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Discussion Starter · #1 ·
After reading some threads on here and taking my Brera today for a forced Regen, I would like to possibly dispel some myths and inform others of my experience.
As soon as Chris plugged in his machine to force a Regen, keeping in mind we had discussed prior, the requirement to take it for a drive keeping it at a certain rpm, driving in a lower gear until the Regen had completed etc etc.....
As soon as he triggered the forced Regen, the car automatically increased the rpm to around 3500rpm, she sat there then happily cooking away as we watched the Regen process count down - No driving involved, no requirement to sit holding the throttle, the car basically did it all automatically.
Now, I have previously had a remap & an EGR delete so I am unsure if this has had an affect but reality is - A forced Regen will be carried out with no intervention or silly driving in low gears to do so, it will do it itself as soon as it's triggered.
 

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A forced regen using diag equipment is as you have described but when people talk of taking the car for a hard drive and keeping the revs up that is just to give the car the ideal conditions for it to do its own regen which is better for it, I think there is a limit to the number of diag forced regens the car will do.
 

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Discussion Starter · #3 ·
A forced regen using diag equipment is as you have described but when people talk of taking the car for a hard drive and keeping the revs up that is just to give the car the ideal conditions for it to do its own regen which is better for it, I think there is a limit to the number of diag forced regens the car will do.
Correct me if I am wrong or be given the wrong info, I am told from a mechanic at an Alfa dealership that there is no reason why you can't carry out a forced Regen every time you service the car, in his opinion it would take care of the dpf as a service item and more people should consider this during an annual service?
I only forced mine due to the fact that I've had a fair bit of work done to her in the last couple of months, the only item I had not seen to was the dpf filter. To make sure everything was clear, I opted for a forced Regen rather than the forced 'driving' method.
 

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during regens the car looks for 'ideal' circumstances, coolant temp, exhaust temp, soot fill levels of DPF, status of MIL etc etc. everything has to be within limits for it to happen

a forced regen is exactly that, your forcing the car to do a regen creating the ideal circumstances, via the diag equipment, for the process to be carried out.

a passive/active regens (when the vehicle decides to do it on its own) are, in reality a little harder to achieve, believe me... 2 years in a Commercial Merc dealer taught me this. Exhaust temps fluctuate widely when driving and its quite difficult to get this particular requirement into the window the ECU wants to see for long enough for the regen process to activate. In a perfect world you want a BIIIG hill and to be doing 50-60mph in 5th on cruise control untill the process activates then you dont really want to be braking or changing gear too often throughout its cycle, because it will result in a failed regen. ive known regens to activate after 2-3 minutes but have also known them not to activate after +45minutes of sufficient driving.

Found this lil bit of info from a different forum that outlines it quite nicely, yes... its VAG related... but its all the same regardless of which manufacturer deployed it. (DPF Regeneration Information - Must read for all drivers of DPF equipped cars - MkV (Mk5) Golf, Golf Plus & Jetta - uk-mkivs)

VAG DISESEL PARTICULATE FILTERS

Courtesy of David Bodily Volkswagen Technical Support Specialist

Diesel Particulate Filter (DPF)

Detailed below is important information outlining the function and features of the Diesel Particulate filter which all members of your team need to be aware of.

Diesel particulate filters are becoming more commonplace on diesel engines, particularly sizes 2.0L upwards. This is in order to reduce the exhaust emissions as required by European legislation.

The prime reason for a DPF is to reduce particulate matter entering the atmosphere. Particulate matter is found in the form of soot, which is produced during diesel combustion. The DPF traps most of the soot which would normally travel down the exhaust and into the atmosphere. The DPF can hold a certain amount of soot, but not a huge quantity and therefore it needs to go through a process called ‘regeneration’ in order to clear the soot loading. When the soot goes through a ‘regeneration’ process it will be converted to a much smaller amount of ash. The ash is non-removable. There are two types of ‘regeneration’, passive and active.

During long motorway journeys, passive regeneration will occur. This needs no intervention from the engine control unit. Due to the raised exhaust temperatures on a long journey (temperatures between 350 and 500°C), the procedure occurs slowly and continuously across the catalytic-coated (with platinum) DPF. The catalytic-coated DPF is situated close to the Engine, therefore the exhaust gas temperature is high enough (500°C) to ignite the soot particles. Due to this soot is burned-off and is converted into a smaller amount of ash.

Active ‘regeneration’ is when the ECU intervenes when the soot loading in the DPF is calculated to be 45%. The procedure lasts for about 5 – 10 minutes. Specific measures are taken by the ECU to raise the engine exhaust temperature to above 600°C, these include switching off the exhaust gas recirculation and increasing the fuel injection period to include a small injection after the main injection. The soot particles are oxidised at this temperature.

