C5 III repeated particulate filter warning

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Richard_C
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C5 III repeated particulate filter warning

Post by Richard_C »

2.0Hdi 163 manual. 2 years old 28k miles

Got the car in September, with 20k miles on it. On first long trip it 'bing bonged' the particulate filter may become blocked warning. As it happens I was just pulling on to the M4 and after 10 miles or so "at speed" it cleared. Never came back, until last Friday.

Had it serviced 2 weeks ago.

I had spent 2 weeks pootling about locally, it bing bonged and I thought no problem, 10 miles up a dual carriageway using 3rd & 4th to get a decent airflow, fine next time I started it.

Next day, it did its warning stuff just after I set off from home, 20 miles up the M11, didn't clear but when I next restarted it was fine.

Sunday, same again but I was on a B road trip, it cleared itself and the service light went out after a few miles.

Today, on way to station, country roads c 50 mph and 5 miles, bing bong, on way home, the same.

So - what's going on? Choice seems to be a good long trip (but no real need to do one for a couple of weeks) or back to servicing dealer. Grrrrrrrrrr.
Richard_C

Current: , C4 Picasso 120 BlueHdi, C3 1.2 Auto
Past Citroens: Dyane (x2), 2CV, Visa, BX (x2), Xantia, Xsara Picasso, C3 (x2) C5 X7 Tourer, Synergie 1.9TD, C1
Others: Hillman Hunter, Cortina Mk 1, Maxi, VW Type 2, Granada, SAAB 900, SAAB 9-5, R5 Gordini
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SaabC5
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Re: C5 III repeated particulate filter warning

Post by SaabC5 »

It needs a proper long run to burn off the carbon deposits, i'm hazarding a guess that the 20-30 mile runs are starting the regeneration process but it never finishes the job, the short trips are then gunking up the DPF hence the warning light. I try to do at least a 100 mile trip once a month just to burn out the deposits and the car always feels better for it afterwards. Short town stop/start journeys are not good news for diesel cars fitted with diesel particulate filters.
09 C5 X7 2.0Hdi Exclusive in Perla Nera black (the best colour) :wink:
Richard_C
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Re: C5 III repeated particulate filter warning

Post by Richard_C »

I was coming to that conclusion. I usually do a good long trip at least weekly, sometimes even have a 600 mile day. But recently work and other committments have meant local trips only. I will fit in a 100+ somehow before I go back to dealer. Co-incidentally it was same time as the hot weather and using aircon all the time, but I think you are right and a long trip is required.

So - to regenerate is it just about keeping the filter hot for long enough or does it need some "throughput" of hot gasses? At 70 the engine is only at 2000 rpm in 6th - would it regenerate quicker/better at higher rpm? I've not really investigated how these eolys things work. My old synergie needs a few miles at 4500 rpm to blow the s_it out every so often, especially before MOTs but that has no filter being an ancient XUD.

Does anyone know of a good explanation (anywhere on the web) of how DPFs and eolys systems work?
Richard_C

Current: , C4 Picasso 120 BlueHdi, C3 1.2 Auto
Past Citroens: Dyane (x2), 2CV, Visa, BX (x2), Xantia, Xsara Picasso, C3 (x2) C5 X7 Tourer, Synergie 1.9TD, C1
Others: Hillman Hunter, Cortina Mk 1, Maxi, VW Type 2, Granada, SAAB 900, SAAB 9-5, R5 Gordini
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SaabC5
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Re: C5 III repeated particulate filter warning

Post by SaabC5 »

Found this on the C4 owners website if the mods will allow the link....

http://c4owners.org/plugins/faq/faq.php?0.cat.10.44
09 C5 X7 2.0Hdi Exclusive in Perla Nera black (the best colour) :wink:
steelcityuk
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Re: C5 III repeated particulate filter warning

Post by steelcityuk »

I read a interesting piece on another forum about regen of DPFs. An 'expert' on that site asserted that the best and most efficient way of doing it was to load up the engine at low revs, this he claims will increase the exhaust gas temperature to near maximum completing the regen more quickly and using less fuel. Another had tried what was suggested and had seen a reduction in regen time.

Steve.
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Richard_C
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Re: C5 III repeated particulate filter warning

Post by Richard_C »

Indeed, based on my empirical test.

Intuitively you would want to push loads of air through the system, so a blast in a lower gear would be the thing to do. That is what I had been trying, to no avail.

I then did about 10 miles on A roads in mixed traffic. Travelled at 40-60 in 5th and 6th and using the torque -around 1200 - 2200 rpm. Lo and behold the service light cleared quickly and has stayed clear.

Thanks all.
Richard_C

Current: , C4 Picasso 120 BlueHdi, C3 1.2 Auto
Past Citroens: Dyane (x2), 2CV, Visa, BX (x2), Xantia, Xsara Picasso, C3 (x2) C5 X7 Tourer, Synergie 1.9TD, C1
Others: Hillman Hunter, Cortina Mk 1, Maxi, VW Type 2, Granada, SAAB 900, SAAB 9-5, R5 Gordini
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