What is a Diesel Particulate Filter (DPF)?

What is a Diesel Particulate Filter (DPF)?

The diesel particulate filter (DPF), found in some Euro 4 vehicles and all Euro 5 and 6 vehicles, is developed to meet emission standards.

This filter, which is similar in structure to a honeycomb, traps solid particles harmful to the environment in the exhaust. However, the level of these particles trapped in the filter increases over time and can lead to reasons such as clogging. Pressure sensors measure the level of soot residue in the diesel particulate filter. When the critical soot level is detected in the filter, and the appropriate conditions are met, the regeneration process begins.

Sometimes, the vehicle cannot regenerate, and the soot level will prevent the engine from working efficiently. In this case, the DPF mark may appear in the car. When you see this warning, you should use the vehicle at a constant speed and high speed for a certain period.

In automatic vehicles, this can be done by moving the gear lever to the manual position. As the car starts to be used at high revs, the engine management system sends more fuel and increases the exhaust temperature. When the exhaust temperature reaches approximately 600 °C, the regeneration process begins, and the solid particles are burned and turned into soot. In some cases, this process may not work, the vehicle's DPF or Engine Malfunction Lamp does not go out, and the car loses power. In this case, you should take the vehicle to the service, and the regeneration process should be performed with the help of a fault detection device.

Generally, the DPF clogs for the following reasons:

  • Low-quality fuel,
  • Long-term use of vehicles at low speed and in stop-and-go traffic,
  • Running the car idle for a long time,
  • Use of oil in the wrong specification.

The DPF, which is present in all newly released diesel vehicles, may become unable to be cleaned even with the regeneration process if the necessary precautions are not taken and may need to be replaced.