C4 GPII 2.0 BlueHDI fuel consumption

[arielkiraly]

Hello guys,

I have a 2014 Citroen C4 Grand Picasso II with the beautiful 2.0 BlueHDI engine in it.
I love the car, but other the engine itself, it has issues basically with everything else...

So the thing i write this post is that since about 2 weeks now, or more, my car use EVERY fuel in the world. Before it has 5.5-6L/100km, now it "eats" 8-8.6L/100km...
I also noticed that my side mirrors are almost ALWAYS hot. When the particle filter is cleaning, it's hot, i know, but we've checked it, it was successful around 2500km ago, and my particle filter is almost "clean"(less then 15% if i can remember right), but my mirrors are hot, and the engine behaves a little strange. It's powerful as it was before, but it's sound strange, not normal.

Infos: Adblue tank was changed 2 years ago(maybe 3?), now turned off, because it went broke again, and we needed the vehicle abroad.
Oil tank sensor was turned off. It can sense the oil level and maybe the viscosity of the oil? IDK, because it was limiting the engine...It was changed or deleted around 5 years ago.

Do you know what can cause such a problem? I'm paying my a$$ off nowadays...

Ty!

[GiveMeABreak]

This is perfectly normal!

When the engine ECU decides the particle filter needs regenerating and depending on the driving conditions and the vehicle's engine temperature and other data at the time of the regeneration, the engine ECU may switch on power consuming equipment. So the heated rear windscreen and the mirrors are examples. This action puts a greater load on the engine and in so doing helps get the engine to the temperature needed for regeneration.

The other thing you are noticing like the noise, is probably post-heating, where again the engine ECU is injecting extra fuel to raise the temperature more rapidly.

So of course, fuel usage will increase slightly during this process. If you do short stop and start trips then the exhaust gasses are unlikely to get hot enough to regenerate the particle filter - so will try and use assisted regeneration more often when the filter gets clogged up.

The Adblue system is entirely separate, and performs another function, so and has nothing to do with this.

If I were you I would get the sensor you removed / deleted reinstated. These have a purpose and removing them will cause other issues.

[arielkiraly]

This is perfectly normal!

When the engine ECU decides the particle filter needs regenerating and depending on the driving conditions and the vehicle's engine temperature and other data at the time of the regeneration, the engine ECU may switch on power consuming equipment. So the heated rear windscreen and the mirrors are examples. This action puts a greater load on the engine and in so doing helps get the engine to the temperature needed for regeneration.

The other thing you are noticing like the noise, is probably post-heating, where again the engine ECU is injecting extra fuel to raise the temperature more rapidly.

So of course, fuel usage will increase slightly during this process. If you do short stop and start trips then the exhaust gasses are unlikely to get hot enough to regenerate the particle filter - so will try and use assisted regeneration more often when the filter gets clogged up.

The Adblue system is entirely separate, and performs another function, so and has nothing to do with this.

If I were you I would get the sensor you removed / deleted reinstated. These have a purpose and removing them will cause other issues.

Thank you for your answer.

Ok, AdBlue is out of this, that's good.
Before the oil sensor deactivation, the car did the regenerate process in quiet, once a month, or twice, i didn't notice anything, just sometimes.
But now if i'm going for example a 30km "trip", engine is ok, after some kms, starting this process, then stops is, mirrors cooling down, and restarting again..Why?

My DPF is clean, car should't be start regeneration this quick times...within one trip without stop??

We had a code for bad fan assembly also, with "lack of coherence" maybe, something like this.

What can cause the problem? The fan's fault or the oil sensor deactivation?

Thanks!

[GiveMeABreak]

Ok, so if the vehicle cannot regenerate the filter because the conditions are not correct or complete a regeneration cycle because it has been interrupted, the Engine ECU will employ strategies to start the cycle again when conditions are favourable. So if the regeneration cycle is not completed (say when you switch off the engine) then the filter will remain blocked or partially blocked and the cycle repeats next time.

Having said that you particle filter may be actually blocked up and is having trouble regenerating. Anything over 70% blockage of the particle filter can prevent regeneration taking place as it becomes ineffective.

