Issues regarding the EGR (before and after cleaning)

Hi,

I recently acquired a 2005 C3 1.4 HDi 16V which is good for now but before purchase seller informed me that engine light comes and goes seldomly and it was not creating any powerloss or any other major issues(a small amount of blackish smoke only when try to accelerate hard).

As an engineer myself I could not resist to check the issues and I connect an odb device and check fault codes, I cleared them and go for a test drive.
Resulting alarms were;
1341 and 400(ish) alarms which was glow plugs and egr system, respectively. Also found that glow plugs are not trigger engine light but egr is.

Then I removed egr valve for cleaning, cleaned it, checked it(it was a bit hard to move but it seems it is normal), put it back, everything was normal until this point.

I found a pipe that was connected no where or appears to be connected no where as I pulled it without any force It just come off.
I could not found where it was connected(if it was connected) then I just put everything back(without pipe) and started the engine.

Checked alarm codes and only glow plug was active. But then a new code appeared
2143 which I found as "egr vent open circuit" This code is appearing even after clearing fault codes but there is no engine light active right now and car do not have any power issues and again only a small amount of black smoke.

Soooo,
1 - I want to ask what is this pipe? Is it related to egr system ? or just a breather pipe of some other place ?
2 - I found out my egr is vacuum controlled which is also controled by a selonoid valve, 2143 probably means selonoid is electrically open-circuit(burned? but I did not touch it and can not touch it as it is very far back side of engine and could not even reach it to check it) ?
or Egr itself does not work and engine is getting this "egr vent open circuit" feedback from somewhere else ? (Like a sensor, I found some engines test egr by using intake manifold pressure sensor)

I checked egr vacuum pipe by hand and it was providing very low vacuum which is no where near enough for the egr valve as my fingers nearly bruised when I try to move the diapragm by hand(egr broken maybe ?). And Maybe it was not trying to open egr as car was idling.

Btw MAF and MAP sensors are also cleaned by a contact cleaner after 2143 alarm appeared, Intake manifold was very dirty I suspected maybe there is some soot over sensors. Sensors are working as they should be(odb sensor info).

Sorry for very long description but I was working on the engine nearly two weeks to solve and reach conclusions. I dont want to go to a mechanic to tell me this needs change that needs change by trial and error technique(been there done that).

Hello

You test the vauccum controlled EGR valve with a 'mighty vac/vacuum pump' type of device. This provides a vacuum on the EGR and you can then prove it operates under a vacuum, and that it will hold a vacuum. If it won't operate under a vacuum or it won't hold that vacuum, replace it.



The pipe you removed looks like the EGR electrovalve vent. Although this does seems to be something they added to the last of the 16v diesels because it is a bit different to the early models. Anyway, I would look behind the engine for the EGR electrovalve and look for a spigot on the valve that is missing a pipe. I would say this is your vent pipe.


If you can't reach the EGR electrovalve you need to remove the air filter box, this will then give you all the access you need to reach it.

This topic has pictures of the air filter box removed from a 1.4 HDi 16v C3 that may give you some hints on how to remove yours.

C3CAR wrote: ↑Fri Jul 03, 2020 5:37 pm Hello

You test the vauccum controlled EGR valve with a 'mighty vac/vacuum pump' type of device. This provides a vacuum on the EGR and you can then prove it operates under a vacuum, and that it will hold a vacuum. If it won't operate under a vacuum or it won't hold that vacuum, replace it.



The pipe you removed looks like the EGR electrovalve vent. Although this does seems to be something they added to the last of the 16v diesels because it is a bit different to the early models. Anyway, I would look behind the engine for the EGR electrovalve and look for a spigot on the valve that is missing a pipe. I would say this is your vent pipe.


If you can't reach the EGR electrovalve you need to remove the air filter box, this will then give you all the access you need to reach it.

This topic has pictures of the air filter box removed from a 1.4 HDi 16v C3 that may give you some hints on how to remove yours.

Thanks for explanation, I already removed air filter but still it is very hard to reach. Also if it is like you say just a vent pipe, it should not cause any problem(electrovalve-wise). Anycase I need to check if that valve is broken or not.

On the early models the vent is part of the valve, it looks just like yours without the long pipe attached.

Citroen must have found a problem with the vent being in that position and made a modification.

I don't know how much effect it will have, but it does sound like it's monitored so there must be a reason for that.

With the air filter box removed the valves become accessible, you can't see them but you can feel them. Only two bolts and a 2 wire electrical plug hold them in place.

It is just as easy to just replace the eletrovalves and worth doing if they are suspect or old. It takes the same time remove the old one and put the old one back on as it does to remove the old one and fit a new one.

This is why the vacuum pipes seem to just fall off.

Quite common on the C3