I only have a working theory of when the Oil Ash is high, and near "end of life" it will increase the regenerations (not due to soot!) just a time/distance one.

My own car put on exhaust light just last week, I was home in 5 minutes, and scanned low Soot (both measured and calculated!)

 

So if you tell car it has new DPF, then it should stop these weird regenerations that are not due to too much soot.

 

I am happy to test this, as I don't care about the "trouble" and then I can trust the soot measurements to decide when to regen.

More crazy units from VCDS, kms since last regen 21m, WTF is that supposed to be, minutes? Kms? Metres?

 

If the 660 seconds time since last regen is to be believed (and I am not confident about any of the units) then 21kms in 11 minutes is implausible unless you are on the autoroute. Could it be 21 metres shufling around on your driveway with the engine ticking over for 11 minutes?

 

In any case 5.58 grammes measured of soot (or the backpressure that they believe equates to that) is not good at all, you will know the journey that you have just taken either it had not fully completed a regen and got down to the 3 gramme (I think) threshold because you stopped or because the thing is so choked the sensor is always reporting back pressure equating to 5 grammes.

 

I dont think telling it you have a new DPF is going to change anything if your measured soot level either goes up that quickly or cannot come dow enough during a regen.

 

You must be using a hell of a lot of fuel surely?

1 hour ago, Orman said:

But how come the car starts to actively regen with only 5,58g of measured soot, exactly every time I go out and drive? On longer drives, even on straight highways, it will even pop up with a check DPF warning.

 

On 11/11/2022 at 20:54, J.R. said:

To answer your question, and this is only speculation on my part, its trying to do a regen all the time because it hasn't been able to complete the previous ones, 8.71/5.58 grammes is probably above the regen completed threshold, you will find what it is amongst the millions of VCDS measuring blocks, 3 grammes rings a bell for my engine.

 

20 minutes ago, J.R. said:

More crazy units from VCDS, kms since last regen 21m, WTF is that supposed to be, minutes? Kms? Metres?

 

If the 660 seconds time since last regen is to be believed (and I am not confident about any of the units) then 21kms in 11 minutes is implausible unless you are on the autoroute. Could it be 21 metres shufling around on your driveway with the engine ticking over for 11 minutes?

 

In any case 5.58 grammes measured of soot (or the backpressure that they believe equates to that) is not good at all, you will know the journey that you have just taken either it had not fully completed a regen and got down to the 3 gramme (I think) threshold because you stopped or because the thing is so choked the sensor is always reporting back pressure equating to 5 grammes.

 

I dont think telling it you have a new DPF is going to change anything if your measured soot level either goes up that quickly or cannot come dow enough during a regen.

 

You must be using a hell of a lot of fuel surely?

Yea I was shuffling it around the drive away when that picture was taken. Yea… it’s drinking fuel like nothing else. Is there any possible way to save this DPF? Will any of those DPF cleaning additives help? Cause replacing it is not even an option since it’s very expensive, id rather have the DPF gutted and deleted instead. But that is also undesirable, since I’d like to keep it as stock as possible. 

There are two values I have read in the documents, one states that it stops active regen at 10%, and the other states 15% (the two values could represent CR and then PD engines)

What they don't state is what the scale is, now 45g of soot is the game over point, so 10% could mean 4.5g.

 

As @J.R. mentions, if the car was doing an active regen and you turn it off during, then should carry on next time you start.

They also do have 1,000km so called "self-test" but they don't mention if this decreases with age.

10 hours ago, varooom said:

There are two values I have read in the documents, one states that it stops active regen at 10%, and the other states 15% (the two values could represent CR and then PD engines)

What they don't state is what the scale is, now 45g of soot is the game over point, so 10% could mean 4.5g.

 

As @J.R. mentions, if the car was doing an active regen and you turn it off during, then should carry on next time you start.

They also do have 1,000km so called "self-test" but they don't mention if this decreases with age.

Also, if I try to do a forced regen with VCDS when standing still, it will abort after a couple minutes. No fault codes just says “aborted”. Any idea why?

Surely driving for 2,5 hours (180 km) non-stop at freeway speeds, then turning around and driving the same back home after a quick stop at McDonald’s would be enough to finish the regen? When I arrived home and parked it, I noticed idle rpm at 1k and smell of soot. On the way back home I even drove almost completely in 4th gear at 2500-3000 rpm and a lot of WOT for this reason. It seems to me it just never finishes the regenerations no matter how long or hard I drive it.

