BMW 3-Series Coolant Overflow Tanks

While operating, the engine produces a lot of heat that, if not dissipated, can cause overheating and failure of the engine itself and other underhood components. Therefore, there is a cooling system that decreases the temperature in the engine compartment. Inside the system, there is coolant, a mixture of antifreeze and water. This mixture also contains ethylene glycol, an organic compound which is harmful to the environment, so it is extremely important to prevent coolant from getting out of the cooling system. For this purpose, there is an expansion tank that keeps coolant from spilling onto the ground.

Typically, overflow or expansion tanks, exposed to heat and harmful chemicals, are one of the weakest points of the cooling system. BMW 3-Series expansion tanks are generally known to be made of plastic that is not so durable, so they fail rather often, putting other parts of the car at risk. If you have noticed coolant leaks, one of the first things to be inspected is the expansion tank. If it has cracks, replacement is necessary. Our BMW 3-Series coolant overflow tanks and components are made of high-quality plastic so they are more resistant to heat and chemicals than factory ones.