My 3 Cents.
I was reading this whole thread for a while and have a few points to make. Seems to me that there is a lot of folklore in the subject. Don't want to step on any toes but there are some things I'd like to point out.
Read slowly!
DPFs are designed to filter out DPs (soot) from the diesel exhaust. They are designed as NOT "see trough" filters like catalytic converters are BUT have the small channels closed off so the exhaust gas (small molecules) CAN pass trough but DPs (big particles) cannot.
Now how big are we talking about. Well, the modern will filter out particles of 1 micron (1 millionth of a meter) and bigger with about 95% and higher efficiency! To compare, dust mite is about 300 microns, human hair is 20-180 microns, red blood cell 6-10 microns. You get the idea, what we are talking about here???
So, any idea of cleaning it by flushing it, especially in the direction of the exhaust, no, I'm not buying it
. Yes it is possible to clean the by blasting the DPs by highly compressed air in the direction opposite to the direction of exhaust, baking the in high temperature (around 800 C) overnight and finally, again blasting the remaining ash with highly compressed air and that is how this is really done professionally. Additionally, on 2.0T diesel the is combined with oxidation catalyst. So, to clean it properly you would have to cut the part out first.
Now, on the so called regeneration.
As you drive and the is filtering the soot out of the exhaust, the design of the exhaust (catalyst and close to exhaust manifold) is doing the regeneration by itself, without any input from . Simply put the CAT and get hot enough (around 600 C) for long enough for this process to take place. This is called
passive regeneration.
If the the above scenario does not happen, the is taking active role and starting so called
active regeneration. In which it will try to increase the temperature of the by injecting extra fuel, delaying injection, adding extra air and so on. This usually takes care of the problem, provided that the car is driven long enough.
If this is not the case and the soot level continues to increase, the will turn the warning lamp ON after the soot level crosses the threshold value (about 24 grams). This is to let the driver know to preform so called
regeneration drive on which the driver can read in his / her OWNERS MANUAL.
If the driver fails to do so and the soot level continues to increase, the glow plug and check engine indicator will light up as well, as soon as the soot level reaches 40 grams. This is to let the driver know that the active regeneration is turned off and only
service regeneration is now possible. This is done by following a special procedure with or other capable tool.
If the driver fails to do so and the soot level reaches 45 grams the regeneration is turned off and needs to be replaced with new or reconditioned one.
Additionally, as a safety measure, the will also start an active regeneration automatically if during the last 466 to 621 miles (750 to 1000 km) of travel no successful regeneration has taken place, regardless of soot level.
uses bunch of sensors (temperature, pressure, air flow, O2 content) and internal map to determine the soot level. Therefore, you have soot level calculated and measured in MVBs. This information is used (along with the sensor data) to start, conduct and finish active regeneration.
All this information can be red and, with a informed use of label file, evaluated in relevant MVBs with . So, you know what is really going on with your system.
So, now, after you red this, what do you think is going on with your car?
Can you start proper diagnose 1st, maybe, by posting the relevant values from the relevant MVBs ( related)?
Maybe, then we can learn something together and your car gets fixed in the process.
BR, Andy