What are DPF Filters, and How Do You Avoid Problems?



Diesel trucks are more efficient than their gasoline-fueled counterparts. Diesel truck exhaust, though, is laden with tiny soot particles called PM particulates. PM particulates are known carcinogens and one of the primary components of urban smog. 


Diesel truck exhaust also contains high levels of carbon monoxide, nitrogen dioxide and assorted hydrocarbons that are highly hazardous to human health.


Diesel particulate filters (DPF) are exhaust after-treatment devices that aim to decrease hazardous diesel emissions. DPF filters are not mandatory throughout every jurisdiction in the U.S., but an increasing number of states are requiring heavy trucks that are powered by diesel to be retrofitted in a way that will reduce particulate matter emissions by 85 percent of more. Retrofitting engines with DPF filters satisfies this requirement.


How Do DPF Filters Work?


Your DPF filter is a ceramic device that contains thousands of tiny, honey-comb-shaped channels and openings. The filter’s walls are lined with catalysts like platinum or palladium. As exhaust streams into the filter, soot is trapped on the filter’s walls. Dorman and Dinex are two companies that manufacture DPF filters, and you can find these parts through truck parts suppliers, such as Find It Parts.


Motor vehicles with DPF filters require engine oil that’s low in sulphur and low in ash. Using the wrong type of oil in your truck can cause your DPF filter to malfunction.


DPF Regeneration


Over time, the DPF filter will become clogged with soot. This soot needs to be burned off through a process known as DPF regeneration. There are two types of DPF regeneration:


• Passive regeneration: Passive regeneration takes place when you’ve been driving your truck for a long time on an open highway so that your engine becomes hot enough to burn off the soot.


• Active regeneration: Active regeneration is typically performed by a trained mechanic. The mechanic will run the engine in a controlled environment at a high enough temperature and for a long enough period of time to clear the soot.


What Are the Signs of a Blocked DPF Filter?


You may notice one or more of the following symptoms if your DPF filter is blocked:


• Higher idling RPMs

• Lower gas mileage

• Foul-smelling engine exhaust

• Problems starting your truck


You may be able to jump-start the regeneration process by avoiding congested city traffic and driving at high speeds on an open road. This will raise exhaust temperatures so that the soot residues can clear. Otherwise, you may need to take your truck to a mechanic.