BMW 320d F31 engine check light on DPF warning
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F31 BMW 320d Touring
engine check light on
At intake/EGR carbon cleaning
We had a visitor from Saitama Prefecture.
Thank you for your request from far away.
Let's start with the diagnosis.
Contains fault memory.
・Significant load on DPF (high back pressure)
- Malfunction of EGR valve
There is a memory of these failures.
DPF load means that the DPF tends to be clogged.
Carbon buildup on the intake side has a major effect on DPF clogging.
Combustion efficiency decreases due to the intake path becoming narrow due to soot accumulation.
Furthermore, this leads to a vicious cycle of increased soot production, resulting in the DPF becoming clogged.
Let's remove the intake and EGR.
Check the condition of the carbon on the removed parts.
Intake manifold body
Accumulation is progressing.
intake pipe
EGR confluence point
Inside the EGR cooler
Soot tends to accumulate on the cooler outer walls.
We will scrape by hand as much as possible.
Although it is quite a difficult task,
Preparation before ultrasonic cleaning is very important.
This is the condition inside the intake port.
After cleaning
By eliminating the deposits around the valve
This has the effect of reducing engine noise.
*We have newly introduced a walnut blaster that uses walnut shells.
In addition to the conventional manual cleaning, it is now possible to perform cleaning with even higher precision.
(The image is an example)
Next, ultrasonic cleaning around the intake and EGR
After soaking for several hours, it is finished by blasting.
Parts after cleaning
It will be as clean as new.
The coolant pipe cannot be replaced without removing the intake manifold.
We are replacing them at the same time as there have been an increasing number of cases where they cracked and coolant spewed out.
EGR valve with error memory
This time, after consulting with you, we will clean it and reinstall it.
After assembly, perform air bleed, check for leaks, and road test.
The accelerator pedal opening percentage will be lower than before the work.
This directly leads to improved response and fuel efficiency.
After work, the DPF will be unclogged.
You can check the data showing smooth improvement in intake and exhaust.
Why did I clean the intake side instead of the DPF?
By resetting carbon deposited in the intake and EGR
・Difference in sensor value
・Difference in fuel injection amount calculation
・Combustion efficiency
We believe this is because these issues have improved and the amount of soot generated during combustion has decreased.
From DPF fault memory
・DPF cleaning
・Replacement of DPF body
There seem to be cases where something like this is proposed.
We believe that DPF cleaning alone is meaningless .
No matter how much sand is cleaned downstream,
If we don't stop the sediment flowing from upstream,
It's back to normal in no time! I think it's easier to understand if you give an example.
There is always a reason why the DPF tends to clog.
Combustion efficiency decreases due to intake passage becoming narrow due to soot accumulation.
The DPF tends to become clogged due to the increased amount of soot generated during combustion.
Furthermore, the accumulation of soot in the intake accelerates via EGR, leading to a vicious cycle.
- DPF clogging (high back pressure)
・Decrease in response
・Decrease in fuel efficiency
``The root of all evil is this ``intake clogged with soot.''
However, this is not a malfunction or defect.
Due to the structure of diesel engine EGR, this cannot be helped.
The only way to remove the accumulated material is to physically clean it.
It is also true that cleaning can restore performance close to its original state.
By also cleaning the DPF
The effect is even greater through interaction.
long! Happily! Stay well!
For users who want to associate with BMW / MINI diesel cars
We provide EGR/intake cleaning and DPF cleaning services.