The value of your oil ash volume is just an estimation, if your car uses more than average amount of oil, then the exhaust will perhaps already be full.

 

The DPF regen process can abort if parameters are out of spec, though the software/car may not specify a reason, did you notice any strange values during forced regen?  Temperature too low/high, was the soot levels reading ok, or negative values, was fuel level enough or had it dropped low?

 

As for your long motorway trip, it should have cleared the DPF in that distance, but again it depends on health of exhaust, and as mentioned, you cannot rely on the figures the car presents, they are just estimations of the oil ash.

Just now, varooom said:

The value of your oil ash volume is just an estimation, if your car uses more than average amount of oil, then the exhaust will perhaps already be full.

 

The DPF regen process can abort if parameters are out of spec, though the software/car may not specify a reason, did you notice any strange values during forced regen?  Temperature too low/high, was the soot levels reading ok, or negative values, was fuel level enough or had it dropped low?

 

As for your long motorway trip, it should have cleared the DPF in that distance, but again it depends on health of exhaust, and as mentioned, you cannot rely on the figures the car presents, they are just estimations of the oil ash.

VCDS won’t even trigger the regen, it won’t even elevate the rpm and exhaust temps stay at 163 degrees, then it suddenly aborts after a while. The Autocom will actually initiate a forced regen, and rpm go up to 1500 and DPF temps increases. But after 30-40 minutes it also aborts, and DPF temp only reaches a maximum of around 588 degrees with all power consumers on. It should be over 600 degrees if I’m not mistaken.

2 hours ago, Orman said:

Surely driving for 2,5 hours (180 km) non-stop at freeway speeds, then turning around and driving the same back home after a quick stop at McDonald’s would be enough to finish the regen?

I think you are confusing what a regeneration is (burning off as much soot as can be done) with how the soot values are measured (which they aint) or calculated which is pretty much fantasy and completely skewed after the emissions fix.

 

The ECU does not know that you now only have 3 grammes of soot left so it can halt the regeneration, it is relying on the pressure drop measured across the DPF and what would correlate to 3 grammes of soot in an otherwise healthy and unblocked DPF oil ash residue throws this off and a near end of life DPF like yours will be partially blocked by oil ash residue and the pressure drop will never be low enough for the ECU to consider that the regen has completed.

 

Have you checked your engine oil level? From what you have described I would expect a very high oil level with it being diluted by diesel.

 

I have no idea if any of the treatments or cleaning services will actually help you, it may sound like I know a lot about DPF's but it's only through realising a year or so back that I was driving a ticking financial time bomb and being concerned by the over frequent regens that I started researching the subject and taking steps to mitigate against ending up where you are.

2 hours ago, varooom said:

The value of your oil ash volume is just an estimation, if your car uses more than average amount of oil, then the exhaust will perhaps already be full.

 

Also if a non Low Saps oil has been used in the past, does the OP know the service history of his vehicle? Even with it a garage could be charging a premium for low Saps oil but refilling with a cheaper fleet grade oil.

13 hours ago, varooom said:

They also do have 1,000km so called "self-test"

 

Thats interesting, one time I heard the fans running so plugged in VCDS and it showed an exact figure of 1000kms (might have been 500kms) plus the distance driven during the regen, it seemed to exact to have been a coincidence.

 

Maybe mine is not regenning more frequently than the measured values would require and its the self test at 1000kms or maybe 500kms. I will have to keep connecting and making a log once again of the readings, its so rare now that I hear or feel a regen happening which can only be a good thing, the measured soot values are reassuringly low.

 

I believe that the big difference between my now rolled back ECU software and the previous Emission Fix one is that regens now only happen when the measured soot value exceeds the limit and not when the calculated ones do, the self test aside.

 

I have fitted an ECU emulator, I could see that it was definitely reducing the build up of soot but the regens triggered anyway from the calculated value, the rollback has stopped that aside from the anomoly of the 1000km (maybe) 500km regen when I saw that the soot level was nowhere near high enough to generate one.

 

I guess its there as a guard against someone removing the DPF core, if when it does a regen it does not see the pressure drop reduce in the way that it should perhaps it creates a fault code and MIL light? Also in the case that an oil ash blocked DPF does not reduce correctly?

