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.

Related Articles

  • Euro 6 SCR 

    With a focus on technical challenges and potential cost with diagnostic equipment and servicing, I think we should explore the technology that drives the need for specialist tools in both service and repair. I’m going to look at Euro 6 generation 2 diesel emission systems.

    I’m convinced that the more technology manufacturers throw at improving diesel combustion, the more problems they introduce. As usual, my knowledge is based on Volkswagen-Audi Group design. Engine design innovation is now closely following that of gasoline direct injection, alike to that of the EN888.


    MDB concept
    The VAG MDB concept engine design is a world based modular system. This allows for a more flexible production with regional variation based on local emission standards. The three basic modules are the intake systems, a central engine core based on the EN288, and the exhaust or emission module.

    The EN288 engine has 3-cylinder and 4-cylinder options with EU4/EU5/EU6 compliance. It is a cast iron block, alloy with the 3-cylinder variant, with and without balance shafts, crossflow alloy cylinder head with variable valve timing. A fully mapped and integrated coolant pump ensures maximum thermal efficiency.

    It important to understand that there are significant differences between the 2.0/1.6/1.4 3-cylinder and 4-cylinder design concepts, so various comments across the range of options will not reflect every variant.

    The 4-cylinder head has an offset valve layout. This introduces turbulence within the combustion chamber. The 3-cylinder valve layout is a conventional layout with swirl flaps in the intake module. Intake valve variation allows for a delay of intake valve closure (IVC) with a reduction of cylinder pressure during compression, reducing temperature and NOx. The control variator utilises oil pressure, with a backup accumulator to adjust IVO/IVC.


    Emission control module
    The emission control module is without doubt the most radical evolution. High pressure EGR is introduced via a valve directly from the exhaust manifold to the inlet, with the single aim of heating the 3way Euro 5 catalyst, or 4way Euro 6 catalyst when the engine is cold (see fig 1.)
    Low pressure exhaust gas passes via the EGR cooler, catalyst and particulate filter into the exhaust system. During NOx reduction strategies, exhaust gas is re-circulated aided by the EGR control valve and exhaust venturi or brake as it is referred to. This device partially closes the downstream exhaust circuit increasing upstream exhaust gas pressure by 30-40mb. This helps self-cleaning of the cooler and allows for AdBlue to be injected post cat pre DPF. Mixing is aided by the turbo. This also provides for the wideband NOx sensor to monitor NOx content before it enters the catalyst and particulate filter.

    The exhaust brake also increases the upstream exhaust gas volume through the cooler, aiding self-cleaning. In addition, the emission control module has the task of reducing ammonia NH3.

    Fuel delivery pressures have increased to 2000bar with delivery phases from 3/5/6 events depending on the operating profile. Additional combustion monitoring is achieved via a pressure sensor built in a heater plug. The sensor data helps the PCM calculate fuel quantity, timing and EGR values.

    There is also a feature I have supported for some time, relating to how the DPF is subject to regeneration or replacement based on saturation levels.

    Catalytic reduction
    4-way catalytic reduction, co, hc, NOx, nh3. is based on principles of absorption followed by reduction (see fig 2). This is assisted with noble metals; platinum, palladium, and rhodium. An additional ingredient, namely barium, is used to assist in NOx reduction. Barium also helps absorb sulphur requiring periodic de-sulphation. The PCM performs this process every 600mls by ensuring exhaust gas temperature around 600-650°C. This should take 15-20 minutes.

    The location of the cat and SCR has required copper zeolite to assist with higher operating temperatures. The additive injector is water-cooled to help protest both the nozzle and electrical circuit. The exact control of injector timing and additive quantity is a precise value based on the specific vehicle ID. To test the 5bar delivery pressure and two-way control valve in the additive tank module requires OEM software. Additive delivered into a calibration flask must meet exacting min-max values.

    We have also conducted tests on the variation in quality of adblue. I recommend either a SG test or refractometer ensuring 32.5% ratio of active agent and de-ionised water. We have seen large variations in agent quality. It should have little or no odour. Please note; a strong smell of ammonia should not be present.

    Performance
    I’m not insensitive to the improvements that diesel vehicles have attained. It’s just that they don’t perform as intended under actual road conditions. We find SCR additive consumption is often excessive requiring premature refill. Additive injector crystallisation and EGR cooler blockages are commonplace as well.

    Be careful when interpreting DTCs suggesting a blocked DPF. It can often be the cooler that is blocked,  restricting gas flow and affecting the algorithms for AMM, gas temperature, and DPF pressure. This will of course directly affect regeneration strategies.
    Returning to my initial opening thoughts, is it clear that the fiscal life of a vehicle, especially diesels, could be ended by the cost of a single repair. The future will I believe move very quickly within certain demographics to PCPs and rental rather than ownership. This is just what the manufacturers want.

