The space inside the Nissan radiator core is the reason this device has the ability to disperse the heat that the engine is producing. Inside of the radiator core mounted to the front of your Nissan are literally hundreds of small channels. It is this large amount of surface area that makes it possible for this cooling system component to transfer the heat from the engine coolant to the radiator and out into the surrounding atmosphere. The coolant enters the radiator core from the top, and the channels are stacked inside the core so the coolant can flow via means of gravity to the lower part. In the process of flowing through the core, the coolant is allowed to give off the heat is has collected. If the channels in the Nissan radiator core begin to plug up and become smaller, this flow is reduced. The most common reason for the reduction in the size of the channels in a radiator core is due to buildup of sediment. This sediment is from the dissolved solids that are present in the water used in the coolant system. The only procedure that reduces this sediment buildup is called a radiator flush. If this flush is not done on an annual basis, the channels will continue to build up until the radiator core can no longer dissipate enough heat from the Nissan engine to cool it sufficiently so it can operate as it was designed to. The radiator flush is just one of the periodic maintenance procedures all Nissan owners must have completed on their vehicle to keep it properly operating. This is also the best way to reduce the cost of repairs by maintaining the components so they can last as long as possible and still function properly.