Blue Print has produced a list of the top selling Diesel Particulate Filters in its specialist Asian and American vehicle components range and issued some useful information on the importance of timely DPF replacement.

A blocked DPF is often the result of failed active or passive regenerations caused by driving style and conditions, and can also be due to failure of other components such as those in the EGR system. Ordinarily, pressure sensors will detect a DPF starting to block at around 45% blockage and at this point the vehicle will attempt ‘active regeneration’, which is a process to burn off the soot and clear the filter.

To do this a vehicle has to be driven at a constant throttle for a set period of time such as a motorway run. During regeneration the EGR system is closed to increase the oxygen content and a secondary burst of fuel is fired into the cylinders just after combustion, which then enters the DPFs ceramic core and super-heats it to around 500 degrees Celsius and burns off the soot deposits.

If a vehicle only ever does short ‘stop – start’ journeys, such as in a pure urban driving cycle, the ‘active regeneration’ process is never completed and the DPF blockage will not clear. At approximately 75% blocked, the DPF warning light will come on and the vehicle may go into limp mode. Blue Print says at this point it may be possible to do a ‘forced regeneration’ using an advanced diagnostic tool such as its G-Scan. If the light is ignored then the filter will soon become completely blocked and will have to be replaced.

The failure of a DPF is usually the symptom of a problem elsewhere in the engine. These issues can include problems surrounding; the EGR system, over cooling, airflow meter, fuel system, or worn turbo charger. Basic service items such as air filter replacement and the correct oil can also cause DPF issues.

Blue Print’s expanding range of Diesel Particulate filters includes 31 parts numbers covering 44 applications. The tops selling Blue Print DPF’s and hence cars where DPF’s often need replacing are;

• ADM560505 – Mazda 3 1.6DT 2003>
• ADT360501  –Lexus IS 2.2DT 2005>2010
• ADM560501 – Mazda 6 2.0DT 2002>2008
• ADG060502 – Kia Sportage2.0DT 2005>2010
• ADH260502 – Honda Accord 2.2DT 2008>
• ADG060505 – Hyundai Santa FE 2.2DT 2005>2010
• ADG060504 – Hyundai Tucson 2.0DT 2004>2010, Kia Sportage 2.0DT 2004>2005
• ADM560502 – Mazda 5 2.0DT 2005>2010
• ADN160503 – Nissan Qashqai 2.0DT 2007>2010
• ADC460501 – Mitsubishi Shogun 3.2DT 2006>

Blue Print DPFs come with a 3 Year Warranty. It should be noted that this covers manufacturing defects and not blockages caused by an engine producing excessive soot. Blue Print says even a brand new DPF can become blocked in as little as 100 miles if a running issue isn’t spotted and rectified before filter fitting.