How Much Coolant Should Be Added to a BMW 3 Series?
3 Answers
BMW 3 Series requires 4 liters of coolant. Coolant is a special additive-containing liquid primarily used in liquid-cooled engine cooling systems. It offers excellent performance in preventing freezing in winter, boiling in summer, and inhibiting scale and corrosion throughout the year. How to Replace Coolant: Before completely replacing the coolant, conduct a thorough inspection to check for any signs of leakage or cracks in the pipes, with a particular focus on the five-way hose. Coolant flows through the five-way hose and is then distributed to different parts of the car to function. If there is any leakage of coolant in this section, replace the hose or re-secure the connection as necessary. Drain the old coolant and then flush the liquid channels with clean water. Add clean water to the coolant reservoir and continue to pour water into the reservoir, allowing it to flow continuously through the engine cooling system. Then, start the engine and let it idle for 3 to 5 minutes to circulate the water. Initially, the water flowing out of the reservoir will have a faint pink color. Continue adding clean water until the water coming out is clear. Note: Remember to remove the heater hose and drain the water from the heater core. After draining for about an hour, add the new coolant through the radiator hose. Then, pour another container of coolant into the coolant reservoir until it is nearly full. Start the engine and let it run for about 10 minutes. At this point, as some air is expelled from the cooling system, the liquid level will drop slightly. Add more coolant until it reaches the "MAXT" mark on the reservoir.
I've been driving a BMW 3 Series for several years. The coolant is usually filled to about 7 to 8 liters of the cooling system capacity, depending on your model year. For example, the E90 generation may require 7 liters, while the newer G20 generation may be closer to 8 liters. When adding coolant, don't do it when the engine is hot. Instead, wait for the engine to cool down, then open the radiator cap or expansion tank and fill it up to the line marked MAX. Avoid overfilling to prevent overflow. It's best to use BMW-recommended coolant types, such as blue or green, with a 50% water and 50% coolant mix ratio. This ensures both freeze protection and prevents engine overheating. If the coolant level drops quickly after a recent change, there might be a leak or airlock in the system, which needs to be checked. If you're doing it yourself, it's easy to make mistakes, so I recommend using genuine OEM parts for refills. Generally, it's advisable to replace the coolant every two to three years to maintain performance and safety.
The amount of coolant added is crucial for the BMW 3 Series. I understand that the total capacity of the cooling system is generally around 7 liters. When adding, there's no need to fill the entire system—just check the expansion tank level when the engine is cold and fill it up to the maximum indicator line. It's recommended to use genuine BMW coolant because it's specifically designed for aluminum engines and offers strong anti-corrosion properties. Incorrect additions, such as too much or too little, can lead to engine overheating, reduced efficiency, and wasted money. Regularly checking the coolant level is simple—just a quick glance each time—and combining it with oil change maintenance can extend the vehicle's lifespan. If you're unsure about the model or quantity, consult the owner's manual or look for information on BMW forums, where many enthusiastic car enthusiasts will share their practical experiences.
