What is a DPF - Find out here what a DPF is before purchasing your new modern diesel engine, but for those of you who have purchased a DPF vehicle already, it is best to arm yourself now with all the information you need so that you don’t end up spending £2500.00+ on repairs. Using the information on this site, you could correct all future problems for just a fraction of that price and future-proof the safety of your vehicle.
So - What is a DPF?
The Diesel Particulate Filter (DPF) is integrated into modern diesel engine exhaust systems, designed to trap and safely remove particulate soot matter from the exhaust gasses of diesel engines. The aim of the filter is to remove a minimum of 80% particulate soot matter from the diesel engine exhaust gasses before they exit into our atmosphere.
What is a FAP?
The DPF is also referred to as a Diesel Particle Filter and a FAP (Filtre à Particules). The term FAP comes from the french diesel cars, mainly Peugeot & Citroen which have been fitted with this technology since 2000.
The DPF is like a big honeycomb ceramic filter inside, similar in ways to a catalytic converter – except the holes are much smaller and square not circular. As the exhaust gasses flow through it, the DPF captures the harmful molecular diesel particulate (soot), which is in size a thousandth of a millimetre. Once the DPF has reached captured soot levels of between 25-45% the on-board engine management system will activate a “Regeneration Cycle” which increases the exhaust temperatures to burn off the soot inside the filter so that it is removed safely.
When the DPF requires regenerating (self-cleaning) you need to refer the owners manual of your vehicle for specific driving instructions to successfully carry out a regeneration. In general, the DPF warning lamp would be illuminated and you are required to drive on a dual-carriageway / motorway for at least 20 miles at a constant speed of 40-50mph in 4th gear until the warning lamp goes out. The warning lamp will only go out once the DPF Regeneration has been completed successfully.
There are many setups manufacturers have chosen to get the best possible results from a regeneration cycle and to make it as successful as possible. Some of these setups include:
- Additive Fluid Systems
- 5-Cylinder Engines
- 5th Injector in Exhaust
- Pre-Cycle & Post-Cycle Injection
Some vehicles will use one of the above and some will use a combination to try and find the best solution to regenerating a blocked DPF.
Not in all cases is it possible to complete a successful DPF regeneration and there are many factors which can affect this process. Once a DPF is blocked beyond a successful regeneration, you could be looking at hefty repair bills – it is not unheard of to be spending £2500.00 to correctly put your vehicle back on the road. A recent customer told us that she had just purchased her vehicle and was stung straight away with a £3000.00 repair bill:
I purchased my 2006 Mazda 6 2.0D from a local car dealer and a few days after the DPF light started to flash. I asked the local dealer “What is a DPF?” and I was told it’s just a filter in the exhaust and to clean it I need to drive on the motorway – I did this and the light went off. Three weeks later it was back on and I was advised to take it to Mazda. After investigations I was told the repairs to get me back on the road would cost me £3000.00 and there was no guarantee the car would be perfect – I asked Mazda “What is a DPF?” and they told me it is the root cause of the problems and maybe if I knew what a DPF was, I would have understood the vehicle was not suited to me and my local runs.
The problem here is you only ask “What is a DPF” when you’ve come into contact with the DPF problems.
The term “What is a DPF” is searched for 49,500 times a month on Google (as of April 2013) and is a growing concern for motorists. We offer free impartial advice and hope to help motorists around the world resolve all their DPF related issues without spending £1000′s. If you’re vehicle has been affected and would like to know what is a DPF then you’ve come to the right place – please share this website to help others understand what is a DPF. We welcome any comments and stories you may have about your DPF related problems.