Interesting reading, certainly seems like they put a lot of thought into it.
I recorded over 200 trips on my 2017 Discovery Sport to find out if its DPF is fit for purpose
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You probably cant tell about the amount of short runs. But yes I think as long as it isnt blocked beyond help then it could be cleaned with its own system and proper use, and work fine.
J
So if you apply what you have just read/learnt.
What would you think about the graphs in the OPs posts.
J
The ash level in the DPF is the canary - high ash content = lots of active regens and potentially cheap or incorrect engine oil used. I've seen DPF's that are >12 years old still performing as intended, some manufacturers fitted them way ahead of the mandatory date.
Ash is cumulative and cannot be reduced, it's 'measured' by a calculation involving a few factors, but mainly active regen time, DPF age and (for some mfr's) oil grade used.
If a DPF vehicle is 'used within the design parameters' then yes, you will be able to reverse the DPF soot load issues, what you should also look at is the inlet & charge air tracts beyond the EGR inlet(s), these will likely be choked with oily soot which will need removal - it won't self clear with sustained high temperature runs, just 'bake' in place, but once cleared, it will stay that way when 'used as intended'.
VW Tiguan low pressure EGR valve filter blocked due to low usage:-
Ash is cumulative and cannot be reduced, it's 'measured' by a calculation involving a few factors, but mainly active regen time, DPF age and (for some mfr's) oil grade used.
If a DPF vehicle is 'used within the design parameters' then yes, you will be able to reverse the DPF soot load issues, what you should also look at is the inlet & charge air tracts beyond the EGR inlet(s), these will likely be choked with oily soot which will need removal - it won't self clear with sustained high temperature runs, just 'bake' in place, but once cleared, it will stay that way when 'used as intended'.
VW Tiguan low pressure EGR valve filter blocked due to low usage:-
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Your experiments are interesting, I commend your diligence (200 runs) and your scientific approach.The DPF on my Land Rover Discovery Sport 2017 got blocked and had to be replaced (£2000+), a problem that seems to be affecting many of us.
I found out there was a class action lawsuit against Land Rover for faulty DPF construction, and I wanted to get proof of whether my car was also affected. (Further information about the issue is presented in this document: D8 Dilution Explained)
Using the Car Scanner app for iOS, I recorded over 200 trips in and outside of the UK and put all the recordings up on a website: https://sootscout.com
It is still a work in progress (I need to do further detailed analysis on my trips); however, I believe it already provides valuable insights for anyone who wants to understand how the DPF works.
I've attached a photo of the first recorded trip, which immediately showed that the DPF could not passively regenerate itself during normal driving conditions on the motorway. Notice how the soot mass keeps increasing despite driving on the motorway at speeds above 50 mph. Only an active regeneration at the end of the trip could clear the soot.
View attachment 327952
In contrast, here is another trip recorded on the German Autobahn with speeds well exceeding 80 mph. Interestingly, the DPF is working as designed here. Notice how the increase in speed can continuously spike the exhaust gas temperature to above 500ºC.
View attachment 327953
Could this mean that the "faulty" DPFs were designed to be used outside the UK, where speed limits are higher...?
The data can be explored further on the website. If you are affected by the same issue, I hope you find the information useful.
Even if you've never had an issue with your DPF before, I strongly recommend you start monitoring it, as it will be blocked sooner or later. Information about how to start monitoring is available on the website. It should also help with the oil dilution problem, as you will no longer turn off the engine at the end of your trip if you see that a regen is in progress.
PS: If you send me your recorded trips from Car Scanner (CSV format #2), I would be happy to convert them to a chart similar to what I have done with my trips. Then, we could compare how the DPF functions on various Land Rover models.
Cheers.
My comments on your graphs for Dpf soot build-up at a 50 mph journey and an 80/90 mph journey.
Please note during the Euro emissions tests the vehicle Is driven mainly in the 30 to 50 mph range of speeds, an optional short burst of speed of 75 mph is allowed, 80 to 90 mph running is not valid therefore not tested.
So when the vehicle is driven at greater than 75 mph, the Euro-standards do not truly apply, the vehicle is never run at 80/90 mph during the Euro-test, for 80/90 mph ,the LR engineers can choose calibration settings without constraint for the Euro Nox limits, Lr engineers may have used that to their advantage by ECU calibration of high-speed engine operation for a Dpf-friendly low-soot /high Nox combustion strategy when the vehicle is operated at high speed, in my opinion such a strategy explain the high to low soot change shown in your 90 mph graph.
At 50 mph speed, Euro standards will need careful observation and compliance, the engineers will be calibrating for low Nox , lowering Nox levels will be traded off high soot generation.
Nox is also part of passive regeneration, high Nox is a catalyst for soot removal, which explains your "autobahn" graph where soot load decreases without active regeneration taking place
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