Dreaded black smoke

[EthelredS]

That’s interesting - but no all original

[CitROeNALD]

Yep, it's the kind of thing that goes undetected, no codes or anything. But it stops the DPF being maintained as one of the parameters the computer needs is outside air temp.

So if it is non-functional, the DPF can block up pretty quick and no indication why.

But, it sounds like yours is operating correctly.

[Rp0thejester]

I'm now thinking sensors after the dpf

[shtu]

I'd be tempted to get the injectors pulled and tested. Done at a diesel specialist rather than a dealer, this isn't especially expensive.

I'm wondering if the no4 contribution fault could be due to a problem with no1, the managent trying to compensate, and running out of ability to. If you have diagnostics kit, you may be able to spot a wide variation in correction values across the 4. It's possible to swap them about, recode, and see if the fautl follows one particular injector, but if you're paying to have that done it's cheaper to just pull the lot and test on a proper injector tester.

Ultimately, loads of black smoke = there's a lot of fuel going in.

[EthelredS]

Regarding having the injectors tested - I keep coming back to a comment the guy at the garage made about not testing injectors anymore as they almost always come back faulty and need replacing. The Citroen dealer told me they deteriorate with age as well as mileage. We were booked in to have the remaining three done with our local garage. In the meantime he’d been talking to some diesel experts and one suggested if there was sooty black smoke it was a faulty dpf, even a hairline crack that wouldn’t be seen on inspection, which is why we had it replaced instead of the injectors. Hoping this time there’ll be a code - non so far, or warning lights on the dash. (Wish we’d kept our old Volvo)

[RichardW]

If it's smoking the DPF is broken.

Yes, it was a copy part - trying to keep costs down.

Is probably [part of] the issue - aftermarket parts are pretty junk. You would be better off getting a used one of low mileage crashed unit. It may be that there is some underlying cause that is causing the DPF to overheat and failing it - these are normally pretty reliable, so would need to figure out why the original one failed.

[Tony1969]

I have a similar issue, still in the process of fixing, I am suspicious of my fuel temp reading reading -60. My theory was if the van thinks it’s in the arctic then it’s going to throw the fuel in.
I’d be surprised if a dip was the cause of yours, it just stores soot to burn later. I’m guessing your new one just filtered it out until it was as full as your old one.

[Rp0thejester]

Just out of curiosity, has your eolys level been checked recently? If not the dpf will block quickly. As for outside temperature, it will determine when the dpf regenerates naturally as it needs to reach a certain temperature.

[EthelredS]

No it hasn’t so thanks for that. I’ll get it checked on Tuesday when it goes in. We haven’t had the warning light for it so I’ve assumed it’s OK,

[Rp0thejester]

Unfortunately I wouldn't know if a warning light would come on if it was low because my car is computer screened and guesses when it needs to be filled up.

[EthelredS]

Well, we’ve got another dpf fitted with the previous one being returned under warranty. All scans and readings show everything working as it should. Time will tell. Thanks everyone for your comments - I hope I shan’t be back here again!

[Rp0thejester]

Fingers crossed because your sooooo boooorrrring.....

[EthelredS]

The saga has been rumbling on all through the summer. Went in today to fuel injector specialist. All three remaining injectors faulty causing the replacement dpf to fail. Full new set of injectors being fitted and good quality dpf. Still can’t grasp the fact we’ve had this issue for so long without any codes or dashboard messages. Should have listened to Citroen in the beginning - hey ho.