    This means that in a shrinking market is even more vital to understand and invest in the latest evolutions.

  • Q5 and a pain in the ‘A’  

    I am a bit of an ‘old-skool’ mechanic, I enjoy working on vehicles that are mechanical and do not depend on computer wizardry to move. I regularly work on 1960s Porsches in all their air-cooled simplicity.
        
    Just last week though, a friend asked if I could service their 2017 Audi Q5. We arranged a date and off I went to pick this car up. This is a hugely impressive vehicle with every piece of technology you could ever want. Confidently, I got it up on the lift and started checking it; brakes, suspension, exhaust. I also let the oil out. Everything was going accordingly to plan at this point.
        
    I always make sure that when a car is still within its manufacturer warranty that I use genuine parts and oils, for me it protects the customer on any issues.
        
    For a car that was only two years old everything was as it should be. Unfortunately, this is when the headache started. I screwed in the new sump plug and lowered the car ready to put the oil in, but wait, no dipstick! Manufacturers now don’t include a dipstick. Is it weight-saving gone mad or a great idea from someone who doesn’t work on cars? Following this unhappy discovery, I researched and found out the quantity it should have, put that in and then checked the on-board computer. What a palaver.
        
    Next came the replacement fuel filter. The price of the thing was enough to put me off but I found the location, now at this point I had spoken to a friend who is more in tune with modern cars and stated that to replace the fuel filter you the needed to plug it in to a computer and prime it! The fuel filter replacement was then put on hold for another day when I could have the car back.
        
    Next on my list was to reset the service light, this too needed specialist diagnostic equipment for Audi vehicles. It wasn’t going well, I could sense it was going to be one of those days.
        
    Defeated by the technology of today, I decided to contact the owner and get the car back until I could call in a favour from a friend who had spent tens of thousands on diagnostic equipment.
        
    The icing on the cake to my disastrous and unproductive day was the service record. I normally relish the challenge of getting my service stamp within the lines and making sure that it is readable. It is a skill that takes much practice to master. Imagine my horror while sifting through the car’s endless manuals only to discover that there is no service book. It turns out that it’s all online now. I’m not sure I’m ready to put my service stamp into retirement just yet.
        
    Alas, the Audi will be returning to the workshop in the next couple of days. Sadly, I won’t need any tools to finish its service – just a computer.



  • Keep cool as air con heats up 

    As we move towards through summer, motorists are dropping the dial across the spectrum on their climate control systems.
        
    According to Adam White, Workshop Solutions Director at Euro Car Parts, repairers can make the most of the opportunity if they are properly equipped: “The key to profitability is offering the right services and performing them efficiently, in terms of both time and cost. By those measures, air conditioning is one of the most profitable service areas a workshop can be involved in – given the right expertise and equipment. Unfortunately, air con work is sometimes overlooked by garages who fail to see the potential profits it could bring to their business. With summer here, there are lucrative opportunities for those who are prepared.
      
    “Air con is a key growth area for UK garages. A lot of customers that visit a workshop have some form of issue with their air con system and the average job takes just five minutes. It’s easy to see why air conditioning remains one of the most profitable services that workshops can offer. If you want to make the most of the summer rush, now is the perfect time of year to invest in quality equipment.”
        
    As many workshops will know, automotive air conditioning systems use one of two specific gas types; either R134A or 1234YF. Adam observed: “Perhaps the most important decision for a workshop is whether to use a dual gas or double single gas setup. This will likely be dictated by the size of the business or the amount of air con servicing undertaken. The primary advantage of a dual gas machine is that you only require one unit to cater for both R134A and 1234YF, meaning less occupied space and reduce costs. The alternative is two separate machines, one for each gas. Having two machines is more expensive but it allows you to service two vehicles at once and offers greater opportunity for revenue-generation.
      
    “Workshops should ideally have the capability to cover both 1234yf and R134a systems. We aim to support the independent aftermarket in any way we can. Our latest Workshop Solutions brochure outlines the profitability of air con servicing and is well worth a read. New machines only require a hands-on time of around five minutes, with the total air-con service time taking between 45 minutes to an hour. This effectively gives you an additional pair of hands in the workshop – an hour of labour that can be used and charged elsewhere.”
        
    Adam continued: “Autoclimate’s products cover most of the UK market and it offers a support service that can fix 72% of the issues workshops encounter over the phone, minimising downtime. For the remaining problems, the company has 18 dedicated air con repair specialists committed to performing on-site repairs within three working days. For peace-of-mind, all its air con machines are eligible for a five-year warranty package with included annual servicing.”
        