The ECU will trigger a regeneration process, if for some reason this is aborted, ie. customer slows down, stops etc, the process will be resumed when regeneration conditions are once again met, above 60km/h (38mph). This will continue for 15 minutes.

If after 2 attempts of 15 minutes, a successful regeneration has not been possible, the loading will increase. At 50% soot loading, the ECU will continue to maintain maximum exhaust temperatures of 600°C to 650°C to cause a regeneration process. The system will try to run a regeneration process for 15 minutes. If unsuccessful, the system will repeat this process for a further 15 minutes, if still unsuccessful, the DPF light on the driver display panel will then be lit.

The owners handbook states, the DPF symbol lights up to indicate that the diesel particulate filter has become obstructed with soot due to frequent short trips. When the warning lamp comes on, the driver should drive at a constant speed of at least 60 km/h for about 10 minutes. As a result of the increase in temperature the soot in the filter will be burned off. If the DPF symbol does not go out, the driver should contact an authorised Volkswagen repairer and have the fault rectified.

At 55% soot loading the DPF light is lit on driver display panel. At this point the customer should follow the advice in the handbook. If they ignore this information and continue driving the vehicle until the soot loading reaches 75% without successful regeneration, additional warning lamps will light up. At this point the customer will also be complaining of lack of power, etc.

At 75%, regeneration is still possible with the use of the VAS tester. Only when the loading is above 95%, is it necessary to replace the DPF unit.

Operating Status System Response

45% DPF Load Level 1
Normal Regeneration

50% DPF Load Level 2
Regeneration at maximum exhaust temperatures

55% DPF Load DPF lamp
Regeneration from 60 km/h onwards
("See operating manual")

75% DPF Load DPF, SYS and MI lamp
Torque limitation, EGR deactivation,

Regeneration via VAG tester only
95% DPF Load Replace the DPF Unit

The Warranty department has confirmed that if there is no fault on the vehicle and DPF regeneration has been unsuccessful due to the customers driving style and the customers failure to comply with the instructions in the handbook, DPF replacement will not be paid for by warranty.

Common causes for complaint

• Frequent short journeys – Regeneration conditions are not met.
Not recommended for sale in the Channel Islands and inner city driving.

• Customers who continue to drive the vehicle with DPF light on – Continued
driving with the DPF light on and without successful regeneration results in
excessive soot loading of the DPF, to a point where it is above 95% loaded.
At this point regeneration is not an option and replacement of the DPF is
necessary.

• Fault 18434 particle filter bank 1 malfunction – Common fault code. This does
not only relate to the DPF itself, but the entire exhaust gas handling system. This
can be caused by defective temperature sensors, pressure sensors, additive
system components (if applicable), poor connections, wiring issues, etc.

Important Information

• Before diagnosing a problem vehicle or attempting to perform an emergency
regeneration, it is important to obtain a full diagnostic log and read out relevant
measured value blocks. These MVB’s contain important information on the
condition of the DPF system and are essential in diagnosing the fault. When the
DPF light is illuminated, it does not necessarily mean that the DPF requires
regeneration. For further advice, please contact Technical Support with the
information from the diagnostic log and MVB data.

• If a problem vehicle arrives with the DPF light, the engine management light and
the emissions light on. If during your diagnosis and reading of relevant MVB’s,
you find that the soot loading exceeds 75% (but is still below 95%), an
emergency regeneration procedure must be performed with the VAS tester.
Further to this, the customer needs to be educated. They need to understand
why the lights have appeared on the dash panel. Their attention needs to be
brought to the owners handbook instructions, so that they are aware of what the
DPF light means and what to do when it appears. This should prevent
unnecessary repeat visits for regeneration purposes.

I have also found that as the car gets older 30K+ miles, you will notice that the regeneration takes place more often.

ALWAYS, check your oil before any long journey, as DPF regeneration can use a fair bit of oil.



Some questions and answers that may help;

Question: The glow plug symbol is flashing. Why? What should be done?


Answer: The DPF regeneration has not been completed during normal
driving and now DPF has reached its maximum saturation at which it can
still be regenerated. The limit value depends on variant and Model Year,
but is in the range of 105% - 125%.Possible causes for this are:


a.) Frequent short distance journeys, i.e. high soot loading while at
the same time regeneration of the DPF does not take place because the
conditions necessary were not fulfilled.

b.) Frequent
interrupted regenerations, i.e. the engine was switched off during
regeneration. Applies to short journey drivers who have at least
fulfilled the conditions for triggering regeneration. If the glow plug
light flashes, the vehicle

a.) Engine running since start for
longer than 2 minutes.
b.) Calculated saturation higher than 80%.

c.) Coolant temperature over 70°C for at least 2 minutes.
d.) No
DPF-relevant faults stored in system.
e.) A defined vehicle speed
threshold must have been exceeded (e.g. for >80% loading, 100 km/h)



Question: Under what conditions is regeneration
interrupted/ended once it has started?

