If your diesel’s DPF (diesel particulate filter) warning light is on — or the dash is showing “exhaust filter overloaded”, an anti-pollution fault, or the car has dropped into limp mode — the DPF is almost certainly blocked. It’s one of the most common problems we see with diesl cards and the usual cause is simply how the car is driven: DPFs clean themselves on longer, faster runs, so a diesel that lives on short local journeys never gets hot enough to regenerate, and soot builds up until the filter clogs.

The warning signs

• DPF or engine management light
• Noticeable loss of power
• Car in limp mode
• Worsening fuel economy
• Sooty black smoke from the exhaust.

How we fix it

We start with a proper diagnostic check to confirm the DPF is the problem and measure how badly it’s blocked — soot loading, pressure readings and any related faults, because a failed sensor or a lazy EGR valve can also be the problem. Depending on what we find, we then carry out a forced regeneration using dealer-level equipment, or an on-vehicle chemical clean for filters too blocked to regenerate. Both are done at your home or workplace.

Once it’s sorted, we’ll explain how to keep it that way, and for diesels doing mostly town miles, regular servicing with the right grade oil makes a real difference. Persistent warning lights of any kind are covered by our mobile diagnostics service.

Get your diesel breathing again — contact our mobile mechanic covering Chelmsford and we’ll come to you.