More DPF problems

Coolcity · May 13, 2022

I recently got the amber "DPF Full" warning on the dash. I thought this was a bit odd at the time as a few days earlier we did a 'country lane' drive of a total of 140 miles, so not motorway speeds but pretty much non-stop quick driving apart from a break along the way. So if it was on its way to becoming full that should have cleared it.

After that I probably did around 10-15 miles local stop-start driving over the next week which is about average for the week.

The warning actually came on after the car had been idling for about 5 minutes as I was waiting for the missus in a car park and wanted the heaters on.

Anyway, the next day we did a 45 mile motorway drive, driving back via the A roads at 40-50 mph, again quiet roads, non-stop driving, and the warning cleared. I didn't notice at what point it cleared.

Similar routine followed, around 10 miles or so (in total) short trip driving around town for the next few days, and the warning came back on again.

I then did another 60 mile motorway round trip at between 60-70 mph but this time the warning hasn't cleared.

Anybody know why this could be happening? Last October I had the DPF filter removed and cleaned completely after a similar problem, although in that case the RED DPF full warning kept coming on when I accelerated hard, and it was noticably more sluggish to drive then than it is at the moment. I'd only had car a short time at that point but suspect it had only been used for short trips before I got it due to the low mileage, which was probably why the DPF was clogged up. But I have only done around 2500 miles since that job was done. I do a few short journeys of a mile or so maybe 3-4 times a week but do motorway runs in between of 40-50 miles or so to try to keep it clear. The car should be able to cope with that, surely? I know people with diesels who only do the school run and shopping every day who never have a problem, and the car has only done 56k.

Could it be a faulty sensor or the regen system not kicking in when it should be? (I haven't noticed the burning Oil smell recently that you get when the system is regenerating).

Car seems to drive perfectly fine, no loss of power or anything. I do have it booked in but can't get it looked at until a week Thursday.

Coolcity · May 14, 2022

Quick update. I've just done a diag using the iCarsoft LR v2 and the only fault code I got was P2458 - DPF Regeneration Duration. But it doesn't give any figures on what that duration is.

There are no other codes and no other symptoms, the car appears to run as normal and the Oil level hasn't changed, it's at around 75%.

I decided to set it up for a forced regen to get the soot figure, which makes interesting reading. It measured at 3329.08 grams. That's a huge figure given that the system won't do a forced regen if the level is over 60 grams. Obviously there's a vast difference between 3329 and 60 grams and that high a level would surely cause serious problems?

Does this suggest a faulty sensor or something of that nature? Bearing in mind I've only done around 2500 miles in the 7-8 months since the DPF was removed and cleaned, around 20-25% of that would have been town driving, the rest either motorway or fast A-road with most of that being in the past few months (we haven't really been anywhere between November-March as the wife was recovering from an op).

Makes no sense at all to me that the DPF would be blocked given the overall type of use over the past few months, especially recent months.

One other slight oddity. I did the same scan last week and have only driven 2 miles since. I checked the "Distance to next service", just out of curiosity, and last week it read 7578Km. This week it reads 3541Km.