Forcing diesel particulate filter regeneration - good or bad?
DPFs help reduce emissions and capture harmful particles and soot from being released into the atmosphere.
In order to prevent DPFs from clogging, they must pass through a regeneration cycles every few minutes to safely burn the particulates and retain the soot until the next regeneration cycle.
When the vehicle is generating more soot than normal or the DPF ceramics are in poor condition, the regeneration cycle is shorter, and over time it may even be necessary to force a regeneration if it becomes too clogged.
Particulate filter regeneration force contents
What is particulate filter regeneration?
Particulate filters are designed to contain harmful particles and to be able to regenerate themselves from time to time.
This process of filling, cleaning and emptying is called regeneration of the particulate filter.
The soot created by the vehicle's combustion process is retained in the DPF ceramics and then burns off, preventing the DPF from blocking and trapping more soot.
In order to perform this regeneration, the diesel particulate filter must reach high temperatures.
When a DPF reaches a particulate matter (PM) fill level At the default setting (around 40%), the ECU will activate the regeneration process, which can inject up to eight times more fuel per stroke, a rate that is needed to produce temperatures around 500°C.
There is two types of regeneration to achieve this: active regeneration or passive regeneration, although some engines use a combination of both.
Passive particulate filter regeneration
The passive regeneration of the particulate filter occurs when driving for long periods of time at high speeds and very high temperatures are reached in the exhaust system.
Driving at 110 km/h or more for a period of time will heat up the exhaust sufficiently to burn off the soot particles that have been trapped by the DPF.
Active particulate filter regeneration
Because drivers often do not drive on motorways or high-speed roads, manufacturers came up with the idea of active regeneration.
The active regeneration of the particulate filter occurs when the soot level in the DPF is around 40-45 % of its capacity.
When the soot reaches this percentage, afterburner fuel is injected to increase the exhaust temperature.
In this way, even if the vehicle is not travelling at high speed, the exhaust system gets hot enough to burn the soot from the DPF and perform the regeneration.
What is the problem?
When the vehicle is stopped before regeneration is complete, a warning may appear on the dashboard.
If you don't drive for another 15 minutes or so, the regeneration is interrupted and that is not good.
When this happens several times, the soot builds up more and more until it reaches high levels of saturation.
When can regeneration not take place?
There are some reasons why regeneration may not take place:
The engine management light illuminates in the event of a fault.
There is less than 20 litres of fuel in the fuel tank or the fuel light is on.
Pressure sensors are not working properly.
Pressure sensor pipes are damaged: check for degradation under the heat shield.
The EGR system is not working properly.
The engine oil is of the wrong specification for the vehicle; it should be low ash grade.
The fuel additive level is too low.
Force regeneration of the particulate filter
In order to carry out a forced particulate filter regenerationIf you are using a diagnostic scanner, it is necessary to use a diagnostic scanner.
The forced regeneration process can take up to 30 minutes.
DPFs require more maintenance than catalytic converters.
The ash from the engine oil accumulates on the inner walls of the ceramic and in the pores.
This increases the pressures in the DPF and if clogged, can even damage the engine.
Therefore, the regenerative capability of the DPF is vital to avoid failures in other systems.
When installing a new DPF, the ECU must be reset so that the system knows that the values are those of a new DPF and the malfunction warning is not triggered again.
So, is it good to force DPF regeneration?
Sometimes yes, sometimes no.
Depending on the saturation state of the DPF it may or may not be suitable.
When high saturations are reached and the temperature rises too high, the retained material inside may expand and fracture the ceramic and spoil the particulate filter.
This is due to the fact that not only soot accumulates, but also ash from oils and wear and tear of the components themselves.
The asheven if the combustion process is carried out during regenerations, is not eliminated and is saturating the DPF.
Therefore, to remove this ash, it is necessary to clean the particulate filter with a machine that removes the ash and soot and the internal walls are left with their filtering capacity as good as new.
How can this be done? I think you are on the right website ; )
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