DS5 DPF pressure readings, informed opinion requested..

[andyandjulie]

Hi everyone

I had problems with a blocked DPF back in late November last year and had it chemically cleaned. I bought a Diagnostic Tool after Christmas and have been checking the DPF pressure every week.

What do you think of my readings over about 3000 miles pasted below?

DATE RPM BAR

16.03.25 3466 0.09
16.03.25 748 0.01
09.03.25 3676 0.11
09.03.25 748 0.01
03.03.25 810 0.01
03.03.25 3671 0.11
24.02.25 3664 0.09
24.02.25 751 0.09
17.02.25 3663 0.12
10.02.25 2585 0.05
10.02.25 2798 0.08
10.02.25 811 0.01
03.02.25 3657 0.08
03.02.25 748 0.01
03.02.25 751 0.08
28.01.25 3682 0.08
28.01.25 745 0.01
20.01.25 3635 0.04
19.01.25 809 0.01

The car is running well ever since. I still don't know what caused the initial problem, the car went into limp mode and had numerous dashboard warnings, but I'd love to know. Anybody have an idea?

Thanks in advance.

I've just previewed this and apologies for the splattered formatting..

Andy

[GiveMeABreak]

This really doesn't tell you anything as the DPF pressure rises and falls:- rises as the filter becomes blocked, regenerates and then pressure falls again.

This will vary according to driving conditions.

[andyandjulie]

Hi Marc

That's what I'm asking about. Can you see that happening from these figures? Is this a healthy set of results for a car with 25K Miles. There is a slow increase to my mind. I will continue taking readings, but these results over 3 months must be an insight into the DPF workings surely..

Andy

[PaulC5]

You could look at the distance between regenerations, that might give you a better idea if it is blocking up at shorter distances.

[RichardW]

It doesn't look too bad, around 10 mbar at idle, touching 100 mbar at 3500 rpm - that might be a touch high, but if you've done 3000 miles and it's not complaining don't worry about it. Generally they only block up if something else is wrong which inhibits regen - unless you do a lot of short runs. As Paul says check the regen cycle - if possible work out when it is going to regen and then catch the figures immediately after - you are looking for <10 mbar at idle and 50-60 at 3k rpm. Is this a Euro 5 or 6 engine?

[GiveMeABreak]

This is a Euro 6.2 Richard.

[andyandjulie]

You could look at the distance between regenerations, that might give you a better idea if it is blocking up at shorter distances.

That's something I'd heard about, thanks Paul. I'm a novice with my diagnostic tool, but I'll look into it.

Andy

[andyandjulie]

It doesn't look too bad, around 10 mbar at idle, touching 100 mbar at 3500 rpm - that might be a touch high, but if you've done 3000 miles and it's not complaining don't worry about it. Generally they only block up if something else is wrong which inhibits regen - unless you do a lot of short runs. As Paul says check the regen cycle - if possible work out when it is going to regen and then catch the figures immediately after - you are looking for <10 mbar at idle and 50-60 at 3k rpm. Is this a Euro 5 or 6 engine?

Thanks Richard, Sage advice I think. I'm still not convinced that the car is actively regenerating.. I'm going to install the tell-tale LED that "tricoloured" suggested a little while back. It iluminates when the heated mirrors are switched on as an indication of an active regeneration. I've found my glue gun.