A recent Mercedes owner visited our garage here at A1 Diagnostics arriving with a common problem faced by many diesel vehicles. The ‘DPF’ needed cleaning. Here is the vehicle pictured below:
What is a DPF? I’m glad you asked. The ‘DPF’, or ‘Diesel Particulate Filter’, is a small part that has a big impact on a diesel vehicle’s emissions as it cleans the output from the engine before it passes out of the car, removing heavier diesel particles and lowering carbon impact.
Virtually all modern diesel vehicles have a DPF, and it’s been required by law since 2009 as a way of tackling the fuel’s dirtier side. However, all this good work catching diesel particles means the filters need cleaning from time to time, as they fill up with particles and become less efficient.
Signs that your car or van has a clogged DPF can vary. Sometimes vehicle owners will see a helpful warning light on the dash – this is the best symptom and it’s worth getting the problem resolved at this stage to avoid any of the more annoying symptoms which follow! Fuel consumption can increase if the DPF performs inefficiently, and with prices where they are at the moment, no one wants that. Soot can build up in the tailpipe, and this one is an easy check for vehicle owners: simply run your finger around the inside of the pipe and if there is soot, you know your DPF needs a wash.
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More severe cases can cause a vehicle to accelerate more slowly (requiring more power which in turn causes more blockage of the DPF), and at its most inconvenient, clogged DPFs can cause an engine to enter limp mode. To avoid these outcomes, it’s best to bring the vehicle in and get our team of mechanics to clean the DPF for you.
There are two methods of cleaning: on-car and off-car. The first approach leaves the DPF in situ and sprays a chemical through the filter to break down the diesel particles and clear the blockage. The second method involves removing the filter from the vehicle and cleaning it in a special machine. This latter method is more frequently required on modern vehicles, and it makes sure that all residues are removed from the filter before returning it to the car.
A combination of water and special cleaning fluid is sprayed under pressure through the filter from both directions, ensuring that both sides are cleaned and optimised. Once the cleaning is complete, the machine force-dries the filter and performs a pressure check and diagnostic assessment. These verifications are guaranteed with a 12-month warranty, so you know your DPF is good to go.
Once the cleaning and drying is finished, the reinstalled DPF undergoes a final diagnostic scan and the vehicle’s ash/soot values are reset so they can continue to monitor the DPF’s performance accurately.
In the case of our Mercedes Benz, the vehicle had a successful DPF clean and diagnostic assessment, and the owner was able to drive away in full peace of mind. If you would like our team to assess the condition of your diesel vehicle’s DPF, call A1 Diagnostics today and we’ll be happy to help.