A brisk uninterrupted drive in 4th gear for 20-30 minutes, minimum 40 MPH should allow the exhaust gasses to reach temperature and allow a complete regeneration - but this is no good if the filter doesn't require a regeneration - so you should do this whenever you get the 'Particle Filter - Risk of Clogging' message.

[arielkiraly]

Ok, so if the vehicle cannot regenerate the filter because the conditions are not correct or complete a regeneration cycle because it has been interrupted, the Engine ECU will employ strategies to start the cycle again when conditions are favourable. So if the regeneration cycle is not completed (say when you switch off the engine) then the filter will remain blocked or partially blocked and the cycle repeats next time.

Having said that you particle filter may be actually blocked up and is having trouble regenerating. Anything over 70% blockage of the particle filter can prevent regeneration taking place as it becomes ineffective.

A brisk uninterrupted drive in 4th gear for 20-30 minutes, minimum 40 MPH should allow the exhaust gasses to reach temperature and allow a complete regeneration - but this is no good if the filter doesn't require a regeneration - so you should do this whenever you get the 'Particle Filter - Risk of Clogging' message.

Hmm, not sure if we are talking about the same stuff. Sorry, just want to clarify.

So we did check the datas with factory computer, and in the "brain" of the car, the DPF or particle filter, idk what is the proper name for it, is clean. Only maybe 15% dirt or less. The computer also said that there was a successfull regenerating/cleaning maybe 2500km before the check.

So based on the computer inside the car, the filter is clean, and was successfully cleaned before, but now something is running always and always, because my fuel consumption is at 8.4L/100 right now, or more...

If the regenerating process running, the computer should say that the car tried to regenerate it, but was not successfull, right?

I've never ever get this message from the car, that the "Particle Filter - Risk of Clogging", and never getting a fault light for particle filter, or anytihing like this. Only for the ADBlue's UREA light, Service light and Check engine light.

Can my problem base on the disabled oil sensor? It is the only thing i can think on.

IDK why but the engine needs more fuel for operate, and i can't find why. Tempreatures are OK, not low not high, oil pressure also OK, oil level is ok.

[GiveMeABreak]

No you will never get any such message about failed regeneration! The only message you will get is about the Particle filter additive level being too low, or the particle filter - risk of clogging.

Something else is going on and this is why it's NEVER a good idea to disable any sensors as often these are used as part of a complete system - and if this sensor is disabled it can impact the operation of the vehicle. Restore the sensor as it was. You don't need the hassle of extra fault finding because of a disabled sensor.

You should be able to read the average distance between regenerations to give you some idea of the frequency.
Also check the pressure differential sensors - are these reading normal?

If the vehicle is constantly trying to regenerate, then the engine ECU is getting data that is telling it the filter is blocked and to regenerate.

[arielkiraly]

No you will never get any such message about failed regeneration! The only message you will get is about the Particle filter additive level being too low, or the particle filter - risk of clogging.

Something else is going on and this is why it's NEVER a good idea to disable any sensors as often these are used as part of a complete system - and if this sensor is disabled it can impact the operation of the vehicle. Restore the sensor as it was. You don't need the hassle of extra fault finding because of a disabled sensor.

You should be able to read the average distance between regenerations to give you some idea of the frequency.
Also check the pressure differential sensors - are these reading normal?

If the vehicle is constantly trying to regenerate, then the engine ECU is getting data that is telling it the filter is blocked and to regenerate.

Quick update:

We did restore the sensor to it's original state, and then did a reset on the sensor. The fuel consumption is OK again, stable 5.7-6L/100
Since last thursday the error code not showed up again on the screen. Seems fine.

Is it possible that the sensor is OK physically, but needs a reset within X thousands of KM?

Ty btw every comment

[GiveMeABreak]

Not sure which sensor you are on about specifically, but most basic sensors can't be reset - they just do a specific job and there is nothing to reset, but they do have an impact on other systems which if disabled can cause operation problems. If other equipment relying on this data like the engine ECU starts getting incoherent or missing information then it can cause over or under compensation or backup modes to kick in which will affect vehicle performance and economy.