What does a submarine type light mean?

Answer 1

If by "submarine" you mean an icon that looks like a submarine's Periscope sticking out of the water, this is likely the coolant temperature warning light (it's supposed to be an old glass tube thermometer dipped into the water). This can mean your engine is getting too hot and needs to cool down, or you run the risk of causing severe damage. This can sometimes happen if driving in very hot weather and putting a lot of load on the engine.

Check if the coolant level is low. If you do need to add more coolant to the engine, drive it a round for a bit afterward and recheck the coolant level. If it is low again, you have a coolant leak which needs to get fixed PRONTO.

It is important that you do NOT open the coolant cap while the engine is still hot as heated coolant can often be under a lot of pressure and can spray very hot liquid everywhere, which can (and probably will) burn you if the cap itself doesn't.

If the coolant level is fine, and your engine uses an electric fan to draw air through the radiator, make sure the fan is going when the engine is running.

If this light comes on frequently, and the coolant level and radiator fan are both fine, you should take it in for service ASAP as something else is causing the engine to run hotter than it should.