Some values and information that could be useful to our subject.

 

Once the load threshold of the diesel particulate filter has been reached, the exhaust gas temperature is lowered by the engine management system.  
This is necessary because the particulates accumulating oxidise into carbon dioxide  
in a temperature range between 600 and 650 °C.
(For diesel fuels covered by DIN EN 590, the combustion of particles is possible at a lower temperature, at approx. 500 - 550 °C, as the fuel contains additives.  
These additives reduce the required temperature for burning the soot).

 

So better quality diesel will have a lower burn temperature.

 

 

Here is the image for the 1,000km self-test that doesn't bother about measured values

16 hours ago, varooom said:

Some values and information that could be useful to our subject.

 

Once the load threshold of the diesel particulate filter has been reached, the exhaust gas temperature is lowered by the engine management system.  
This is necessary because the particulates accumulating oxidise into carbon dioxide  
in a temperature range between 600 and 650 °C.
(For diesel fuels covered by DIN EN 590, the combustion of particles is possible at a lower temperature, at approx. 500 - 550 °C, as the fuel contains additives.  
These additives reduce the required temperature for burning the soot).

 

So better quality diesel will have a lower burn temperature.

 

 

Here is the image for the 1,000km self-test that doesn't bother about measured values

Do you know how the DPF is located on these cars? Is it difficult to get to, and is it welded in the exhaust or held on by clamps? I might just replace it and save myself some headache.

3 hours ago, Orman said:

Do you know how the DPF is located on these cars? Is it difficult to get to, and is it welded in the exhaust or held on by clamps? I might just replace it and save myself some headache.

I don't know exactly where yours is located, odds are behind engine and not under the car.  I am 99% sure they are clamped on, but you may wish to check on prices as they will make your eyes water.

Just now, varooom said:

I don't know exactly where yours is located, odds are behind engine and not under the car.  I am 99% sure they are clamped on, but you may wish to check on prices as they will make your eyes water.

I found a brand new aftermarket one for $400. If not, I’ll just remove and clean it out myself or have it sent off to be professionally cleaned.
 

However I have booked an appointment at a VAG/Skoda dealer for proper diagnosis. They are gonna take a look and see if the DPF is actually blocked, or if the issue is somewhere else. If not, they are gonna try a forced regen, which I was not able to do successfully with either VCDS or Autocom.

I am shocked it is that cheap considering it supposed to have Platinum inside!

 

It's a pity you have booked the car in with dealer's, they will gladly take your money and you won't be any better off.

 

If you have no fault codes in engine, and soot is under 45g, oil ash below threshold, that means exhaust is healthy.  The only possible fail is if the live readings are not sensible/logical.

 

Edit: I should clarify by healthy I mean that it's within parameters, doesn't mean it's as efficient as when new.

Edited 14 November, 20223 yr by varooom

2 minutes ago, varooom said:

If you have no fault codes in engine, and soot is under 45g, oil ash below threshold, that means exhaust is healthy

... according to the diagnostics, but as some of those 'calculations' are not based on measured data but estimated the values may not reflect reality especially if there have been other sources of soot/ash i.e. engine oil.

12 minutes ago, PetrolDave said:

... according to the diagnostics, but as some of those 'calculations' are not based on measured data but estimated the values may not reflect reality especially if there have been other sources of soot/ash i.e. engine oil.

Yes there was the guy whose car was drinking 6l of oil per 15,000km, no way the oil ash values in his car were correct.

 

I am not sure if the calculation soot is above 45g it can block a regen, measured 100% would do.  That could indicate a broken DPF sensor (had this happen to me)

38 minutes ago, varooom said:

I am shocked it is that cheap considering it supposed to have Platinum inside!

 

It's a pity you have booked the car in with dealer's, they will gladly take your money and you won't be any better off.

 

If you have no fault codes in engine, and soot is under 45g, oil ash below threshold, that means exhaust is healthy.  The only possible fail is if the live readings are not sensible/logical.

 

Edit: I should clarify by healthy I mean that it's within parameters, doesn't mean it's as efficient as when new.

