Citroen ds3 failed emission checked air filter puffing out black smoke

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mitch886
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Citroen ds3 failed emission checked air filter puffing out black smoke

Post by mitch886 »

hi can u help my 2012 34k Citroen 1.6 hdi has failed emissions on mot. 1.34 when limit 0.51, it’s puffing out black smoke but runs fine, no warnings on dash. checked air filter but was replaced 2 months ago. as was oil change and added red ex. any idea
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GiveMeABreak
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by GiveMeABreak »

Pop your VIN up (automasked on post submission)so we can see what type of engine you have and other specifics. It will save me asking loads of other questions.
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xantia_v6
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by xantia_v6 »

One question that does need to be asked is: Under what running conditions to it puff out black smoke?
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Paul-R
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by Paul-R »

mitch886 wrote:
23 Jul 2022, 18:45
...added red ex. any idea
How much RedEx? With how much fuel? Was it specifically for diesel engines? - PSA recommend that additives are NOT added to diesel fuel.
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Rp0thejester
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by Rp0thejester »

I've added Redex many times to my C8 diesel, and always at half a tank, no issues found imo. If anything it's helped me with my dpf situation until I refilled the dpf fluid
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myglaren
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by myglaren »

I tried some in my C5 and it didn't make a blind bit of difference.
MattBLancs
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by MattBLancs »

EGR stuck open? (Would think likely through a code though)

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mitch886
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by mitch886 »

VIN number VF7**************[VIN obfuscated, can be read by forum staff]
mitch886
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by mitch886 »

it puffs black smoke when pushing foot on throttle, have take for a long run and no warning of risk of clogging which i’ve had before, redex i added half the bottle to half a tank of fuel as per instructions. like i said car runs fine just black smoke hence high emissions and mot fail
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GiveMeABreak
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by GiveMeABreak »

Ok, so you have a 1.6 HDi 92 (DV6DTED) vehicle and this one does have a DPF fitted.

Black smoke should not happen at all with a DPF-equipped vehicle unless it is getting blocked and has not been able to regenerate, but you would of had some warnings displayed on the dash about this. I'm assuming you know the history of the vehicle and that the DPF has not been tampered with or removed?

So next, incorrect air / fuel mixture leading to over-fuelling can also cause black smoke. Has the engine been 'tuned or remapped'?

If an Italian tune up does not clear the issue, then it needs a diagnostic to see if there are any fault codes being returned / and check the status of DPF regeneration / distance before regenerations info from the engine ECU.
mitch886
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by mitch886 »

thankyou for your reply. yes i know the history of the car i am the second owner after my mum that bought the car from new. there hasn’t been any tuning or tampering with the dpf. it passed the mot last year without any probs on emissions. i do not drive it far each day maybe 6-10 miles a day. i have in the past had “risk of clogging” warning appear on dash but a good blast up the motorway usually clears this warning. but not had any warning since which is strange. i will now take it to the garage and have it put on diagnostics. hopefully get some answers then
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GiveMeABreak
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by GiveMeABreak »

Ok, so it's likely to be the short journeys issue then. Not generally good for diesels, even with assisted regeneration, as the exhaust gasses still need to reach 450 °C for regeneration to start as opposed to 550 °C.

I suspect the engine ECU has attempted multiple regeneration operations, but has failed to start or complete a cycle with such short journeys as 6-10 miles is barely enough to warm the engine up and I'm assuming that 6-10 miles is also a 'there and back' journey, so even worse.

I suspect your DPF is clogged. Try going for a reasonable long run, of at least 40 MPH and keep it in 4th gear to increase engine revs to help raise the temperature a lot quicker. Go for a good 40 minutes drive and if possible where legal get it up to 60 for a good run. That in combination with a suitable diesel fuel cleaner to give the injection system a good clean may solve your issue.

Before the MOT retest give it another good run and hopefully that may nail it.
mitch886
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by mitch886 »

i took the car for a 30 min run yesterday. obviously cant really go to far as no MOT kept the revs above 2.5k and it was really hot when i got home i suspected the same as u a clogged DPF just don’t get why no warning tho. i will take ur advice and get checked for any codes and maybe will have to remove and unclog DPF. thanx for ur replies
mitch886
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Re: Citroen ds3 failed emission checked air filter puffing out black smoke

Post by mitch886 »

update on cirtroen ds3 black smoke. took car to friends garage and plugged into diagnostics. found intermittent fault with turbo. (not got code) cleared code and having turbo and pipes looked at tomz. still no warnings and or engine management light on. did a emissions test and passed at 1.5limit. 1.22 average but car was tested at previous garage for MOT at 0.51 limit. but car passed emissions test at 0.51 limit last year at same garage. so a little puzzled. as it’s now average 1.22 (3 times as much) is the turbo associated with the egr valve? causing black smoke.