Cleaning a Diesel Particulate Filter (DPF) is necessary when the filter becomes clogged with soot and ash, typically when the vehicle's automatic regeneration cycles (passive or active) are insufficient to clear the buildup. While professional off-car cleaning services exist, one method involves manually cleaning the DPF while it is still installed on the vehicle.
Manual DPF Cleaning with Chemical Treatment
When automatic regeneration processes are unable to clear the DPF, it often requires manual intervention. This involves using a cleaning treatment specifically designed to tackle stubborn soot and ash accumulation.
According to the reference, "In these cases, the DPF must be manually cleaned by adding a cleaning treatment to loosen and dissolve the soot and allow it to pass through the filter."
This chemical treatment helps to break down the deposits that are blocking the filter channels. Once applied, the loosened material can then pass through the filter, allowing exhaust flow to improve and potentially restoring DPF function.
How is the Treatment Applied?
The cleaning product needs to be introduced directly into the D DPF structure. The reference outlines two common ways this manual application is performed:
- Through the Pressure Sensor Tube: Many DPF systems have pressure sensor ports. These ports can be used as access points to inject the cleaning solution into the filter housing, allowing the liquid to saturate the DPF material.
- By Removing a Sensor: Alternatively, a sensor, such as an oxygen (O2) sensor or a temperature sensor located near the DPF, can be temporarily removed. The opening left by the sensor provides a direct entry point to apply the cleaning product onto the face or body of the filter element.
Applying the product directly ensures that the cleaning agent makes contact with the clogged sections of the filter, maximizing its effectiveness in loosening and dissolving the trapped soot.
Why Manual Cleaning?
Manual cleaning is typically considered when diagnostic codes indicate excessive DPF blockage (high soot load) that active regeneration attempts have failed to clear. This method is often a less expensive alternative to complete DPF replacement or professional off-vehicle cleaning.
It's important to note that the success of manual cleaning can depend on the degree of clogging and the type of deposits (soot vs. ash). Ash, which is non-combustible, cannot be burned off by regeneration or dissolved by some cleaning agents and may still require professional intervention or DPF replacement if the ash load is too high.
Manual cleaning using a chemical treatment aims to restore the DPF's ability to regenerate effectively or at least postpone the need for more extensive service or replacement.
