Cleaning blocked VW DPF

[RobinGill]

I did a job today that seems to have done the trick but I have a feeling it's not fully done.

I'm be honest and say this is only the third time I've done anything dpf related so I'm a bit of a noob. Sorry I don't have perfect measurements as I was only just really finding them all today.

VW Passat 2010 with a 1.6 CR had been to the dealers who couldn't regen dpf or clear codes/light and quoted something like ?1800 for replacement, went to another mechanic who tried with a forced driving regen with a Snap on verus who failed and brought it in.

The soot reading was 51.7g - above the max regen value of 45g. I had been thinking about cleaning the dpf then initialising it and regening it if pressure difference over 20hpa but the mechanic who brought it in talked me into initialising the dpf to 0g then getting it regen once on the motorway - got to about 750?c and calculated soot dropped from about 25g to 0, then we turned around, restarted it and regened it again and it went from about 23 to 4. Didn't really notice much smoke behind us.

I warned him of risk of fire prior and he insisted it wouldn't happen. The exhaust got a little hotter than I thought it would but we didn't abort as it did instantly drop if pedal lifted.

Customer now happy with car although says it's not perfect. Turned it off and on again now customer says car better then ever (he's had it since 5500 miles). Didn't get to take a final set of readings as my laptop died shortly after second regen.

Why did I regen it twice - I think I fooled the ecu into thinking there was 0g then it got confused with readings at about 50g and averged it with theoretical values to end up at 25g. Therefore if it did burn 25g first time, there was another 25g still left.

However I noticed back pressure went down from about 45-50hpa to more like 35ish. I would have thought a cleaned dpf should have gone much lower but didn't want to risk doing any more regens due to the extremes involved.

Customer also mentioned he recently filled with his normal oil he got cheap and the bottle didn't look right which got me thinking about that as a possible cause.

So here's my questions:

What's the highest soot weight/loading you reckon is actually safe to regen?

What sort of exhaust temps indicates it's too hot and I should abort/grab a fire extinguisher?

Have I actually done much?

If I haven't really done anything:
When he comes back do we properly clean his dpf, initialise again then do one regen and blame it on the oil?
Is his car at risk of catching fire as the ecu doesn't know the real ash value?

[Meat-Head]

HUH sorry to late at night to read drivell

if you unsure about it catching fire - some Citroen dealer don't do them anymore a C5 caught fire

Scares the crap out of me to be honest.

take the DPF off he car fill with TRF traffic film remover and keep flushing it with a hose pipe (freezing weather?)

10 mins one way runs clear, turn over hose pipe 10 mins runs clear, keep doing that till your bored

make sure there are no fault codes - EGR valve for a start

Some guy basically does a million miles everyday down motorway his ALWAYS comes on dealers says redline everygear untill 15 mins/miles

he does this evry 3 months alwys sorts it.

HTH

Meat

[arvedo]

hello well explained but the vast majority fall back in a couple of months, you lose a lot of time cobras bit, it's best to remove fap and no more problem.

[genius76]

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 ***8216;regeneration***8217; in order to clear the soot loading. When the soot goes through a ***8216;regeneration***8217; process it will be converted to a much smaller amount of ash. The ash is non-removable. There are two types of ***8216;regeneration***8217;, 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 ***8216;regeneration***8217; is when the ECU intervenes when the soot loading in the DPF is calculated to be 45%. The procedure lasts for about 5 ***8211; 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

***8226; Frequent short journeys ***8211; Regeneration conditions are not met.
Not recommended for sale in the Channel Islands and inner city driving.

***8226; Customers who continue to drive the vehicle with DPF light on ***8211; 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.

***8226; Fault 18434 particle filter bank 1 malfunction ***8211; 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

***8226; 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***8217;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.

***8226; 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***8217;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.

[Meat-Head]

. 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 ***8216;regeneration***8217; in order to clear the soot loading. When the soot goes through a ***8216;regeneration***8217; process it will be converted to a much smaller amount of ash. The ash is non-removable. There are two types of ***8216;regeneration***8217;, passive and active.


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


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.


SUMMARY

Theres a bit of metal full of RARE metaerals under your car this saves the dirty diesel fumes to comply with EEC emmisions then uses MORE diesel and damages the oil - more envirmental damge as you go down the road.

