DPF Issues

[J Dodwell]

Hi All,

Having some of the dreaded DPF Issues. Bought a c-class w204 OM651 with faults. Replaced the wastegate solenoid, EGT Sensor pre cat, and the DPF pressure sensor. which has cleared all the faults, however the DPF is now full. Bought a icarsoft scanner yesterday and tried to force regen and it is saying the fill level is too high (402%). Any ideas on the next step before taking the DPF off and cleaning it? I saw something about resetting the DPF fill level, no idea if this is possible on the icarsoft as ive only just got it and I'm fairly new to this stuff. Any advice will be appreciated.

 

[LostKiwi]

Star/Xentry may be able to force a regen.

 

[J Dodwell]

Trying to avoid paying out anything more at the minute if possible. If there's no other options, then ill have to do that. Just mainly need to know if its possible & safe to reset DPF levels with the equipment I've got.

 

[bladecrazy]

you could try the foam areosols down the dpf sensor pipe then take for a run, try a regen afterwards.

 

[J Dodwell]

you could try the foam areosols down the dpf sensor pipe then take for a run, try a regen afterwards.

I have tried that, it seemed to restore a little bit of mpg but nothing else.

 

[J Dodwell]

I have tried that, it seemed to restore a little bit of mpg but nothing else.

although I did it through the O2 sensor and not pressure, not sure it will make any difference though?

 

[w204benz]

Definitely do not try to force a regen if the fill level is that high.
There is a reason that option gets locked out - if there is too much soot in the DPF when trying to burn it off, the temperature can get so high that the DPF will melt. And that would be a much more expensive problem to fix!

Really the only options are cleaners like @bladecrazy suggested or an off-car DPF clean. Then you can reset the fill level and it should be fine.
Unless someone has already tried to force a regen and damaged the DPF.

You could also check out O'Rileys Autos on YouTube, I think he has a few videos cleaning w204 DPFs.

O'Rileys Autos

O'Rileys Autos strive to be the best YouTube Channel for Mobile Mechanic Car Repair and Diagnostic videos. Weekly uploads of real life Repairs and Auto maintenance plus Diagnostic videos specialising in diesel & petrol emissions fault repairs. Automotive Repair Tutorial channel Diagnostic...

www.youtube.com

 

[J Dodwell]

Thanks for that, trying to look more into what is actually wrong as nothing seems 100% convincing. Trying to make sense of the readings of my scanner and it shows 3g soot level, but 400% fill level. Im only a novice so might be wrong here, but can it be 3g and 400%?.

 

[bladecrazy]

I used silver hook dpf cleaner , i put it down the pressure sensor pipe and let it sit for an hour then when it was dark took it for a good blast , came home then forced a regen , as has been said it wont do a regen if to blocked.

 

[J Dodwell]

Just been trying to make sense of the readings as they dont quite add up, but I'm thinking the dpf isnt blocked but the pressure sensor hoses are.

 

[mioba]

Did you recalibrate the diff press sensor.

Did you blast compressed air down the sensor pipes when the sensor was off.

If you got the cleaner down the pipes then i would doubt they are blocked

 

[J Dodwell]

Did you recalibrate the diff press sensor.

Did you blast compressed air down the sensor pipes when the sensor was off.

If you got the cleaner down the pipes then i would doubt they are blocked

Was not aware I had to calibrate it, will have to find out how. I didnt manage to get any cleaner down it, but I just presumed it was because I was using mannol cleaner which is a very high foam so just shot straight back out. I will try and borrow a compressor this weekend and give all three options a go

 

[M80]

Check the wiring to the DPF sensor.
I'm not familiar with yours but it can run around the bulkhead above the exhaust.
If it has dropped onto the exhaust previously it could have melted together.

 

[mioba]

Check the wiring to the DPF sensor.
I'm not familiar with yours but it can run around the bulkhead above the exhaust.
If it has dropped onto the exhaust previously it could have melted together.

That would trigger EML immediatly. The wiring is pretty good to avoid that as the sensor is on a clamp high up.

 

[J Dodwell]

would anyone know if the 400% fill amount is wrong if the DPF pressure sensor is giving the correct readings. 0 bar at idle and 0.13 whilst driving (i think it was 0.3 but will need to check again as I cant remember) and do those figures even sound right?

 

[Dean Fletcher]

I have tried that, it seemed to restore a little bit of mpg but nothing else.

Did you spray dpf cleaner down both pressure sensor pipes both upstream and downstream?

 

[Dean Fletcher]

would anyone know if the 400% fill amount is wrong if the DPF pressure sensor is giving the correct readings. 0 bar at idle and 0.13 whilst driving (i think it was 0.3 but will need to check again as I cant remember) and do those figures even sound right?

Needs to be close to -0.004 and 0.004 at idle and should go up a little with revs

 

[J Dodwell]

Did you spray dpf cleaner down both pressure sensor pipes both upstream and downstream?

Just upstream as I was rushing around. Will give it a proper clean out on both pipes this weekend and blow some air down it

 

[mioba]

A problem with the diff pressure sensor will kick on an EML

 

[J Dodwell]

Needs to be close to -0.004 and 0.004 at idle and should go up a little with revs

It was .01 at idle and .07 revving the engine and little whilst parked