Answer: Normally when
regeneration has been successfully completed, or:

a.) After a
maximum regeneration time (20 - 25 min.).
b.) If the engine is
switched off or has stalled.
c.) If the engine is left idling for a
long time (5 - 10 min.).
d.) If 1000°C is detected by the exhaust
temperature sensor.
e.) If during regeneration, a fault is detected
on the components relevant for combustion (injection/intake system).

If
a regeneration is interrupted once started but before it has been 50%
completed, the glow plug lamp flashes on the next engine start (cold or
hot) and regeneration begins again once the operating conditions (see 3)
have been fulfilled.

Question: How long does complete
regeneration take? a.) In the most favourable case? b.) In the least
favourable case?

Answer: a.) Under constant conditions, i.e.
the exhaust temperature necessary for regeneration always lies above the
required value, for example during motorway/cross-country driving, the
average regeneration time is 10 minutes.

b.) Vehicle
conditions such as long down-hill descents, frequent driving in the
low-load range (city driving, idling) allow the exhaust temperature to
fall. If the conditions for triggering regeneration were fulfilled, the
active regeneration time can be extended up to 25 minutes (depending on
engine type). If complete regeneration is not possible within this
period, the regeneration will be interrupted.

Question:
How does regeneration affect the oil life?

Answer: On each
regeneration or attempted regeneration, a certain diesel fuel amount is
injected into the engine oil which reduces the oil life. If the "INSP"
light in the instrument cluster comes on, the engine oil is exhausted
and must be changed. Failure to do so could damage the engine.
 

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Multiecuscan has capability to do a forced regeneration. It will tell you state of the DPF i.e. level of clogging, how many Regensburg have been done and when it was last activated, and, you can run one from the software. It does it all automatically, bringing revs and temperature up to required levels and holding it there during regeneration. The only advice it gives you is not the carry out the procedure on dry grass to avoid setting it alight! Worked well on my 159 Q4 Sportwagon.

Sent from my XT1562 using Tapatalk
 

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there is no reason why you can't carry out a forced Regen every time you service the car, in his opinion it would take care of the dpf as a service item and more people should consider this during an annual service?
I disagree, the car regenerates when the filter is clogged, it can sense that with a differential pressure sensor. Your car already regenerates the DPF pretty often, mine does it in intervals ranging from 1300km up to 1700km.
If you force a regeneration without the need for one you are wearing the engine and oil for no reason and wasting fuel, the car will do it when it needs to.
 

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Discussion Starter · #8 ·
Mine managed 210 miles between its last regens :/
I understand the Regen process but I have not noticed mine do a normal Regen hence the forced.
It couldn't have been that bad as it only smoked for about 20 seconds and then cleared. I won't be doing another one as I don't think there's any need to but I will watch what it does going forward?
Do you always get the indicator on the dash, this is what I have not seen.
 

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Discussion Starter · #9 ·
I disagree, the car regenerates when the filter is clogged, it can sense that with a differential pressure sensor. Your car already regenerates the DPF pretty often, mine does it in intervals ranging from 1300km up to 1700km.
If you force a regeneration without the need for one you are wearing the engine and oil for no reason and wasting fuel, the car will do it when it needs to.
Hence doing it at service intervals when you can change the oil & filter!
 

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Mine managed 210 miles between its last regens :/
I understand the Regen process but I have not noticed mine do a normal Regen hence the forced.
It couldn't have been that bad as it only smoked for about 20 seconds and then cleared. I won't be doing another one as I don't think there's any need to but I will watch what it does going forward?
Do you always get the indicator on the dash, this is what I have not seen.
On mine the first thing I notice is the boost gauge acting different. When you normally let off the accelerator it slowly drops and hovers slightly above the bottom.
During a regen it drops like a stone and then sits right on the bottom of the gauge.
When you come to a stop and the car is idling it lifts back up a little off the bottom of the gauge.
Another thing you notice if you watch the economy gauge is that the mpg drops dramatically.
 

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After reading some threads on here and taking my Brera today for a forced Regen, I would like to possibly dispel some myths and inform others of my experience.
As soon as Chris plugged in his machine to force a Regen, keeping in mind we had discussed prior, the requirement to take it for a drive keeping it at a certain rpm, driving in a lower gear until the Regen had completed etc etc.....
As soon as he triggered the forced Regen, the car automatically increased the rpm to around 3500rpm, she sat there then happily cooking away as we watched the Regen process count down - No driving involved, no requirement to sit holding the throttle, the car basically did it all automatically.
Now, I have previously had a remap & an EGR delete so I am unsure if this has had an affect but reality is - A forced Regen will be carried out with no intervention or silly driving in low gears to do so, it will do it itself as soon as it's triggered.
Everything is correct and it is a not a mystery.
I think it is a matter of definition used. Any engine map or remap are not unique and it is needed to know what exactly engine ECU has been done with. Fact that you can still initiate forced regen means that dedicated map does not affect DPF. My view it is wrong since any extra power map would increase soot creature to block DPF require more regens needed forced one included.
 

