The car water tank is right in front of the engine, except for the rear-mounted engine, which is directly behind the grille facing the wind on the front face of the car. It is composed of an upper water chamber, a lower water chamber, a heat dissipation pipe strip and a heat sink outside the pipe strip. The water pump on the engine pumps the hot water into the water chamber and cools it through the heat pipe. The water tanks are in front or behind the fan, because the fan dissipates heat to the water tank, so you can find the water tank when you find the fan.
There are no signs on the water tank itself, but there are usually signs on the water filler port. Many have warning signs such as opening with caution and being careful about burns, and some have signs with a thermometer and steam spraying out around it. Some draw an open book and an exclamation point. There are all kinds. Add long-lasting antifreeze to the water tank. It's basically antifreeze now. In addition to antifreeze, antifreeze also has many functions such as antirust. It's not a big deal to add a small amount of tap water. Just ask the repair shop to check the freezing point of the antifreeze before winter. If you add too much water and the freezing point is not enough, replace it.