The future of DPF servicing

Change can seem shocking at first, but is it the future?

By Frank Massey | Published:  08 May, 2017

Two months from now will bring my tenure in the motor industry to 49 years. I would like to think I have evolved, kept up with technology, enabling me to provide a professional service, enjoying customer respect and integrity. My focus has been the technical challenges, while my son David manages the commercial responsibilities.

This creates a wide role for me developing our training programme, internal research and development, bringing the focus of this topic to technical and legal compliance.

My chosen subject here is diesel servicing and repairs, specifically particulate filtration and emission control. It is something we have been passionate and vocal over for several years. it gives me no pleasure or satisfaction in seeing our prediction over the demise of diesel vehicles.

Diesel fudge

The future is now clear as to the changes our political lords and masters have in mind. This gives us a short timeline to get our house in order. My intention is to advise, help and warn what will happen if we all continue to fudge diesel particulate repairs as we currently do. Upwards of 90% of independent garages will fall into this category. How do, or should we service and recover diesel particulate filters? The choices are very simple!

1. Replace with a new OE filter

2. Replace with a non-OE filter

3. Clean and service off vehicle in factory controlled conditions

4. Clean and service off the vehicle in house

5. Clean and service on the vehicle

6. Remove the filtration system from the vehicle

Here is the problem; we as professional repairers are legally and financially responsible, and exposed for the advice and decisions we make. This is the case even if the customer agrees and or instructs us on a certain course of action.

Clear legislation is in place for the performance and fitment of diesel emission systems. Vehicle taxation is based on specific emission levels agreed with the manufacturers. I am sure I do not need to mention VW and Audi, but I will bet their corporate accountants have regrets. How long do you think it will be before the government bean counters look at us? Let's not fool ourselves enforcement will take the effect of stringent fines.

Everything

So what are we doing wrong? Pretty much everything. Please remember my words, help, advice and not critique.

We are breaking the law in removing legally compliant systems. MOT examiners will lose their licence by passing unauthorised emission system modification. You will become the first unpaid enforcers.

We are breaking the law further in polluting the water course, by power cleaning, or rinsing out cleaning agents into the drains. Utility companies have powers to set huge fines and often do.

We are also in breach of the clean air act by using some of the available cleaning agents that require the running of the engine whilst emitting all the contaminants back into the environment.

It is quite possible at this point some of you are about to rip out the magazine pages and offer an alternative use for them. Please reconsider, we are slowly killing ourselves.

Let's as an industry get together, think ahead of the curve and get our house and process in order.

Change

I recently visited CERAMEX in Slough, and before a handful out there suspect a paid endorsement here, I even paid my own travel expenses. I have been aware of several companies offering off vehicle cleaning, pressure washing, thermal cleaning in an oven, and ultrasonic treatments. My problem has always been, is the catalytic converter and DPF still fully functional and durable when refitted? How can we protect ourselves from future premature failure due to other indirect causes? Can we provide certification of test results?

Here is my opinion as to how we should address the blocked, cleaning DPF problem. Many of you will not agree, I do not care, this is how it should and eventually will be done. Reflect on the vast changes in the paint refinishing industry before you cry never!

The DPF is initially visually examined bar coded and weighed, attached by means of bespoke plumbing to what is in effect a big dishwasher (sorry Marcus my words) then filled with water. A short pause here, some of you will know water damages and degrades the precious metal wash coat. The purified water has all the damaging trace elements removed and is only used to restrict the clear DPF passages. Pressure waves, are then sent through the core, XPURGE for several minutes. I did question if this was in effect an ultrasonic process? This is not the case. The water does act as a transport mechanism for the waste material, including ash, which is flushed out, into a waste tank. The water is filtered, for reuse and the semi solids captured in large skips for reprocessing. It is pure carbon it would make an ideal fuel source!

The DPF core is then placed in electric air dryers where apart from drying the core, measurements are taken for flow rates and back pressure. Next a two-stage photograph examination is applied to detect face off and ring off cracking to the core. A second weight check is taken to ascertain the mass of soot ash removal. The next service is optional for small vehicle units, the cat and DPF are subject to a sample hot gas bench to establish the reduction of, CO/HC, finally being placed in a particulate bench where filtration is assessed and measured.

Certification

Certification and bespoke transport packaging completes the service. The recovery success is consistently above 90%. The cost is approximately half the cost of a new OE unit. No environmental pollution so your grandchildren will thank you and may avoid the huge increase in paediatric respiratory illnesses.

You will earn profit from a professional repair, enjoy the respect and integrity it brings, however not all customers will agree or want to pay, and that is not our problem.

Further information

Please contact Annette 01772 201 597, enquries@ads-global.co.uk for further information on upcoming training courses and events.

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    Recently we were presented with a BMW X3 for poor performance and a suspected DPF fault. After interrogating the customer we gathered all necessary information. Initial diagnosis confirmed multiple fault codes and a blocked DPF. Determining what caused the DPF to block is vital for the correct diagnosis and preventing reoccurrence. We created a test plan to test each fault and separated them into faults that affect the performance, faults that can cause the DPF to block or prevent regeneration and ones that don’t. In order to fully test the vehicle we would need to clean the DPF first as the exhaust back pressure was so high, the vehicle was barely drivable. As a member of the DPF Doctor network we have a very successful method of cleaning the soot from the DPF without the need for removal and access to many manufacturer-specific tips with DPF faults. The information and knowledge within the DPF Doctor network has proved to be invaluable and has given us an outstanding success rate. With our test plan ready we were able to calculate a sensible labour figure to conduct the tests required. The customer authorised the labour and the DPF clean.

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  • Inject some knowledge  

    At the heart of fuel delivery is the injector. If there is a single focus point that has helped reduce emissions and boost performance it’s the injector. Despite this, we don’t pay it enough attention, and I include myself in this critique. Let me qualify this by asking a rhetorical question; How many of you have injector bench test capability?

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    Current ramping also changed to peak and hold with peak values of around 4-amps. For the time being things stabilised, with little or no obvious common injector problems. The next challenge manufacturers faced was to reduce the internal mass of the injector components. In plain English they got smaller, lighter, less robust, and with lead free legislation less reliable. Remember Fiat iaw injectors?

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  • It CAN be done! 

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    Ruling out
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    Added pressures
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    Full analysis
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  • Issues of rotation 

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    Endurance testing
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