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Discussion Starter · #12 ·
Everything is correct and it is a not a mystery.
I think it is a matter of definition used. Any engine map or remap are not unique and it is needed to know what exactly engine ECU has been done with. Fact that you can still initiate forced regen means that dedicated map does not affect DPF. My view it is wrong since any extra power map would increase soot creature to block DPF require more regens needed forced one included.
Hi,
I don't agree totally but I may be wrong? As the EGR has been deleted, exhaust fumes are not being recirculated and therefore inlet manifold does not get blocked with carbon deposits. In theory this should reduce the dpf blocking issue as the engine should run cleaner?
However, I also understand that as the EGR is deleted with no exhaust recirculating then all fumes and deposits go through the dpf without burning some of it in the cylinders under combustion??
My theory is, the engine has to be running cleaner via the inlet side & the dpf is capturing what it would/should do normally either way?
 

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Hence doing it at service intervals when you can change the oil & filter!
But my point is: why are you forcing the car to do it when it doesn't need it? You are wasting fuel, losing time and wearing the engine while cleaning a filter that is not clogged yet.

I understand the Regen process but I have not noticed mine do a normal Regen hence the forced.
You don't notice it, you don't lose power, you only notice that the instant fuel usage gets higher than normal and when you release the accelerator the boost needle plummets to 0 instead of slowly dropping and hovering above zero. You will miss most of them, it's on purpose, this way drivers won't lose time thinking about it. If you are curious, connect to the engine ECU with multiecuscan and it will have several parameters regarding the DPF, including the distance from the last regeneration and the average distance between the last 2 or 5 regenerations.


Hi,
I don't agree totally but I may be wrong? As the EGR has been deleted, exhaust fumes are not being recirculated and therefore inlet manifold does not get blocked with carbon deposits. In theory this should reduce the dpf blocking issue as the engine should run cleaner?
However, I also understand that as the EGR is deleted with no exhaust recirculating then all fumes and deposits go through the dpf without burning some of it in the cylinders under combustion??
My theory is, the engine has to be running cleaner via the inlet side & the dpf is capturing what it would/should do normally either way?
Your inlet manifold will be significantly cleaner, the exhaust will see a significant increase in NOx emissions, most people that do EGR deletes also do a remap that makes the engine run richer under heavy loads, that will probably create more soot. The usual advance in the injection timing from the remap will probably increase NOx. I didn't disable my EGR or DPF because the car runs fine and I don't mind cleaning the inlet manifold every 3 or 4 years if that means having a slightly cleaner exhaust. If you don't care about that stuff, have you considered removing the DPF and not worrying about it anymore?

Regarding not noticing when the car is in the middle of a regeneration, I've thought about connecting a microcontroller to the OBD port to query the ECU from time to time to see if it's regenerating and buzz when it is, this way I won't stop the car in the middle of a regeneration by distraction. I do have all the parts required lying around, so if I get around doing that I'll post it here in the forum in case someone wants to do something similar.
 

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I understand the Regen process but I have not noticed mine do a normal Regen hence the forced.
It couldn't have been that bad as it only smoked for about 20 seconds and then cleared. I won't be doing another one as I don't think there's any need to but I will watch what it does going forward?
Do you always get the indicator on the dash, this is what I have not seen.
No, after the fifth consecutive failed attempt, the light on the dash will come on.
 

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Hi, I don't agree totally but I may be wrong? As the EGR has been deleted, exhaust fumes are not being recirculated and therefore inlet manifold does not get blocked with carbon deposits. In theory this should reduce the dpf blocking issue as the engine should run cleaner?
Correct. Everything DPF missed stick in inlet manifold. But EGR creates much more problems for inlet than helps DPF to be cleaner. My joke is EGR is open at idling only make possible MOT officer to measure NOX in minimal way. It is a joke of course but reality is not far from since EGR are basically closed at any productive engine regime.

However, I also understand that as the EGR is deleted with no exhaust recirculating then all fumes and deposits go through the dpf without burning some of it in the cylinders under combustion??
My theory is, the engine has to be running cleaner via the inlet side & the dpf is capturing what it would/should do normally either way?
Correct. Deleted EGR means EGR is always ECU closed. If EGR device still left on a car it is needed to make sure EGR device is really mechanically closed ( could stuck open or partly open ). So if EGR is closed everything goes to DPF and if EGR stuck open or partly open some parts still reach engine. DPF ( if it has not been mapped ) would regen disregard EGR. BTW EGR is closed while any regen.

So my question now is what you don't agree ???... Everything you has written does not contradict mine.
 
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