C5 3.0 HDi DPF Issues

[DHallworth]

Evening gents,

I'm having a few issues with our C5.

When we first got the car, under hard acceleration it would come up on the screen advising "Risk of DPF Clogging" and the service light would remain on for a minute. Robert at BL Auto's serviced the car and found that although the ECU thought it had 1.8 litres of EOLYS fluid in it, the tank was in fact empty so I'm guessing some kind soul had just turned the light off rather then filling the fluid before trading it in. After Robert filled the tank, I've had no issues with it in 18 months.

I was out in the car today, I went to Rutherglen from Langbank which is about 20 miles with no problems at all, then when I was about 4 miles into the journey home I got the BEEP, BEEP, BEEP, "Risk of particle filter clogging" message on the dashboard again. It then did the same thing a further 7 times on my journey home which was all motorway.

I got Diagbox out when I got home and had a look...

The clogging level is showing at 4%
There is 1.7 litres of aditive left in the tank
Total quantity of additive in the particle filter is 6g

Particle filter differential pressure when engine off is 0mbar, at idle it is was circa 9mbar, and with the car at 3200rpm is was showing at 95mbar.

These differential pressures seem a bit on the high side to me. I just wondered what other peoples thoughts were. The car has just ticked over 80k this week so it's not a particularly high mileage car.

Thanks,

David.

[RichardW]

Did it give any clue as to why it was putting the light on? Probably not.... light is on in our old C4 with no faults, I can only surmise that this is due to it having reached the limit of the additive in the DPF. What does it say about the last few regens, and the distance since the last regen?

95mbar at 3k unloaded does seem high. What do you get if you take it for a run and record the data - see what it says at 3k rpm under load.

6g of additive in the filter looks a bit suspect - unless it has been replaced (or someone has re-set the counter) - I would have expected around 80g at 80k.

You could do a forced regen and see where that takes it to.

[DHallworth]

I didn't see anything about the last regen or a distance since the last one. I'll take it for a good run this evening and see what lexia says once it's finished.

There was one error code stored, P1490.

David.

[GiveMeABreak]

There are 3 possibilities for those codes David:

• Differential exhaust pressure signal: Regeneration request too frequent
• Particle filter: Detected overloaded
• Secondary Air Relief Solenoid Circuit Malfunction

[DHallworth]

Interesting...

I'll try and get it out for a good run this evening and see what's happening.

What are the criteria that has to be met for the car to do a regen of the filter? Would 30 miles of motorway, around a roundabout, and then 30 miles back all at motorway speeds be enough?

David.

[GiveMeABreak]

More than adequate David, but unless you routinely do short journeys the regeneration should occur without having to do this within reason.

There are a number of scenarios where a regeneration can occur. The engine ECU can trigger this, depending on the last recorded journeys and whether regeneration was successful or not. Each failed regeneration will trigger a a secondary level regeneration and so on the next time round until at one stage where it cannot regenerate, it will bring up the warning light.

The most recent journeys and distance from last regen along with other data will determine this.

[DHallworth]

Thanks Marc.

It’s odd that it only started mucking around after a 20 mile trip.

It’s the first time in over a year I’ve seen the message and the journeys the car does hasn’t changed as far as I’m aware.

Will see what happens after a run tonight.

I’ve been looking into the warranty that’s on the car, it seems to be covered.

“Diesel particulate filter”
Diesel particulate filters are covered against their failure to regenerate following a specialist cleaning procedure which must be carried out first at your expense.

If this doesn’t work, I’ll look at getting it cleaned, failing that, the warranty company can sort it out.

David.

[DHallworth]

Right, I'm going to take it for a run, I've mapped a route which is all motorway with a minimum speed of 50mph, maximum 70mph that I don't actually need to come off the motorway for at all so that should give it the perfect chance to do a regeneration.

Will Lexia it when I get home and see what it's showing then!

Fingers crossed.

David.

[GiveMeABreak]

Good luck with that David, with all the excitement, don’t forget to turn round and come back!

[DHallworth]

I won’t

It’s a nuisance at the moment as I’m so short of time. Although there’s a warranty on the car, I hate claiming it as it always ends up being a headache when Citroen Glasgow process the claim.

David.

[Hell Razor5543]

The reason Citroen Glasgow make it a headache is that they have to pay out, in one way form or another. If they do it again I would seriously consider billing them for YOUR time, with copies going to Citroen UK.

[DHallworth]

It's not a Citroen UK warranty on it so there's no real cost to them, they're getting paid for the work they're doing.

Right, I've done 58 miles in it, 55 of which were very sedate, the last 3 I gave it a bit of abuse on the way home.

Differential pressure at idle is now showing 13mbar, at 3095 revs it's showing at 104mbar, so if anything, the pressures are higher then they were before. Those readings were straight after a drive.

Interestingly, I've not had a single warning from the car that there is a risk of the DPF clogging this evening.

My distance travelled since last regeneration is currently showing as 94km, the average distance for the last 5 regenerations is 509km. I'm not surprised the average over the last 5 is down as I've not used the car an awful lot.

David.