Diesel Particulate Filters

Monday, 27th May 2019

The Diesel Particulate Filter, (DPF) which is fitted as standard to all diesel engines aged 2009 onwards, is designed to remove soot from the exhaust gases before they are emitted into the atmosphere.

The DPF is designed to be cleaned regularly, via the cars management system, through a process called regeneration. The accumulated soot is burnt off at high temperature (around 600 degrees c) to leave only a residue of ash, effectively renewing or regenerating the DPF.

When a DPF blocks or does not fully regenerate it will require the DPF to be cleaned to allow regeneration to take place.

An engine which is used in accordance with the manufacturer’s guidelines should never require the DPF to be cleaned, however most vehicles are used for different purposes and lengths of journey, which will affect the efficiency of the exhaust system. Vehicles which are used on motorways or high speed driving rarely need DPF treatment as the particulates are burned off and do not clog the filters. Conversely, vehicles used for frequent short journeys at low speed do not reach an effective operating temperature which ought to burn off the sooty deposits which inevitably over a period of time build up within the DPF.

In addition to the DPF being clogged as a result of the driving style, there could be other faults which are not related to this and can block the DPF. eg faulty pressure sensor. If the DPF is blocked the signs to look out for are as follows:

  • The dashboard DPF symbol to illuminate and alert you to a problem       
  • The on board control system to go into limp mode
  • The performance of the vehicle to be noticeably sluggish
  • Poor starting
  • Increased fuel consumption
  • Smokey exhaust
  • A general lack of performance

At Robertson Gemini Ltd we have the full range of treatment on offer ranging from:

  • Simple additives that are regularly directly poured into the fuel tank which in theory flushes the system. In some instances the system may well benefit from regular use of a DPF cleaning additive. The additional cost of the additive may be compensated for by the improved MPG achieved due to fewer regenerations having to occur. There is also the potential of increasing the service life of the engine oil.
  • A more sophisticated treatment is also available where a carbon cleaning solution is injected into the exhaust system via the DPF pressure line. When the treatment is added the engine is run at fast idle allowing the soak fluid to clean and then flush the carbon content in the DPF. Quite often there are underlying reasons as to why the DPF warning light is activated but before we initiate and DPF clean via the pressure line we carry out an in depth diagnosis, checking that the key components and sensors are functioning properly.

Before you take any action or choose any potential solution come and speak to the technicians at Robertson Gemini Ltd for free advice, they will inform you which of the options is appropriate for your DPF problem.

The DPF Team at Robertson Gemini Ltd:- 01556 502560

VAT No. 263 3371 68  •  Registered in Scotland SC144441  •  FCA No. 749058

Robertson Gemini Ltd is authorised and regulated by the Financial Conduct Authority, FRN: 749058. Registered Address: 96-98 Cotton Street, Castle Douglas, Dumfries & Galloway DG7 1AN

We act as a credit broker, not a lender. We work with a number of carefully selected credit providers who may be able to offer you finance for your purchase. Whichever lender we introduce you to, we will typically receive commission from them (either a fixed fee or a fixed percentage of the amount you borrow). The lenders we work with could pay commission at different rates. All finance is subject to status and income. Terms and conditions apply. Applicants must be 18 years or over.