Radiator
A heat exchanger used to transfer thermal energy from the engine coolant to the air flowing through it, cooling the engine.
The radiator is the main heat exchanger in a vehicle's cooling system. Located at the front of the vehicle behind the grille, its primary job is to transfer heat from the hot engine coolant into the atmosphere, keeping the engine operating at a safe, regulated temperature.
Hot coolant flows from the engine block into the radiator's inlet tank. It then travels through a network of small, flat tubes surrounded by thin aluminum fins. As the vehicle moves, air flows through the radiator's grille and past these fins, absorbing heat from the coolant. When the vehicle is stationary or moving slowly, electric radiator fans pull air through the radiator to maintain cooling efficiency. The cooled fluid is then pumped back into the engine.
Radiators can fail due to external debris blocking the fins, internal scale buildup blocking the tubes, or corrosion causing leaks. Since modern radiators are constructed with aluminum cores and plastic side tanks, cracks at the plastic seams are very common.
Signs of radiator failure include engine overheating, visible green, orange, or red coolant leaks under the front of the vehicle, a low coolant warning, and sludge or discoloration inside the radiator. A failing radiator must be repaired or replaced immediately to prevent severe engine overheating damage.