This case concerns a BMW diesel examined at BEM-TEC. Vehicle identifiers have been removed and images are illustrative.
Replacing the DPF alone does not fix the cause
The particulate filter had already been replaced but clogged again. Diagnostics found a glow-system fault, an EGR malfunction and an air-mass measurement fault. These can affect whether the correct conditions for regeneration are met.
What should be checked before another regeneration?
- engine management fault codes and stored operating conditions
- glow system operation
- EGR and air-mass measurement operation
- exhaust back pressure and DPF loading data
- engine temperatures and regeneration requirements
Why investigate first?
If the underlying fault remains, a new or cleaned DPF can load up again. We therefore investigate the cause before replacing parts or repeatedly forcing regeneration.