What is the reason for coolant leakage in the BMW 3 Series?
3 Answers
The reason for coolant leakage in the BMW 3 Series is a damaged radiator, and the solution is to replace it with a new one. Coolant is designed to prevent the freezing of the cooling liquid during cold winter parking, which could otherwise crack the radiator and damage the engine block. Its full name is antifreeze coolant. Many people think that coolant is only used in winter, but in fact, it should be used all year round. Taking the BMW 3 Series 2021 Modified 320i Sport Package as an example: this car is manufactured by BMW Brilliance, classified as a mid-size car, with a gasoline energy type, an 8-speed automatic transmission, a 4-door 5-seater sedan body type, and a top speed of 222 kilometers per hour.
I've driven a BMW 3 Series for several years and have dealt with coolant leaks myself. Common causes include cracked or aged radiator leaks, especially in older vehicles where plastic components tend to become brittle. Loose or ruptured hose connections are also frequent issues since coolant pipes are made of rubber, which degrades under prolonged high temperature and pressure. Water pump failure is a major concern - it's responsible for circulating the fluid, and once its seal wears out, leaks occur. Additionally, thermostat issues or poor radiator sealing can also lead to seepage. If you notice pink or green liquid stains on the ground, immediate inspection is crucial, otherwise engine overheating may damage the cylinder block, doubling repair costs. I recommend checking coolant levels every six months, topping up when low, as regular maintenance can prevent these troubles.
I remember in my early years driving a BMW 3 Series, the coolant leakage was particularly noticeable in winter, with puddles always forming under the car. The main cause was often aging and cracked hoses, as BMW's cooling system is precisely designed but the materials aren't resistant to freezing cracks. A faulty water pump shaft seal could also lead to leaks, especially after high-speed driving. A less common issue was problems with the engine cylinder head gasket, where high temperatures caused sealing failure. Don't underestimate this problem—low coolant levels can cause the engine temperature to skyrocket, even leading to engine seizure. Later, I developed the habit of checking the coolant reservoir monthly and replacing substandard brands with standard blue coolant. A simple method is to check the temperature warning light on the dashboard before starting the car; if it's abnormal, stop driving and get it checked.
