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Diesel Particulate Filters
Date Listed: 21/12/2011
It’s the job of the DPF to trap soot (unburnt fuel) from a diesel engine and prevent it from entering the atmosphere.
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 another component such as the EGR system.
Ordinarily, pressure sensors will detect a DPF starting to block (45% blocked) 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 (several minutes). 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, the ‘active regeneration’ process is never completed.
At approximately 75% blocked, the DPF warning light will come on and the vehicle may go into ‘limp home’ mode. At this point it may be possible to do a ‘forced regeneration’ using an advanced diagnostic tool such as Blue Print’s 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:
• EGR system
• Over cooling
• Airflow meter
• Fuel system
• Blocked air filter
• Worn turbo charger
• Incorrect engine oil
• Driving style and conditions
Please note that Blue Print’s 3 Year Warranty covers manufacturing defects and NOT blockages caused by an engine producing excessive soot. A brand new DPF can become blocked in as little as 100 miles if a running issue isn’t spotted and rectified before fitting a brand new DPF.
Blue Print now catalogues a range of 10 Diesel Particulate Filters for popular applications.
Kia Carens – 2006>
Kia Sportage – 2004>2010
Honda CR-V – 2007>
Mazda 3 – 2006>2009
Mazda 6 – 2008>
Nissan Navara D40 – 2005>
Lexus IS220d – 2005>