DPF Filter Maintenance: How to Keep Your Diesel Running Smoothly

Short journeys and diesel engines don't mix well. Here's how to prevent DPF problems before they start.

The Diesel Particulate Filter (DPF) has been fitted to most diesel cars sold in the UK since 2009. It captures soot particles from exhaust gases, reducing harmful particulate emissions. However, DPFs are one of the most common sources of diesel car problems — and the issue is almost entirely preventable.

How Does a DPF Work?

As soot accumulates in the DPF, the filter becomes gradually blocked. Periodically, the engine management system initiates a 'regeneration' cycle — injecting extra fuel to raise exhaust temperatures high enough to burn off the accumulated soot (around 600°C). This regeneration is automatic and usually happens on motorway or A-road journeys where exhaust temperatures are sustained.

The Problem with Short Journeys

Short journeys — to school, to the supermarket, around town — never allow the engine to reach the temperature needed for DPF regeneration. Soot accumulates faster than it can be burned off, and eventually the DPF blocks completely. This triggers a warning light, causes power loss, and often puts the vehicle into limp mode.

How to Prevent DPF Problems

Take your diesel car for a regular motorway run of at least 20–30 minutes at 2,500 rpm or above
Use good quality diesel fuel — some low-cost fuels have higher soot-producing properties
Keep up with your oil change schedule — the engine management system uses oil quality data to manage DPF regeneration
Don't ignore the DPF warning light — early intervention can prevent the need for expensive replacement

Is a Diesel Right for Your Driving?

If your driving is exclusively urban short trips, a diesel with a DPF may not be the right choice. Modern petrol hybrids or mild hybrids may be a better fit for city-focused drivers. If you already own a diesel, understanding DPF management and following the prevention steps above will extend your filter's life significantly.

PKA Automotive offers professional DPF cleaning for diesel vehicles. In many cases, forced regeneration or chemical cleaning can clear a blocked DPF without replacement. Contact us for advice.