What does it mean when the Audi A4's engine keeps running after turning off?
2 Answers
Because the water temperature inside the engine hasn't dropped immediately, the radiator fan continues to operate for cooling. Once the appropriate water temperature is reached, the fan stops. In other words, even after the car is turned off, the fan may still be working. More details are as follows: 1. The car has an automatic cooling function: After parking, if the engine temperature is too high, the fan will automatically turn on to continue cooling the engine. Once the engine temperature drops to a reasonable level, the fan will stop automatically. 2. A "pop pop pop" sound from under the car: Some owners might hear a "pop pop pop" sound from under the car after parking and turning off the engine. The "culprit" is actually the three-way catalytic converter located at the rear of the vehicle's chassis. This component operates at temperatures close to 1000 degrees Celsius, and after turning off the engine, the metal parts inside expand and contract due to heat, producing some popping sounds. 3. The role of the three-way catalytic converter: It is a purification device in the exhaust system that converts harmful substances in the exhaust into carbon dioxide, water, and nitrogen, reducing harmful gas emissions.
As an automotive enthusiast who has specifically studied Audi models, including common series like the A4, I can tell you that when the engine keeps running after you've turned it off, the most common reason is the cooling fan still operating. This is not a malfunction but a safety mechanism. In the Audi A4, if the engine temperature is high when you shut it down, the fan will continue to run for a few minutes to dissipate heat, especially in turbocharged versions where the turbo needs cooling. Additionally, electronic systems like the water pump may still be operating. However, be alert to abnormal sounds, such as grinding or continuous noise, which could indicate a faulty fan motor or electrical issues. It's advisable to park in a safe location and check for signs of overheating. If this happens frequently, it's best to use an OBD scanner to check for trouble codes or visit a professional workshop. Never attempt to disassemble the fan module yourself to avoid damaging components.