    Adam concluded: “Whether you are considering investing in your workshop’s first air con machine or a seasoned veteran looking to upgrade, make sure that you evaluate the market to find one that best suits your requirements. The Workshop Solutions brochure is a great source of information and advice on how to maximise workshop profitability. The latest issue provides interesting insights into air-conditioning, including comparisons of popular models and useful finance examples.”

  • Hybrid theory 

    A chance to share your opinions, they said. Write an article if you feel so strongly about it, they said. Why did I choose one of the biggest titles in the automotive industry to write it for? Aim high, they said. How do I get myself into these situations? By taking the bait, they said.
        
    Writing is not my main occupation. I’m a tech like you. So, if you're reading this at work, in the time it took me to write that first paragraph, you have probably already carried out a full four-wheel alignment, or completed a MOT, or maybe got your hands on one of those hybrids, wearing your class 0 -1000v insulated gloves of course. Now I have your attention, you may have worked out that this article will be about hybrids. More to the point, whether or not technicians in workshops up and down the country are properly clued up on hybrids, or not as the case may be.
        
    The IMI are currently pursuing their idea for it to become mandatory to hold a hybrid qualification in order to service and repair hybrid vehicles. I believe this is the best way forward, not just because I already have my qualification, but simply because I believe it can save your life or a colleague’s life. At the very least, start by doing some sort of hybrid awareness course, especially if it's offered to you on a plate by your company.
        
    I would love one day to regularly have five or six EVs in our car park, with maybe a charging port out there too. In the meantime, I'll just have to make do with the one or two a week that roll ever so quietly into the workshop.

    Theoretical scenario
    I would like to run just a theoretical scenario by you... One day, in a small town that you won’t have heard of, a hybrid arrives at Bob’s Motors. The eponymous Bob eagerly awaits the arrival of his potential new customer, as does Fred, who is Bob’s chief mechanic, albeit more reluctantly. As Mr Smith walks into the reception, Fred's teabreak is mysteriously over and he slopes off. If there is any chance of being asked a technical question about a hybrid, Fred always hides. Bob however can’t believe his luck. He's heard in the pub you can charge whatever you want for working on these vehicles! Mr Smith wants a service on his car, and Bob prices the smart-dressed-man at £399, a random figure he plucked from nowhere. Mr Smith is over the moon as he was quoted a few more quid from his main dealer. The following day Fred walks into work. His first job is to service that stunning battery-powered machine that came in for a price on a service the previous day. With a big lump in his throat he cautiously takes the key from Bob, and then simply hands them back, exclaiming "I don’t know what I’m doing with this Bob, I've heard the can kill you if you don’t know what you’re doing."
        
    Bob’s reply: "You'll be ok, just don’t touch the thick bright orange cables.” Ok, I’ll stop this little story here as I couldn’t think of an ending that wasn't too graphic.

    Effort
    After speaking to a few good lads in the industry, what I find is that many are still scared at the thought of working on them. Fair enough if you haven’t had any relevant training on the subject, you may be worried. However, if make the effort to learn about hybrid and electric vehicles you will prosper. After all they are the future, whether we like it or not. But what do I know? I just work with cars.

  • blueprint for technical success 

    Have you ever wondered why it is that some technicians have an aptitude for complex diagnosis? You know the type of tech I mean. They take the seemingly unfixable, dive headlong into diagnostic battle and emerge triumphant time and time again.
        
    Not only that, but they’ll often do so in a time that makes other techs look on in awe! What’s their secret? And more importantly, can you emulate their success? Well, I’ve got some great news for you. You can, and knowing what to do is easy.  All that’s required is that you look to the past. History is a great teacher.
        
    I turned 50 this year, and one of the few benefits of increasing age is the ability to spot patterns, and patterns of actions that when followed culminate in your success. Patterns for success surround us, but sometimes you can be a little too caught up in the urgency of the now to spot them.
        
    I’ll show you the patterns great technicians use to triumph in the world of technical diagnosis, and how you can do the same. It’ll be your blueprint for success.
        
    You’ll like the blueprint. You’ll appreciate its simplicity, recognise the logic, and in all probability nod along as you read, agreeing with the steps that need to be followed.
        
    Here’s the deal though: You’ll need to implement it. Knowing the blueprint is easy, but knowing what to do doesn’t get the job done. It’s all in the implementation, and that starts with you taking small steps to achieve positive changes each day. Don’t forget one of my favourite sayings: “Progress NOT perfection.”
        
    I’m as much a fan of the latest technical gadget as the next man. I also love “cool” test techniques, but I’ve noticed that myopic focus on these can often be to the detriment of the long-term technical success of a technician. I’m not saying that you shouldn’t explore “shiny” elements in our craft, but you’ll find huge benefits in building a solid foundation that can be executed on every diagnosis. What do you need to “do well” then? Just these five steps.