Also a serious risk of fire cool.


Look on a popular auction site for dpf emulator think ?150 or something battery airflow and pressure sensor

[genius76]

SUMMARY

Theres a bit of metal full of RARE metaerals under your car this saves the dirty diesel fumes to comply with EEC emmisions then uses MORE diesel and damages the oil - more envirmental damge as you go down the road.

Also a serious risk of fire cool.

It was here that I totally agree with you:lollypop:

I'm just worried that it will start to do and in airplanes or ships:laugh:

You should see a lot of beautiful work with your TRF traffic film remover and a hose pipe - is not it?

[smirnoff_rules]

m8 of mine works for vw and they don't regen in the workshop now . they over fuel with the computer and drive for an hour , another m8 works for vauxhall and they had a letter says they
are going to stop putting them on cars made for the uk as we don't do the mileage here to keep them Clean

wot scanner u
using m8


Sent from my iPhone using Tapatalk

[RobinGill]

Thanks for all the replies.

I'm baffled why the vw dealer that saw it first couldn't do anything with it as they must have had vas.

I like the tfr idea - much cheaper then the tunap kit work paid for!

I did it with vcds as mentioned (surprised it did the job)

[1 6 D]

1.6/2.0 CR TDI have the same regeneration methods:
- while Standing/Idle
- while Driving

At first you have to enter the Code in Security Access:
-12233 = Adaptation Enabling (e.g. DPF/NOx Regeneration while Driving)
or
-27971 = Basic Settings Enabling (e.g. Regeneration while Standing)

Then if you want drive you have to go to adaptation channel, in my 2.0 it's channel 13 and enter new Value "1" to start regeneration.

If you want to regeneration while standing you have to go to basic settings. In my 2.0 it's channel 226.

Here is some info about regeneration too:
Diesel Particle Filter Emergency Regeneration - Ross-Tech Wiki (http://wiki.ross-tech.com/wiki/index.php/Diesel_Particle_Filter_Emergency_Regeneration#1.6l .2F2.0l_R4_CR-TDI)

[RobinGill]

Interesting - that page only mentions to enter the code given on screen - all I was given was 27971 which for me enabled regen while driving rather than static .

Was thinking about this further today and I'm thinking what I really should have done was when initalising the dpf to set the ash level to just below the max threshold then regen till the ecu says it's clean, then initialise it again and put back a touch more than I initally deducted.

Probably not as perfect a job as properly cleaning the dpf but quick easy money while still respecting the correct operation of the system so in a perverse way I'm thinking that may actually be less of a bodge.

[Desertstorm1]

You shouldn't be going much over 600 degrees c during a regen, DPF's are a bit like car batteries, If you look after them well they will last a long time. DPF's if they get very blocked will never completely clear. Quite often there are undiagnosed sensor issues that lead to the DPF's blocking up. I would get the car remapped and the DPF removed. Cheaper and better in the long term.

[smartymarti]

we dont get many in but have seen a leon cupra with 92% blocker everyone was telling him turbo etc, we put a new g450 sensor high preasure sensor and regenerated it never been back , nearly all the ones we have seen seem to be the 2.0 170 bhp engines all with failes g450 sensors, onlyt 1 2.7 we had to remove cat and reap etc, my point being as long as its not just the dpf and theres unlying issues you can do a regen at just about any percentage

[smokey08]

I done a saab 9-5 on friday that was 112% blocked, Blew some of the soot out with an airline then jet washed it out then sprayed loads of tfr in it and let it soak for an hour before jet washing it out again. Cleared the fault codes and drove it down the road to regen it. It smoked a bit when it started to regen then cleared. Checked it again with autocom when I got back to the workshop and it said soot content was 16%.

Dont forget to fix the problem that caused it to block up. This one was caused by a split intercooler pipe.

I use this procedure alot with excellent success rates.

[jnoroeste]

Hi M8's,

Understanding dpf sensor and wires are ok, the solution is clean de dpf.

Ultrasonic cleaners will do the job, easy and cheap compared with a new one. Remember recode as new dpf fiter installed to reset regens counter.

Another solution could be deleting dpf in ecu maps.

Regards.