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The radiator is the primary component of the engine cooling system, and with the support of the thermostat, it regulates engine temperature. A radiator successfully keeps the vehicle’s engine cool, which in turn helps prevent it from overheating. Radiators often contain a separate internal heat exchanger to cool automatic transmission fluid.



How Does it Work?

  • A radiator is connected to channels running through the engine and cylinder head, through which a coolant liquid is pumped.
  • Coolant carries the heat away from the engine as it flows, and radiators transfer the heat from the fluid inside to the air outside. This allows the fluid to cool, which then cools down the engine.

How Is It Made?

  • Most modern cars use aluminum composite radiators, where the core is aluminum and the side tanks are reinforced plastic.
  • These radiators are made by brazing thin aluminum fins to flattended aluminum tubes.

Why Does It Fail?

  • Failure to service the coolant is a primary reason for failure. As coolant becomes more acidic over time, it consumes the aluminum core from the inside out.
  • Age is a common culprit in the final days of radiators.
  • Heavy use and being exposed to the elements wear down radiators.
  • Corrosion, salt and humidity cause a radiator to fail over a period of time.
  • When corrosion or contamination starts to form, it will slowly decrease the radiators capabilities until it breaks down completely.
  • Collisions can also cause radiator failure, especially if the underhood becomes tighter due to impact.

What are Symptoms of Failure?

  • Puddles of coolant.
  • Sweat smell under the hood.
  • Overheating engine.
  • Leaking coolant.
  • Radiator sludge.

What Are the Consequences of Failure?

  • Car overheats and produces steam/smoke.
  • Bad thermostat.
  • Electric fan no longer comes on.
  • Failed head gasket.
  • Bad seal between radiator cap and expansion reservoir, or too much air in system after fluid change.

If you have questions or concerns about radiators or any of your vehicle’s components, come into your local Pep Boys where we can answer any question, help you find any part, or perform any vehicle service you might need.