    Step one – Systemise to win
    There’s always a right and not so right way to attack any given fault. One fundamental element is to have a defined system that all technicians use.  Without a rigorous system to follow, your diagnosis could be doomed before you start. Here’s an outline of our diagnostic system that just works;

    1 – Thorough questioning of customer, establish change point
    2 – Confirm and experience fault with customer
    3 – Visual inspection for obvious issues
    4 – Retreive fault codes, and gather data on what’s required to raise them
    5 – Inspect serial data. Note what looks wrong
    6 – Research technical bulletins and any technical information required for accurate testing.
    7 – Document what’s wrong and possible causes
    8 – Form plan and prioritise relevant tests
    9 – Carry out tests and draw conclusions
    10 – Bypass test to prove the conclusion where applicable
    11 – Repair as required.
    12 – Carry out postfix operations i.e. component coding.
    13 – Carry out tests to confirm repair

    Use our process and you’ll definitely be putting your best foot forward.

    Step two – Sound electrical knowledge
    Now you know what a great process looks like the next part of your blueprint is your understanding of automotive electrics. How quickly you can decide what to test, what tool to use, and what the answer should be is an essential skill that pays huge dividends once learnt. Key elements include:

    1 – Becoming comfortable with relationship between volts, amps and ohms
    2 – Using voltage drop to accurately find circuit faults
    3 – Series and parallel circuit diagnosis
    4 – Interpretation and use of wiring diagrams
    5 – Fundamental mechantronics test knowledge

    Armed with these, you’ll be able to find wiring faults, diagnose sensor and actuator circuits as well as build entry-level bypass tests to confirm your theories. These are skills you’ll use on the majority of diagnostic repairs. Learn these and you’ll reap the rewards for your entire career.

    Step three – Oscilloscopes; One tool to rule them all
    A little dramatic I know, but understanding how to use an oscilloscope competently is a game changer. It will bring to life all that has been learned in Step two (auto electrics), and when used skilfully will display this in a way that can confirm or deny faults in vehicle circuits, sensors and actuators.
        
    As an example, take just one quick connection (less than a minute on most petrol cars) to the switched side of a manifold injector and you’ll know;

    1 – That power supply to the injector is not open circuit
    2 – The ECU has control of the injector and is commanding fuel delivery
    3 – Time taken for fuel delivery to commence (injector opening)
    4 – Integrity of injector ground circuit
    5 – Time takes for fuel delivery to cease (injector closing)

    Add some additional test points for injector power supply, current and rail pressure (another couple of minutes) and you’ll confirm the integrity of the positive supply to the injector, the injector winding, and a great test for a quick look to ensure the injector is delivering fuel once open. Like I said - It really is one tool to rule them all!

    Step four - Generic systems knowledge
    With steps one through three in place you’ll now have the foundation knowledge to explore vehicle systems. This can be a little intimidating as there are so many systems and so much to see, which is why we advise attacking this in bite-size chunks. Your goal here is to become familiar with generic items that broadly apply to a wide cross-section of vehicles. While there’s no substitute for formal training, taking a few minutes on a regular basis to self teach is invaluable. Here’s some things for you to try:

    1 – Pick one system to start with. E.g. petrol engine management
    2 – Select a book or watch a video for some foundation learning
    3 – Focus on one part of a system. E.g. Loads sensors
    4 – Inspect serial data for MAF and MAP sensors across various load and speed ranges
    5 – Scope MAF and MAP sensors across load and speed ranges
    6 – Record your results and repeat on different vehicles on the same components
    7 – Repeat points one through six on different components

    Do this on a range of vehicles and systems and you’ll become incredibly familiar with what good looks like, as well as raising many questions that we’ll answer when you attend our training.

    Step five – Manufacturer information and tooling
    There’s one final piece to this part of the puzzle and that’s using the using the best information and serial tools.
        
    While I understand that generic information and tooling has its place, I also have too many real-world examples where my blood pressure would have been dramatically raised were it not for O.E. information and diagnostic tooling. My advice here is straightforward;

    1 – Select one manufacturer initially
    2 – Become intimately familiar with their information system
    3 – Learn to use their wiring diagrams
    4 – Explore their technical service bulletins
    5 – Use their repair procedures
    6 – Substitute a generic serial tool for the O.E. tool for a month
    7 – Explore all the serial tool has to offer

    We’ve been training technicians like you to use this equipment for many years. It’s had too much of an impact for those that have grasped the nettle for you not to give it a go.
        
    You now know what it takes to begin the road to technical success. All you need to do is start. Taking regular steps, and before you know it you’ll have not only reduced your stress but your time to a first time fix as well.


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