Soot mass calculated: 2,44g

soot mass measured: 5.58g

Oil ash mass: 69g

Oil ash limit: 80g

 

These are the readings I pulled from VCDS. I guess oil ash is near the limit, and that’s why it’s regenerating all the time to try and reduce it, but my understanding is that oil ash can’t be burnt off, and because of that it never finishes the regen no matter how long I drive, because it’s not able to reduce the amount of ash.

 

Like you said, I could probably trick it by resetting the DPF values to zero and that could solve the constant regens for now. But in the future if the oil mash reaches the 80g limit and the DPF is completely blocked, I don’t know if the car will be able to tell, since all the values has been reset. And driving like that without knowing will probably hurt the turbo/engine because of all that backpressure.

 

I’ll post two pictures. One is how the DPF looks like, and the other is the cheap aftermarket replacement. It seems there are two units, I don’t know what the other smaller one is, a dosing unit? No idea. The cheap replacement looks to be only the filter itself.

 

 

Soot comes from the unburnt fuel leftovers.  Oil ash comes from the oil that slips past the piston rings, and the particle size is larger and cannot be burnt off, this value is only estimated from the ECU calculations, a car that has wrong oil, or consumes more oil than average car will have a much higher real value than what is seen on readings (this cannot be measured)

 

Your car does have more soot than the car thinks it should have, but this happened to me recently where it was reading 15g measured (after trying static regen)  So a friend I know put some product into the DPF and the regen was able to bring the soot back down to under 1g measured (this comes from too many short journeys before I brought the car)

 

Mine now wants to regen still a fair amount, but I ignore it because even when it put the exhaust lamp on, both measured/calculated soot was low.

Stupid cars.

 

 

You could replace the DPF if that part is correct (price is very good if correct) and have trouble free motoring.

Maybe you can provide some car details into your signature on forum so that people can look up details.

1 hour ago, varooom said:

Soot comes from the unburnt fuel leftovers.  Oil ash comes from the oil that slips past the piston rings, and the particle size is larger and cannot be burnt off, this value is only estimated from the ECU calculations, a car that has wrong oil, or consumes more oil than average car will have a much higher real value than what is seen on readings (this cannot be measured)

 

Your car does have more soot than the car thinks it should have, but this happened to me recently where it was reading 15g measured (after trying static regen)  So a friend I know put some product into the DPF and the regen was able to bring the soot back down to under 1g measured (this comes from too many short journeys before I brought the car)

 

Mine now wants to regen still a fair amount, but I ignore it because even when it put the exhaust lamp on, both measured/calculated soot was low.

Stupid cars.

 

 

You could replace the DPF if that part is correct (price is very good if correct) and have trouble free motoring.

Maybe you can provide some car details into your signature on forum so that people can look up details.

Yes, but you can decrease the amount of soot with certain remedies, but there is no way to get rid of oil ash without physically removing the DPF and flushing it out, if I’m not mistaken.

26 minutes ago, Orman said:

Yes, but you can decrease the amount of soot with certain remedies, but there is no way to get rid of oil ash without physically removing the DPF and flushing it out, if I’m not mistaken.

Yes the soot can be burnt off, which is whole purpose of a DPF, and it can be "fixed" with some products as was in my own case.

 

Oil ash is oily stuff that probably can be partially washed away with chemicals no doubt, but not sure if it can be fully cleaned.  Other who have removed DPF for this have poor results (probably the Platinum itself is worn out, or coated in sticky oil ash residues)

3 minutes ago, varooom said:

Yes the soot can be burnt off, which is whole purpose of a DPF, and it can be "fixed" with some products as was in my own case.

 

Oil ash is oily stuff that probably can be partially washed away with chemicals no doubt, but not sure if it can be fully cleaned.  Other who have removed DPF for this have poor results (probably the Platinum itself is worn out, or coated in sticky oil ash residues)

Ah I see. Your friend that put the product in the DPF. Was it through the pressure sensor hole next to the DPF, or in the fuel tank?

14 minutes ago, Orman said:

Ah I see. Your friend that put the product in the DPF. Was it through the pressure sensor hole next to the DPF, or in the fuel tank?

Down pressure sensor hole before the DPF.

 

My soot was stuck at 15g, then dropped to under 1g after treatment.

18 hours ago, varooom said:

Down pressure sensor hole before the DPF.

 

My soot was stuck at 15g, then dropped to under 1g after treatment.

Do you remember the name of the additive/cleaner used?