Smoking diesel DS3

[Lerxst]

Hi there.

I have a 2013 Diesel Ds3 that puts out a lot of dark smoke under acceleration, so much so that it mucked up my guy's brand new MOT emissions machine. When it starts it puts out a puff of white smoke. Both these symptoms started after I had the DPF changed due to the 'risk of clogging' and beep alert I was getting. This is a summary of what the garage did last time I was there attempting to fix the problem:

'When the car first came into us the technician’s carried out tests on the EGR and found that the original one was faulty. So, they replaced the EGR for a new one. This brought down the emissions slightly but not enough to pass the mot.
They then tested an airflow meter, but this did nothing to the car to rectify the issue so was then taken off – Customer not charged for this.
Then they tested all the injectors on the car and all the findings from this came back all fine. The next test was a fuel quality check with the findings for this all came back fine.
Then the technicians plugged the car into the diagnostics system to check the cars ECU system and did a vehicle engine download, to bring the cars engine software up to date.
Because they could not find the route cause of the emissions fault, after trying many routes. And for the car to be able to pass the mot they then did a regeneration process on the vehicle for it to get through the emissions test on the mot.'

The DPF they used was a cheaper version and in other visits there were other faults I had fixed such as the trailer lighting and the heater and as a result of their efforts, which I won't bore you with, I've come to the conclusion that they are basically incompetent and I'm currently looking for a new place, I really don't want to go back there for an argument then let them loose on it again.

Are these cheap DPFs basically garbage? Any idea what I should direct the next garage to look at? Thanks.

[GiveMeABreak]

There shouldn't be any thick dark smoke coming out of the exhaust, if it is, it can be a sign of over-fuelling.

Yes the EGR can contribute to this - and again, parts quality is essential. Cheap parts won't have the same quality or can even be faulty. The same with a DPF. These are expensive because of the materials used and are generally designed to last for a good 100- 150k miles.

So I would focus on the fuelling and I'm concerned that the garage found it necessary to 'update' your engine ECU without good reason or an explanation. Even Citroen only tend do this when necessary or if there is a specific fault.

The inlet manifold can be another source of deposits that can affect performance if these get gunked up with carbon. But there is definitely a fuelling issue indicated as lack of oxygen will cause too rich a mixture and black smoke. Check the air filter and replace if necessary.

The MAF should be cleaned or replaced if you suspect this, but generally this will provide a fault code if faulty or out of range.

Some vehicles also need the engine ECU to be told that certain parts have been replaced and may have a learning procedure like the EGR. Pop your VIN up and I'll be able to advise. Likewise with the DPF. The engine ECU must be told this has been replaced.

I would advise getting the actual fault codes that were picked up - or get a diagnostic done with Diagbox and put them up here as without fault codes it will be difficult to point you in the right direction.

Have a look at Elis's post and videos here concerning this:

viewtopic.php?p=583334#p583334

[Lerxst]

Hi, thanks for the reply.

The chassis number, I'm presuming that is the VIN, is VF7**************[VIN obfuscated, can be read by forum staff]. How would I get a 'Diagbox' readout, is this something every garage has or is it just something like Carly and my phone?

Thanks.

[GiveMeABreak]

Ok, so confirmed that the EGR does need initialising after being replaced.

Diagbox is the Citroen diagnostic software used by the dealers. You will need a professional level diagnostic tool and software to perform anything other than reading codes. I would of expected the people who replaced your EGR valve to know this and initialise it - but then again...

[cit-rotti]

Carly and similar diagnostic tools can be good helpers in finding errors.
However, such diagnostic devices only recognise a part of the installed ECUs and many additional options (component tests/parameter measurements/initialisation processes etc.) are not possible.
Only with the PSA software/hardware (DIAGBOX/LEXIA/PLANET) is almost everything possible except for ECU updates.

Greetings Wolfgang

[liquidhandwash]

I repaired an hdi 406 with the same issue, rolling coal, it was a split hose between the intercooler and the engine, that only leaked under boost fine at light acceleration.

[Lerxst]

I would advise getting the actual fault codes that were picked up - or get a diagnostic done with Diagbox and put them up here as without fault codes it will be difficult to point you in the right direction.

I'll have these up as soon as I can get it organised.

[Lerxst]

I repaired an hdi 406 with the same issue, rolling coal, it was a split hose between the intercooler and the engine, that only leaked under boost fine at light acceleration.

I'll check that out too, thanks.

[Lerxst]

Diag Box results

[GiveMeABreak]

Unfortunately none of those codes are coming for your vehicle. That's an aftermarket diagnostic tool too, so maybe why.

[Lerxst]

Ok thanks, I have another place to try, I'll be back...

[Lerxst]

Air filter replaced 9 months ago 35,000 miles