Have you taken it on a really good motorway blast? 25 miles there, 25 back, keep it in 5th instead of 6th.
You may have other issues going on, which may be causing the DPF to block, so need to investigate. Maybe one of the injectors has failed or similar?
Yes, garage took it for 26 mile run after forcing a regen and it was fine. I mentioned injectors to the garage and they said no way, you'd know if it was. Also no error codes. Plus the car is actually running very well. The garage even said it's a really nice example.
If your beloved is only doing short trips the DPf will block up ever so quickly, the engine/exhaust just doesnt get hot enough to get past the cold start/sooty stage.
I do understand the issues re short trips. However, the engine does get up to temperature quite quickly and whenever it decides to do a regen she lets it finish before turning off. I suspect in the long term we would be better off removing the dpf but I want to know what this issue is first.
It could be anything, get the workshop to force a regen and take a look.
It gets so hot it could be anything, like a fractured bracket for example.
They did a couple of forced regens and all was fine. It may be because when they did it they tested on the motorway whereas I think my wife was going slower when the regens have kicked in with the noise.
Re the fractured bracket, this is where my thinking is going. I thought "What happens during a regen?". All that happens is the car chucks a load more fuel into the DPF, which makes the exhaust get really hot (garage registered 700c!). That's it, nothing else.
Also, my wife said she thought it was coming from the rear of the car, which would rule out the DPF as that's at the front (although it's quite hard to tell where a noise is coming from while driving).
I'm now wondering if it's an exhaust bracket or even the baffles falling apart inside the silencer. Only thing is it ONLY does it while doing a regen. Would have thought baffles would make a noise all the time. Partially broken bracket may be possible though?