A diesel particulate filter (DPF) is a type of filter that catches and then stores exhaust soot from a diesel engine to reduce the amount of emissions that engine creates. However, it’s important to remember that these filters have a finite capacity—you need to regularly empty out the trapped soot for the DPF to continue working as intended.

The process of cleaning out the filter involves cleanly burning off the excess soot that’s in the filter in a manner that reduces the harmful emissions associated with diesel exhaust, preventing the black smoke that occasionally can be seen emanating from diesel vehicles while they accelerate. There is legislation in place mandating the use of DPFs to help lower emission rates. In fact, removal of the DPF in a vehicle can result in a fine in some circumstances.

With all this in mind, here is some information about cleaning a DPF from a company that specializes in diesel engine repair in Corpus Christi, TX.

How do I know if I need to clean my DPF?

Before you actually begin cleaning your DPF, you need to know if it’s necessary. If the DPF starts to become clogged up with soot or you have a fault that begins to develop in the system, there should be an orange light that appears on your dashboard indicating the DPF requires service.

The DPF tends to get clogged up if you’ve been making short journeys at relatively low speeds. This is why diesel vehicles aren’t typically found in more urban environments—sure, you’ll see diesel trucks out on the highways and open roads, but they aren’t especially suitable for crowded city environments. A lack of ongoing maintenance and service will also result in a DPF getting blocked up sooner than it should.

How do DPF cleanings work?

The process of cleaning a DPF involves ensuring it’s capable of fully regenerating when it fills up with soot. This can occur in the form of either passive or active regeneration.

Passive regeneration occurs when a car has been running at speed on long journeys in such a way that allows exhaust temperatures to reach higher levels, allowing them to cleanly burn off all the excess soot located in the filter. Drivers are advised to regularly drive their diesel vehicles for 30 to 50 minutes at sustained higher speeds on roadways to clear out the filters through passive regeneration.

When this type of driving isn’t a possibility, active regeneration is the best means of cleaning out the DPF. In this process, extra fuel gets injected automatically as part of the vehicle’s engine control unit when the filter reaches a predetermined limit to raise the exhaust temperature and burn off excess soot. You can tell active regeneration is occurring if you notice cooling fans running, a slight increase in the amount of fuel being consumed, increase idle speeds, changes in engine notes or hot, acrid smells coming from the exhaust.

For more information about cleaning a DPF, contact Coastal Diesel Injection or visit us to discuss diesel engine repair in Corpus Christi, TX.