Clean Diesel DPF Data Collection Thread

[umrpunter]

anyone want to start a full excel sheet of this? With enough data points we can do some simple stats on it to figure out what we can expect. All we need is data, and the density of soot (I believe it was said to be /1g/ml, but probably should double check).

[Elfnmagik]

MemberName: elfnmagik
Model Year: 2009
Model: Jetta, 4dr
Tranny: DSG
Miles: 51,700
Oil Ash Volume: 48ml
Avrg. MPG: 38 (lifetime)
No. of regens: 4.0
Current soot load: 16.5 (went into a regen right after)
Oil type: Mobile 1 ESP

[Absolute Diesel]

Was there a definitive answer on the max level of oil ash volume these filters can take or were we just guessing?

Is there a difference in this max level between the 09 DPF design and the 10+ DPF design?

[darrelld]

Originally Posted by Absolute Diesel

Was there a definitive answer on the max level of oil ash volume these filters can take or were we just guessing?

Is there a difference in this max level between the 09 DPF design and the 10+ DPF design?

I cannot find anything definitive from VW on ash levels, if you read the MIT study below the amounts seem to vary. The study does indicate a possible to solution to cleaning ash from a DPF by heating beyond 1000C, not certain what those temps will do to the VW specific design. Might be worth a shot if you are looking at replacement anyway and have the tools and facility to experiment.

[tcp_ip_dude]

This was previously mentioned, so it may not answer your question.

(Excerpted from the VW 2.0L CR self study guide.)

"When the DPF load condition reaches 1.59 ounces (45 grams), service regeneration is no longer possible. Because the danger of destroying the filter is too great with this load, the filter must be replaced."

[HeAvYfUeL]

MemberName: HeAvYfUeL
Model Year: 2009
Model: Jetta Wagon
Tranny: DSG
Miles: 24,250
Oil Ash Volume: 18 ml
Avrg. MPG: 35.1
Oil: Castrol LL03
Location: QC

Comments:
Sometimes use PS. Mainly only in the winter.
8.1 Soot Load(g) Calculated
0.0 Soot Load(g) Measured
1.4 l Fuel Consumption Since last Regen
20 km Mileage Since last Regen
24.0 Time elapsed since Regeneration

[Absolute Diesel]

Originally Posted by tcp_ip_dude

This was previously mentioned, so it may not answer's your question.

(Excerpted from the VW 2.0L CR self study guide.)

"When the DPF ash load reaches 1.59 ounces (45 grams), service regeneration is no longer possible. Because the danger of destroying the filter is too great with this load, the filter must be replaced."

Thanks for posting this - but something does not add up (or I am missing something).

If you convert 1.59 oz's to ml we get roughly 47 ml. There are posters with ash in the 40-60 range and they have not have to have their units replaced.

[WVU TDI]

Originally Posted by Absolute Diesel

Thanks for posting this - but something does not add up (or I am missing something).

If you convert 1.59 oz's to ml we get roughly 47 ml. There are posters with ash in the 40-60 range and they have not have to have their units replaced.

fluid oz =/= weighted ounces?

[JSWTDI09]

I fear we are confusing DPF oil ash load with DPF soot load. Ash load has very little to do with the ability to do a re-gen (unless the DPF is so full it prevents air flow). Soot load is what makes regeneration necessary and too much soot load might make regens impossible. However, ash load is the accumulation of ash that is the result of regeneration (not the cause).

What the Self study book actually says is: "when the load condition reaches 1.59 ounces (45 grams) service regeneration is no longer possible". It does NOT say "ash load" - they are talking about soot load. The soot is trapped in the DPF. When the DPF regenerates, that trapped soot is burned and the ash falls down to the bottom of the filter and accumulates in the bottom of the DPF canister. This is the "oil ash load".

Let's not confuse soot load with ash load - they are very different things. This subject is confusing enough without adding additional confusion about terms. Semantics (words) can easily blur understanding.

[edit] To summarize: "Soot load" is the cause of re-generations, and if regens cannot (do not) occur too much soot load can make regens impossible. However, "ash load" is the accumulated result of many regenerations. When the DPF gets so full of ash that exhaust gas flow is blocked - the DPF must be replaced (or serviced, hopefully). If everything is working properly - this should be well over 120k miles.

Have Fun!

Don

[darrelld]

Originally Posted by JSWTDI09

I fear we are confusing DPF oil ash load with DPF soot load. Ash load has very little to do with the ability to do a re-gen (unless the DPF is so full it prevents air flow). Soot load is what makes regeneration necessary and too much soot load might make regens impossible. However, ash load is the accumulation of ash that is the result of regeneration (not the cause).

What the Self study book actually says is: "when the load condition reaches 1.59 ounces (45 grams) service regeneration is no longer possible". It does NOT say "ash load" - they are talking about soot load. The soot is trapped in the DPF. When the DPF regenerates, that trapped soot is burned and the ash falls down to the bottom of the filter and accumulates in the bottom of the DPF canister. This is the "oil ash load".

