DPF Regeneration & Blocking

DPF's can become blocked with contaminants produced during the normal operation of a diesel engine. These consist of two main components: soot based particulate matter and ash.

Particulate Matter

Particulate matter, also known as soot, is produced by all diesel vehicles and consists of small particles of carbon. This carbon based particulate matter can be removed by a process known as regeneration which burns off the carbon deposits and restores the flow through the filter. Most vehicles are fitted with regeneration systems that operate without user intervention.

Ash

Ash is a standard by-product of the combustion process that takes place in diesel engines. Unlike particulate matter, the ash that accumulates in filters cannot be burned off by regeneration processes and requires periodic cleaning in order to maintain the efficient operation of the filter and the engine.

Exotherms

A blocked filter leads to an increase in back-pressure and deterioration in engine performance. In severe cases, the exhaust gas flow becomes so restricted that the filter can be permanently damaged (burnt-out or ‘exothermed').

Servicing Alerts

Vehicle manufacturers will provide guidance on the recommended cleaning frequency of a vehicle's DPF but this can vary depending on the usage of the vehicle and its duty cycle. DPF cleaning or replacement can be performed as part of routine planned servicing.

Many vehicles fitted with DPF's have a warning light that informs the operator when the filter needs cleaning, based on an increase in the exhaust back pressure detected by the engine. Failure to clean the filter will produce a significant deterioration in engine performance and fuel consumption; this can permanently damage the filter.