Genuine VW/Audi 4H0121251B Radiator – Audi | AU4H0121251B

• AU4H0121251B

Radiators help regulate your Audi engine’s temperature and keep it within its optimal operating range. It is made up of two tanks which can be metal or plastic, connected by metal tubes with fins attached to direct air across the tubes called a core. Coolant circulating within the engine absorbs the engine’s heat, bringing down the engine’s temperature. This hot coolant then flows into one of the radiator’s tanks. It is pushed through the core of the radiator, where heat from the coolant is passed to the air flowing through it, reducing the temperature of the coolant before entering back into the engine from the opposite radiator tank.

Most radiators are located at the front of your Audi behind the grille. The radiator’s position makes the radiator core susceptible to damage from the debris from the road. Debris can also clog up the radiator core tubes, restricting the coolant flow.

Radiators should be replaced if leaking, if the core tubes are clogged internally, or if the external core fins are clogged with debris. Due to the ease of the radiator core air fins being bent, it is not recommended to clean out the fins as it often causes the fins to bend and restrict airflow.

Replacing the radiator in your Audi is usually a straightforward process. However, it often requires the removal of the radiator hoses, engine cooling fans, and radiator fan shroud to access the radiator mounts and remove the radiator. Replacement of the radiator hoses and thermostat is recommended with the radiator to ensure proper cooling system function. In addition, bleeding of the cooling system to remove any trapped air is vital for proper coolant flow and cooling system operating pressure and function.

Audi Radiators.