Getting To Know Your Diesel Particulate Filter

Many diesel car owners have a diesel particulate filter (or DPF) fitted to their vehicle. What does it do? How does it work? Read our getting to know your diesel particulate filter guide now…

What is a diesel particulate filter (DPF)?

DPFs have been fitted to all new diesel cars since 2009 when the Euro 5 standard came into force. The purpose of the diesel particulate filter is to collect and remove soot from the exhaust when the diesel is burned in order to avoid harmful emissions being released.

What is passive and active regeneration?

A DPF needs to be emptied regularly in order to work at its optimum level. This can be carried out through a process called “passive regeneration” which means that when the exhaust reaches a high temperature (e.g. on motorways), the collected soot is burnt off, leaving only a small amount of ash residue.

For those drivers who don’t complete the right type of journeys for passive regeneration to kick in, vehicle manufacturers incorporate “active regeneration”. When the Engine Control Unit (ECU) senses that the filter is getting blocked it injects additional fuel into the engine in order to increase the exhaust’s temperature. If active regeneration is occurring, you may notice the engine sounds slightly different or hear cooling fans running. Active regeneration takes place at around 300-mile intervals and takes five to ten minutes.

How do you know if there is something wrong with the diesel particulate filter?

A warning light will usually flash up on the dashboard if there is an issue with the DPF. If you drive over 40 mph for around 10 minutes, it should complete an active regeneration cycle and clear the warning.

Can I remove the DPF?

If you remove the DPF filter from the vehicle, then it will fail its MOT and could invalidate your insurance policy as the vehicle will be illegal to use on the road.

Call Car Clinic MOT Centre Ellesmere Port Garages now for a free no obligation quote and book a summer Ellesmere Port car servicing appointment for your vehicle at the same time. Car Clinic MOT Centre Ellesmere Port helping you stay safe this summer!