Let's not confuse soot load with ash load - they are very different things. This subject is confusing enough without adding additional confusion about terms. Semantics (words) can easily blur understanding.

Have Fun!

Don

Anyone know the highest mileage 09 TDI and the status of the DPF?

[JSWTDI09]

Originally Posted by darrelld

Anyone know the highest mileage 09 TDI and the status of the DPF?

There are definitely some '09s with over 120k miles and still on the original DPF. I would love to see their ash load numbers, but they are not here.

Have Fun!

Don

[tcp_ip_dude]

Originally Posted by Absolute Diesel

Thanks for posting this - but something does not add up (or I am missing something).

If you convert 1.59 oz's to ml we get roughly 47 ml. There are posters with ash in the 40-60 range and they have not have to have their units replaced.

Different units of measure. What I posted are weights (ounces and grams) not volume (liters / fluid ounces). You cannot convert grams to liters.

[tcp_ip_dude]

Originally Posted by JSWTDI09

I fear we are confusing DPF oil ash load with DPF soot load. Ash load has very little to do with the ability to do a re-gen (unless the DPF is so full it prevents air flow). Soot load is what makes regeneration necessary and too much soot load might make regens impossible. However, ash load is the accumulation of ash that is the result of regeneration (not the cause).

What the Self study book actually says is: "when the load condition reaches 1.59 ounces (45 grams) service regeneration is no longer possible". It does NOT say "ash load" - they are talking about soot load. The soot is trapped in the DPF. When the DPF regenerates, that trapped soot is burned and the ash falls down to the bottom of the filter and accumulates in the bottom of the DPF canister. This is the "oil ash load".

Let's not confuse soot load with ash load - they are very different things. This subject is confusing enough without adding additional confusion about terms. Semantics (words) can easily blur understanding.

[edit] To summarize: "Soot load" is the cause of re-generations, and if regens cannot (do not) occur too much soot load can make regens impossible. However, "ash load" is the accumulated result of many regenerations. When the DPF gets so full of ash that exhaust gas flow is blocked - the DPF must be replaced (or serviced, hopefully). If everything is working properly - this should be well over 120k miles.

Have Fun!

Don

Don is right on this, it does say "load condition" and I think the distinction he makes between "ash" and "soot" is very important. My bad. Good catch and good point. Thanks Don.

I made a mistake when I transcribed the wording from the self study guide (couldn't easily cut and paste from the guide using my iPad). Corrected wording in original post and annotated reason for correction.

[Plus 3 Golfer]

The problem we have is that we do not know the actual density of the soot or ash in the DPF. One can convert grams to liters and liters to grams, if one knows the density of the soot or the density of the ash in the DPF. I have read a study that said the range of diesel soot density is between 0.6 - 1.0 g/ml. The range is because the porosity of the soot can vary. I can not find any range for density of ash in a DPF.

It would be great if we had access to the algorithm used to make estimations of soot and ash load. The soot / ash loads are likely estimated / calculated over time based on pressure drop across the DPF, air flow (MAF data), fuel consumption, and perhaps other data. We can assume that the algorithm makes assumptions in order to compute how much soot has been oxidized and how much ash has accumulated during active / distance / service regens. As the DPF fills with ash over time, the minimum measured differential pressure drop should gradually increase (more permanent blockage of the air path through the DPF by ash). It makes sense to measure permanent "blockage" by volume and not grams as the density of ash can vary.

The MIT study indicates that the typical porosity of ash is 85-95% and if the exahust temperature of the DPF is over 700*C, there is a large reduction in the volume of ash. Thus, there is the potential to reduce ash volume considerably at very high exhaust temperatures.

It seems all we can do now is to collect the DPF data as miles on our cars accumulate and DPF replacements /cleanings are required. With enough data and replacements / cleanings we might be able to draw some conclusions on the expected life of the DPF based on the data.

[dweisel]

Originally Posted by JSWTDI09

I fear we are confusing DPF oil ash load with DPF soot load. Ash load has very little to do with the ability to do a re-gen (unless the DPF is so full it prevents air flow). Soot load is what makes regeneration necessary and too much soot load might make regens impossible. However, ash load is the accumulation of ash that is the result of regeneration (not the cause).

The soot is trapped in the DPF. When the DPF regenerates, that trapped soot is burned and the ash falls down to the bottom of the filter and accumulates in the bottom of the DPF canister. This is the "oil ash load".


Have Fun!

Don

From the looks of it there is no area at the bottom of the DPF for ash to accumulate. Looks like the ash just builds up in the DPF tubes. Unless the US version is designed different,I would think ash would build the same.

Here is some interesting reading and pics.
http://www.myturbodiesel.com/forum/f...ssection-8267/