Diesel fuel filters play an essential role in protecting fuel systems and components within engines from damage. Recently, however, there has been an increase in vehicles breaking down from blocked filters. Although only affecting less than 0.1% of light duty diesel vehicles last year, it is a concern as, not least, it is an inconvenience to motorists and investigations are ongoing as to the cause. This website provides information about the problem and is also a means for those affected to record details about their breakdown to aid with investigations. 
The fuel and automotive industries have been working hard through a coordinated BSI taskforce, to try to understand the cause(s). The evidence gathered has not, as yet, indicated any solution that can be recommended to eliminate the problem. The taskforce will continue to work until the issue is resolved.
Through the Department for Transport we are supporting the efforts to understand and find a resolution and would like to gather detailed information from any motorists affected by this issue. Please get in touch by completing the following survey www.smartsurvey.co.uk/s/dieselfuelfilterblocking. All information you provide will be treated confidentially and will only be used to help identify the cause of fuel filter blocking in diesel vehicles. We are very grateful for your support.
This website provides information to motorists who have experienced breakdown as a result of diesel filter blocking. Click on the link below to see our Frequently Asked Questions page.

                                Frequently Asked Questions

Advice if you experience a breakdown

  • The diesel fuel filter is fitted to protect the complex fuel and engine systems of modern diesel vehicles. Blocking of the fuel filter, although inconvenient, indicates that the fuel system has been protected from potential, more severe and more costly, damage.
  • Please make a note of the date, time, location and circumstances of the incident, and if possible obtain information detailing the most recent fuel fill-ups and vehicle servicing so that the DfT and industry can gather as much information as possible.
  • Any advisory notes issued by the breakdown service attending your vehicle would also be beneficial to the investigation.
  • After you experience a breakdown through a blocked diesel fuel filter, please visit your dealer or garage to make sure your diesel fuel filter is replaced as soon as possible, if this was not done at the roadside.

General advice on diesel motoring

  • Ensure the diesel you purchase conforms to the British Standard, BS EN590. Most fuel retailers selling to this standard will make reference to the British Standard on their fuel dispenser. If the fuel dispenser is not marked please check with the retailer that it conforms to BS EN590.
  • Certain Diesel fuel properties are modified across the year to ensure optimum performance in all conditions. Winter grade diesel has properties that help ensure that your vehicle will operate effectively in lower temperatures. It is generally available at forecourts from the 16th November. If you are a limited mileage driver, it is good practice to make sure your tank is filled with winter grade diesel at the earliest opportunity to ensure the best protection in cold conditions.
  • Servicing of all vehicles to the manufacturers’ schedules to ensure they are operating in the optimum condition is generally recommended. Always make sure that it includes the diesel fuel filter being changed within the manufacturer’s recommended service periods. This is good practice for the efficient operation of your vehicle, however, is not guaranteed to protect the vehicles from this particular problem.

The information and advice on this website is provided with the support of: