In the cooling system, there is an important part named radiator hose or may say cooling system hose, and it is designed to stop the engine from overheating. When your car is running, the radiator hose carries coolant through the radiator and engine to keep it working in a proper temperature. There are two radiator hoses in the system, and they are located in the upper and lower connecting to two radiators respectively. Here are some signs demonstrating your radiator hose is failing: if the A/C or heater doesn't work well; if the coolant is leaking; if the steam comes out of the engine compartment; if there are bulges or cracks in radiator hose, you need to buy a brand new one to replace, or it does damage to your engine. We offer BMW genuine OEM radiator hose with a discounted price.