How a Diesel Particulate Filter Works

  • Passive Regeneration

    Passive DPF regeneration is designed to take place automatically on main roads at higher speeds, when the exhaust temperatures are high

  • Owner Action

    Passive regeneration requires no specific action from owner, other than trying to build into their journey plans some regular higher speed extra-urban journeys
    Ask for low-sulphur oil during routine servicing

  • Active Regeneration

    When the ECU calculates soot loading in the DPF to be typically 45%+ the dashboard DPF symbols lights up Carry out and active regeneration as per owners manual

  • Owner Beware

    Excessive regeneration attempts is indicative of other problems
    Always refer to a garage or professional mechanic Oil dilution will occur during regeneration, which may increase oil change frequency

  • Professional Diagnosis

    Continued and increasing frequency active regenerations may be down to urban driving style, or a vehicle fault.
    A full test and diagnosis is required to eliminate any potential mechanical or electronic problems

  • Forced Regeneration

    If the diagnostic checks show no mechanical, or electronic failure, then a forced regeneration will need to be carried out to try and reduce soot levels within the DPF

  • Soot -v- Ash

    Soot is combustible and can be burnt off, leaving ash as a by product.
    Ash, by definition is incombustible and must be removed from the DPF through an off-vehicle cleaning process

  • Garage Tip

    If soot levels are excessively high, or there is high ash content then forced regeneration will not work
    Continued attempts may cause damage to the engine, if the back pressure is too high

  • Assisted Regeneration

    To help clear excess soot from the DPF, chemical additives are available
    These normally work by reducing the regeneration temperature and only clear soot, not the ash

  • Professional Solutions

    DPF Specialists combine detailed diagnostic with assisted regeneration
    This has a much better chance of clearing soot, rather than shop brought DIY miracle cures

  • Garage Tips

    If the DPF soot levels are excessively high and/or the vehicle mileage is +80,000 then its highly likely that’s the ash levels are high too.
    The best solution is for the a professional clean off-vehicle.

  • Garage Beware

    Emissions from forced regenerations are harmful and must be completed away from public areas
    Static regeneration’s could be in violation of the Clean Air Act

  • Off-Vehicle Cleaning

    High ash levels, causing DPF blockage cannot be removed by regeneration or any chemical process. The ONLY way to restore the DPF is to remove it and have it professionally cleaned off-vehicle

  • Cleaning Process

    Professional off-vehicle cleaning is a highly sophisticated process that safely cleans and restores the DPF filter by aqueous backwashing, drying and testing, combined with advanced diagnostics

  • Cleaning Success

    Off-vehicle cleaning is 98%+ successful in restoring the filter to virtually new condition Professional off-vehicle cleaning centres typically guarantee the clean for 12 months guarantee

  • Replacement DPF

    It’s highly likely a blocked DPF can be fully cleaned and restored
    However, if the DPF has a damaged or broken core, then the filter must be replaced