toyota Camry station wagon with only 330,000kms on the clock. It died on the way to the airport early on Saturday morning, me having foolishly decided that, despite having a massive hole in one of the coolant pipes, it 'might just make it'. It didn't. I think various whirring bits of metal may have melted and catastrophically fell to bits, before engine oil went pissing about everywhere and I had to leave this smoldering heap on the side of the highway. Ooops.

I think that if I'd dissassembled the engine and carefully smothered all moving parts with lots of grease beforehand, it may have just made it though. 😥