DPF Diagnostics in Tyne and Wear

A diesel particulate filter traps soot from the exhaust. When it fills, the engine management burns the soot off in a process called regeneration. If conditions are not right for that, or a part of the system fails, the filter clogs and a warning light appears.

At Banks of the Tyne in Hebburn, DPF diagnostics is about finding the root cause. Cleaning and repair work are covered on their own page, and the choice depends on what the tests show.

Signs that point to a DPF problem

The warning light is the usual first sign, but there are others.

• A DPF or engine warning light on the dashboard
• Limp mode, with the car feeling short of power
• Higher than usual fuel use or a fan running after you park
• A smell of hot, burning exhaust after a journey
• Oil level rising, which can be linked to repeated failed regenerations

What diagnostics involves

We read stored fault codes and live data, including the pressure difference across the filter and exhaust temperatures. This tells us how blocked the filter is and whether regeneration is happening. We then check the sensors, the wiring and any related components, because a faulty pressure sensor can mimic a blocked filter.

We also look for causes upstream, such as injector faults, EGR problems, turbocharger faults or oil consumption, since those can load the filter with soot faster than it can clear.

What affects the outcome

Driving pattern is a major factor. Regular short trips stop the exhaust getting hot enough to clear the filter. The condition of the engine matters too, because a fault that produces extra soot will keep clogging a cleaned or new filter.

Diagnosis separates a filter that can be cleaned or regenerated from one that is damaged, and from a fault that sits elsewhere. That helps you avoid paying for a new filter when a sensor was the problem. Ask us what the results show and what we recommend.

What to do when the light comes on

If the DPF light appears with no other symptoms, a sustained run at steady speed on a suitable road can sometimes help the filter clear, as your handbook describes. Do not keep ignoring it, as a blocked filter can lead to more serious and costly damage.

If the car goes into limp mode, the oil warning appears or you notice smoke, get it checked soon. Repeated attempts to regenerate can dilute the engine oil in some cars.