DPF maintenance, worth it?
Discussion
I’ve picked up a cheap Mini diesel (N47) on 120K to play around with. No history but its got a new turbo, egr and a stage 1 map so its a bit of fun and costs nothing to run…. (Ok new bearings, discs, pads, calipers etc etc)
Bimmerlink shows the DPF is regenning regularly with oil ash at 39g. I have a couple of cans of DPF cleaner on the shelf unused and I’m trying to determine what or even if I should bother doing anything?
Please correct anything I’ve got wrong, I’m coming from a place of ignorance on this...
My understanding is that under ideal conditions a DPF should last 150K+, maybe more. The eventual failure being caused by the build up of oil ash restricting the flow of gasses through the DPF which creates pressure resulting in the car/engine producing error codes or going into limp mode etc.
Correct?
Oil ash builds up over the life of the DPF and is not removed or reduced by the the DPF performing regens. A regen reduces soot which builds more rapidly than oil ash but should not build to levels that are problematic if regens are performed as determined by the car. A regen burns off soot by increasing the temperature of the DPF by running the engine at higher rpm for a prolonged period.
Correct?
Premature failure or problems caused by the DPF are often due to regens not being performed as determined by the car causing soot levels to build. This can be mitigated by forcing a regen and/or using chemicals to help break down the soot and/or allow it to be burned off at lower temperatures.
Some additives also remove oil ash and can be used whilst the DPF is in situ as part of the regen process. Others require the removal of the DPF for the cleaning process.
Correct?
If I’m right so far a DPF subject to regular regens where soot levels are managed is not an issue until back pressure becomes problematic. This can be managed by reducing or removing the oil ash removal through cleaning.
However, soot and oil ash levels are largely calculated and not always actually measured. Therefore any figures shown by the ECU for for soot or oil ash levels may or may not be actually correct.
Therefore a real world indicator of DPF health is the pressure level before the DPF?
Correct?
On thie basis the above is not just made up drivel, 2 questions...
1) Is there any point in removing oil ash by whatever means without updating the ECU to reflect this? Or, is the ECU going to look at the pre-dpf pressure level to determine the DPF condition?
2) Irrispective of what the ECU thinks, is reducing the pre-dpf pressure a significant thing? Google says yes but is 1.01bar at idle really all that bad?
Any guidance appreciated.
Bimmerlink shows the DPF is regenning regularly with oil ash at 39g. I have a couple of cans of DPF cleaner on the shelf unused and I’m trying to determine what or even if I should bother doing anything?
Please correct anything I’ve got wrong, I’m coming from a place of ignorance on this...
My understanding is that under ideal conditions a DPF should last 150K+, maybe more. The eventual failure being caused by the build up of oil ash restricting the flow of gasses through the DPF which creates pressure resulting in the car/engine producing error codes or going into limp mode etc.
Correct?
Oil ash builds up over the life of the DPF and is not removed or reduced by the the DPF performing regens. A regen reduces soot which builds more rapidly than oil ash but should not build to levels that are problematic if regens are performed as determined by the car. A regen burns off soot by increasing the temperature of the DPF by running the engine at higher rpm for a prolonged period.
Correct?
Premature failure or problems caused by the DPF are often due to regens not being performed as determined by the car causing soot levels to build. This can be mitigated by forcing a regen and/or using chemicals to help break down the soot and/or allow it to be burned off at lower temperatures.
Some additives also remove oil ash and can be used whilst the DPF is in situ as part of the regen process. Others require the removal of the DPF for the cleaning process.
Correct?
If I’m right so far a DPF subject to regular regens where soot levels are managed is not an issue until back pressure becomes problematic. This can be managed by reducing or removing the oil ash removal through cleaning.
However, soot and oil ash levels are largely calculated and not always actually measured. Therefore any figures shown by the ECU for for soot or oil ash levels may or may not be actually correct.
Therefore a real world indicator of DPF health is the pressure level before the DPF?
Correct?
On thie basis the above is not just made up drivel, 2 questions...
1) Is there any point in removing oil ash by whatever means without updating the ECU to reflect this? Or, is the ECU going to look at the pre-dpf pressure level to determine the DPF condition?
2) Irrispective of what the ECU thinks, is reducing the pre-dpf pressure a significant thing? Google says yes but is 1.01bar at idle really all that bad?
Any guidance appreciated.
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