The responsibility of transferring the engine heat to the atmosphere is that of the BMW Radiator. It can be found in the front grill area of your BMW and is connected to the engine by way of radiator and coolant hoses.
Once the coolant leaves the engine it enters the radiator through the top opening. It then proceeds down through the small channels that are situated vertical in this component. As the coolant passes through them the heat in it is transferred to the metal channels. There are fins situated on the exterior of the channels that allow for the heat to dissipate easily as air flows over them.
The most common problem with a BMW radiator is not a leak emanating from it, but the channels in the core of the unit becoming clogged with sediment. The sediment that builds up in the radiator is from the dissolved solids that are present in the water and coolant that is the liquid medium used by your vehicle for cooling purposes.
With an annual flushing of your coolant system on your BMW, the sediment buildup in it can be removed before any damage or clogging of the channels can occur. This flushing of the coolant system is done by placing a water hose in the top of the radiator so the system can be filled while it is running. The hose coming from the thermostat housing has to be removed so the coolant can be removed as it leaves the engine. Once this coolant appears to be clear, the system is flushed. The lower coolant hose is then removed and the entire system is drained of its contents. With all of the hoses reattached and the system on your BMW is refilled with fresh coolant, your vehicle is ready for the road once again.