Prolonged idling of a diesel engine and short trips with frequent stops can make it harder to clean the particulate filter. If the cleaning cycle is interrupted, some of the soot remains in the filter.
Diesel particulate filter: why short trips may not be enough
The diesel particulate filter (DPF) traps particles from the exhaust. During regeneration, the accumulated soot burns off at high temperature. If the driver shuts off the engine before the cycle is complete, cleaning is interrupted. When this repeats, the filter can become clogged.
«A long traffic jam and a few blocks after it may not give the filter time to complete cleaning. If the DPF indicator has come on, the driving mode should be checked against the instructions for your model,» explains the author Oleksii Astapov.
When only the yellow DPF indicator is lit, Volkswagen advises driving for at least 15 minutes at a speed of 60 km/h or more, maintaining 1,800–2,500 rpm.
EGR valve: how deposits interfere with its operation
The EGR valve returns part of the exhaust gases to the intake. According to MAHLE data, soot from the exhaust and oil mist form deposits on the valve. Over time, they can prevent it from fully opening or closing.
