DPF/particulate filter

Once a DPF becomes full it needs to run a regeneration cycle. If the vehicle is doing lots of short trips it won’t have an opportunity to run the regeneration cycle—and the filter will become clogged.

Once a DPF becomes clogged it can prevent the regeneration cycle from running. The only option then is to either manually clean the DPF (which doesn’t always work) or replace the unit.

To ensure that you vehicle has opportunities to run a regeneration you should occasionally complete a long drive at a high speed (40 minutes at 100 km p/h, once every few weeks.)

It is also worth noting that emission/exhaust system problems can be difficult to diagnose. To avoid misdiagnosis, we recommend having your vehicle’s problem diagnosed by an specialist BMW technician.

All late-model diesel BMWs are fitted with a diesel particulate filter. The DPF is used in diesel engines to reduce emissions—which it does by capturing particulate matter (soot) from the exhaust gas.

Once the DPF become full with soot, it uses the heat from the exhaust to oxidize/burn off the soot—converting it into less harmful carbon dioxide and water vapor. This process is called a ‘passive’ regeneration—and the car typically needs a long drive at high speeds (freeway driving) to perform it.

Diesel BMWs can also launch what is called an ‘active’ regeneration—which needs to be initiated with a scan tool. This process works by injecting additional fuel during the exhaust stroke—which unburnt—then oxidizes in the exhaust system, raising the temperature to force a burn.

Within each model generation there can be different types of DPF for the same engine code. The variations can be attributed to a range of factors, including emissions standards.

The best way to determine fitment compatibility of a DPF is to match the BMW part numbers from the catalogue. This can be done by decoding your vehicle’s VIN in a BMW EPC (electronic part catalogue.)

If you don’t have access to an EPC, provide our team with your vehicle’s 17-digit VIN—and we’ll check our stock for a compatible match.

DPFs are highly-interchangeable between models.