Modern BMW Diesel Engines now have a particulate filter that has been designed to reduce the ‘black smoke’ emissions. These filters work by collecting the soot particles produced from the burning diesel which is normally incinerated when the filter becomes hot enough. However over time the filter can become blocked if subjected to unfavourable driving styles or ECU remapping. This leads to degraded engine performance and faults displayed in the instrument cluster.
There are two ways the BMW can overcome this. One is passive regeneration; whereby regular sustained driving speeds above 40 mph will produce the temperatures required to maintain the filter. The second is active regeneration, where the vehicle will calculate the load on the filter and assess various parameters to schedule a regeneration cycle, which works with day-to-day town driving. Active regeneration will only work when the engine has no detrimental faults to ancillary systems. It will not indicate such faults but will isolate the active regeneration, which will block the filter.
Many garages offer expensive alternative “fixes” that include various removal methods or chemical solutions. Please be advised that changes to the MOT this year could render your car as a failure if you decide to have the filter removed. There is absolutely no need to have the filter removed!
The average cost of repair for a filter is normally around £1,500, so be sure it is faulty first!
BMWMAN can investigate, rectify and force regeneration of the filter, clearing the blockage and returning the engine back to its former glory! We have successfully regenerated every filter that has been blocked. Our service will surprise you! Please contact us for details.
