DPF questions

[GreyWolf]

Hi,

For anyone with the 3.0L TDI engine.

1. If you use a monitoring tool for the DPF have you ever noticed a sudden jump (>15%) in soot% for the calculated soot mass?
(If anyone knows how this value is calculated would be great. It appears as per the manual it incorporates air mass flow, lambda, dpf/turbo EGT's & DPF differential pressure sensors)

2. I am curious if I have an intermittent sensor issue. Have you needed to replace Lambda (G39) or DPF pressure sensor (G450)?

Cheers,

Greywolf

[Lucas_R]

I have a 3.0L TDI in an Audi SQ5 and keep a very close eye on the DPF and its operation.

If you are having a 15% increase in soot then I’d be pretty certain that your DPF pressure sensor is on its way out. There is 1x sensor before the DPF and 1x sensor after the DPF and it measures the pressure difference pre and post DPF to calculate how full the DPF is.

The DPF pressure sensors are generally quite a cheap part (<$200) so might be wise to replace it - unless you have access to a good quality scan tool to test the various sensors to pin point the culprit.

This ‘should be’ the correct part, but probably a good idea to check the part # from your current one. FOR VW AMAROK TOUAREG S6 S4 Q7 3.0TDi DPF PRESSURE SENSOR DPF 059906051J GENUINE | eBay

[GreyWolf]

Hi Lucas_R, thanks for the reply.

In preparation I will find out genuine part numbers. In researching I noticed that the sensor may require calibration (adaption) to the DPF.

Do you happen to know difference between the calculated soot mass vs measured & which one is used to activate the burn?

Out of curiosity does the Audi 3.0L have the DPF after the cat or the combo DPF/Cat?

Cheers.

[Lucas_R]

The apps I use (VAGDPF and Carista) just shows the Soot Mass Calculation value, the Soot Mass Measured value does not populate for my car. So I can only assume it uses the Soot Mass Calculation to determine when a regen is needed.

When the Soot Mass Calculation reaches about 21-22grams the DPF is full and it will trigger a regen. On the Audi it has 2x DPF's that are under the car next to the gearbox which makes them nice and easy to access/remove. There is a cat just after the 2nd turbo, and then the 2x DPF's under the car.

Watch this video which might give you some tips on locating the pressure sensor - skip to about the 4 minure mark:

[GreyWolf]

With the Carista app does it allow a manual DPF regen while driving? This would allow better operation of the dpf as opposed to rolling in the driveway when it is ready to burn. It's surprising while monitoring how often this happens.

Unfortunately it is difficult to get the exact function/initiation of the DPF. I still believe there are software issues similar to below thread.
Newbie Amarok V6

For anyone interested
https://www.vwaudiforum.co.uk/forum/...0/14956.attach


Not sure if other car brands have the following button. I am led to believe this button was a result of the class action.
Just a moment...


It would be interesting to know what other brands have as standard for monitoring or controlling the DPF without a 3rd party addition.

[Lucas_R]

Yes Carista is the app i use most often and it allows you to trigger a regen while driving. After you press the regen button it takes about 5 minutes before the regen process actually begins.

[lloydus67]

Hi Greywolf
During the 140,000 klms that I had my Dpf in my V6 Amarok, I didn’t notice it do a burn at all. However I do a lot of towing and highway mileage. Many apps allow you to do a manual burn, however forced burns are likely to shorten the life of your Dpf before you need to replace it.
In answer to your question, no Amarok’s do not have a manual burn button. As you said Toyota only put them in for a limited number of years after a class action against them. Manufacturers don’t want you doing manual burns as it reduces DPF lifespan.
Lloyd


Sent from my iPhone using Tapatalk

[Lucas_R]

Hi Greywolf
During the 140,000 klms that I had my Dpf in my V6 Amarok, I didn’t notice it do a burn at all. However I do a lot of towing and highway mileage.

The thing is that you never know the car is doing a DPF regen unless you happen to switch the engine off while one is in progress - as the engine fans will be running like crazy which I believe is a safety feature to blow air over the engine/exhaust to help keep the termperature from getting too hot. If you do a lot of highway driving then chances are that 90% of the time, you are doing a regen while doing 80-110kph which are perfect conditions.

The only telltale sign on my car is the instant fuel consumption readout which you can only notice if you are idling, it goes from 0.8L/100kph to 1.1L/100KPH which the the additional fuel being injected to heat up the exhaust to get it hot enough to burn off the soot. The exhaust note also changes a bit and there is a bit of a different smell from the exhaust, but once again you can only notice it if you are idling.

As you mentioned, I know Toyota Landcruisers has a DPF burn button fitted to some of the 200 series models for a period of time - but they are the only manufacturer that I am aware of who has done this. Im not sure if Hilux's and Prado's also had this feature, or if it was just the Landcruisers.

[GreyWolf]

Hi Lloyd,

I suspect you may have noticed the idle rpm raised to approx 1000rpm when sitting at traffic lights. That's about the only indicator you get unfortunately. I have also noticed the fans as Lucas mentions if interrupting a burn cycle.

I am also aware of the requirement to drive with load & longer distances as it is indented to be. I have also had a trailer on driving consistent 3hrs (multiple times) & received the DPF light of death. I think it is possible (unlucky) that you end up doing a few short trips & interrupt the burn cycle.

In my experience, consistently monitoring the DPF sequence, there is minimal passive burn as it does not enter the required EG temps required to complete an efficient burn. (650C) approx 280-300km cycle

I can not see any difference between a forced regen or an active regen as it would be the same process. I imagine the only difference for a forced regen would be because the soot % is too high & requires monitoring during the burn.

I was thinking it might be better to enable an active regen based on drivers awareness of the system & known travel route (for burn requirements) as opposed to blindly hoping your next drive matches the burn requirements.

The system to protect itself is supposed to warn via the dpf light to go for a drive but I have seen it go into limp even before this warning.

[GreyWolf]

In my treasure hunt for other DPF victims, there was someone else on this forum that was towing a trailer on holidays near Hay & had issues clearing the alarm. Wish I had saved it or could find it again.