Cooling System

The radiator is the primary heat exchanger, transferring engine heat to the atmosphere through its core of fins and tubes. When buying a used radiator:

• Inspect the core for bent or crushed fins (reduces cooling efficiency, but minor damage is acceptable) and for corrosion or green staining around the tanks (indicates seeping)

• Check plastic tanks (common on modern radiators) for cracks at the neck, fittings, and where the tanks crimp to the core — these are the most common failure points

• Confirm the connection sizes (upper/lower hose diameter and position) match your vehicle

• Aluminum-core radiators are preferred over older copper/brass units for weight and cooling efficiency

Always flush and use the correct coolant type (check your owner's manual — mixing coolant types can cause gel formation and clogged passages).

The core support is the structural frame that holds the radiator, AC condenser, and cooling fans. Replace after front-end collisions that bend or crack the support. Verify all mounting holes for headlights, hood latch, and bumper brackets match your vehicle before purchasing.

Radiator/Condenser Fan Motor Assembly

The electric fan motor assembly provides airflow through the radiator and AC condenser at low speeds and while stationary. The assembly typically includes both the radiator fan and the AC condenser fan on a common shroud. Confirm the mounting frame matches your vehicle's radiator dimensions. Fan motor speed and direction are controlled by the ECM — the motor itself is typically plug-and-play if the connector matches.

Mechanical Fan Blade and Fan Clutch

On rear-wheel-drive vehicles with belt-driven cooling fans, the fan blade bolts to the fan clutch, which mounts to the water pump hub. These two components work together and should be replaced as a pair when either fails. A failed fan clutch that does not engage causes overheating at idle; a fan clutch that is locked up causes excessive noise, reduced fuel economy, and can damage the water pump bearing.

Fan blade direction matters — confirm the blade pitch moves air toward the radiator (not away from it) before installation.

The water pump circulates coolant through the engine and radiator. Failure modes include seal leakage (wet spot below the pump), bearing noise (grinding or whining from the front of the engine), and impeller slippage (overheating despite good coolant level). Always replace the water pump gasket and thermostat when replacing the pump. On timing-belt-driven water pumps, replace the pump whenever the timing belt is replaced — the pump is accessible at that point, and worn pumps fail shortly after belt service if left in place.

The coolant reservoir maintains proper fluid levels as the system cycles through temperature changes. Cracks or a missing cap (which maintains system pressure) cause coolant loss and air ingestion. The cap pressure rating must match your system spec — a cap with too low a pressure rating causes coolant boilover at normal temperatures.