Where is the coolant added in a BMW 320?

[AubreyLynn]

BMW 320's coolant filler port is located on the left side of the engine. Excessive coolant consumption: Radiator damage, poor sealing of the upper and lower water chambers leading to coolant leakage; loose connections or poor sealing at the reservoir, water pump joint surfaces, and various coolant system pipe fittings causing coolant leakage; cylinder head gasket damage, excessive flatness deviation or warping of the cylinder head and block mating surfaces, and loose cylinder head fastening bolts allowing high-temperature, high-pressure gases to enter the cooling system, resulting in rapid coolant loss. Functions of coolant: Raises the engine coolant's "boiling point" (temperature at which coolant boils), lowers the coolant's "freezing point", typically has a service life of 1-2 years, and special test strips are available to measure coolant concentration.