Soot on rear doors Expert 2.0 HDi (DW10CD)

[jsoap]

Recently aquired an Expert 2.0 HDi (DW10CD), 2015 model 48k miles. Have had it out for a few runs on the motorway and noticed many spots of soot on the rear doors whe I got home. I'ts been sitting on the drive for a few weeks, with ocasional starts. So I did a run of 60 miles on the motorway yesterday (70mph, 2k revs, and soot on the doors. Did the return journey today and no soot.
Havn't noticed any black smoke out of the exhaust, though the inside of the tailpipe is black. There are no fault codes showing, no warning lights and performance seems normal. Have done a lot of searching for similar issues with few results. I'm thinking that the regen process is kicking off as expected but the soot is not being bunrt off. Anyone got any ideas?

[GiveMeABreak]

Hi and welcome.

There really shouldn't be any soot released with a particle filter - as that's its job to prevent particles from getting into the atmosphere - so that begs the question.... are you certain that the previous owner hasn't had it removed? It's becoming an issue on the second hand market.

Any smoke now on one of these is an MOT failure - so may be worth getting it checked out - a mirror should show if it has been tampered with.

[jsoap]

Hi, thanks for the quick reply. Yes this did occur to me, but that would not explain why there is no soot today on essentially the same journey as yesterday.

[GiveMeABreak]

It is possible that it is there of course - but also possible the soot was picked up from somebody else polluting ahead of you

Or it may be a bit of harmless ash from a regeneration cycle.

[jsoap]

I seen the soot the last time I was out a few weeks ago on a 200 mile trip, so I'm pretty sure that it's me. Its definitely soot and rubbing my finger inside the tailpipe it's very dark black. I'd expect a light colour if it was ash.

[GiveMeABreak]

So hooking it up to Diagbox and seeing what the Injection ECU has to say may be the way to go. It will normally provide details about soot levels and additive quantity injected - if that data is missing then I think you have your answer.

[jsoap]

Thanks, I'll have a go at that (once I get diagbox working on my laptop).
I just checked again with my generic reader and there is a fault logged P11AA - this happend as I was pulling out of my driveway to a steepish hill, maybe a little too sharpish - the service light flickered on an off again. Probably not related but worth a mention.

[GiveMeABreak]

That would seem to relate to inlet manifold pressure sensor signal fault: Pressure too high. So it's making me wonder if there is any crud blocking the manifold intake. Maybe worth taking it off and cleaning it out. There may well be an oily residue in there, which may cause the odd hiccup if some of it breaks up and gets in.

[jsoap]

Spent the last 2 days installing and updating Diagbox (have been putting this off for a while). So tried with v7.57 and I get F5FF Unexpected re-initialisation fault coming from the BSI and Injection ECU not recognised. Updated again to v7.61 and still the same. Cracked open the Lexia adapter and it's not a full chip version, so I suspect that I'll need a new interface.
In the meantime I wondered if the android app "FAP Citroen/Peugeot" might help - have tried the lite version and it seems to work ok.

[GiveMeABreak]

It may well do as a stand in, but won't come close to a Lexia.

If you do get another Lexia kit (full chip of course), make sure you don't update past 7.62 or you'll start loosing manual telecoding functions.

If it helps, there is a forum discount for members from a supplier that is recommended by members here:

viewtopic.php?f=13&t=60113

[jsoap]

I got the app so that I do a quick diagnosis, but will probably update the Lexia later.
So the app is able to communicate with the DCM_BR2 fitted to the van.
Intial reading are as expected - last regen 125km, FAPlife distance, soot level, FAP pressure etc.
However it would seem that the EGR coolant bypass valve is not closing when the engine warms up - so when the EGRBypassInstr switches to 0%, the EGRBypassPos stays as it is at !00%. Obviously not a good thing for engine temperatures, but not sure if this would cause the soot problem.
Another thing of note is the average distance between regens (last 10) is 140 miles!

[jsoap]

Conveniently the EGR coolant bypass valve is easily visible on the front of the assembly. When the engine is started, after a second the signal to open the valve is sent, and the vacuum solenoid activates, pulling the valve open. So it looks like it's just a reporting issue from the position sensor. Noticed that when the ignition is on, there's a whining noise from the EGR - which carries on for 30s after the ignition is turned off. Probably just the stepper motor being cycled

[GiveMeABreak]

Yes it is normal for that noise from the solenoid valve after switching off.

I don't have details of your specific system, but on the DW10CTED engine (Euro 5) here is a little about how the EGR valve is opened and closed and cleaned, as well as a bit on the EGR Gas cooling: This is for a Delphi system
Cooling of the recycled exhaust gases

• Cooling of the exhaust gases enables the emissions of nitrous oxide (NOx) to be further reduced.
• The exhaust gases are able to be cooled, in order to prevent the total mix of air from reaching too high a temperature (Mixture of inlet air and recycled exhaust gas).
• In certain operating phases, the exhaust gases do not have to be cooled before being admitted into the combustion chamber (Notably during cold starts, to allow the engine to warm up more rapidly).
• The engine ECU, by means of a pneumatic electrovalve, operates a by-pass by which the exhaust gases go directly to the air inlet without passing through the EGR exchanger.

Initialisation of stops
To mitigate ageing and soiling of the EGR valve, an automatic initialisation of the high and low stops is performed when the EGR valve is at one of these limits for more than 0,5 seconds.
Taking account of the stop positions initialised automatically and comparing them with the original position initialised at the factory, the engine ECU adapts the setting for control of the EGR valve.
Initialisation of stops is not possible if the battery voltage is lower than 10 V or higher than 14 V.

Cleaning

• To prevent soiling of the electric EGR valve, there is a cleaning phase on switching on the ignition.
• This cleaning phase consists of one or more successive opening and closing cycles.
• At the end of the cleaning cycle, the engine management ECU tries to reach the upper stop (maximum opening) of the electric EGR valve.
• If during this attempt a blockage is detected, the cleaning cycle is repeated.
• If, after this second attempt, the valve remains stuck, a fault appears.

Antisticking
The engine ECU estimates the state of sticking of the electric EGR valve, as a function of the following factors:

• Speed of movement of the gate of the electric EGR valve
• Errors in regulation of the position of the electric EGR valve

If the electric EGR valve is stuck or is beginning to stick, the engine ECU commands the electric EGR valve via a conventional control signal.
This signal is followed by a vibratory signal that makes the gate of the electric EGR valve vibrate in order to prevent the sticking.

N.B. : The amplitude of the vibratory signal depends on the degree of sticking detected by the engine ECU. The antisticking strategy is used only during phases where the electric EGR valve is being operated.

• "G" Zone of activation of the electric EGR valve.
• "N" Engine speed.
• "T" engine torque.

The electric EGR valve is deactivated in certain operating conditions:

• Under conditions of engine speed and engine torque defined by the zone of activation "G"
• At idle for a maximum time of 300 seconds

The exhaust gas is not cooled in the following conditions:

• Engine torque below 140 N.m
• Engine speed below 2500 rpm
• Coolant temperature between 15°C and 60°C

[Paul-R]

The exhaust gas is not cooled in the following conditions:

• Engine speed below 2500 rpm

Ha! That's 99.9% of the time when I'm driving then!

[jsoap]

Thanks for that - I thought the 2500rpm a little odd too. Probably means under 60C AND less than 2500rpm. I can see cooling cutting in at 60C when idling.
Now that I can see and log whats happening I'll do do a few trips to see what happens when the regen starts again.