DPF Regeneration Too Regular

[acarty]

Afternoon All,

Maybe a bit of a strange one this as I know DPF issues are usually associated with it not regenerating and as a result it becomes blocked. Searched all over the internet but I couldn't find much apart from one other case.

I've noticed over the past few months that the DPF is regenerating too regularly. It used to be approx. every 300 miles, but this has now reduced to almost less than every 50 miles. Every few days (sometimes daily) I can notice the engine note change with it holding the revs higher and when I check with carly, it shows a regeneration is occurring. Had it into a garage who replaced the water pump stat and forced a regen, but I think they mis-interpreted the issue of it regenerating too regularly.

Ash mass is around 23g and has stayed constant (going up very slightly) so I'm assuming that the DPF is OK (this goes up to around 40g?). Its the soot mass which rises from 0g to 30g over only a few miles and so requests a regen. Assuming each regen is properly burning off the soot mass, what would cause excessive soot mass to build up?

I put Shell oil in as opposed to Castrol for the first time in April (now BMW's preferred choice?) but it was DPF friendly so I'm not convinced its that? I noticed on carly the 'produced soot mass per time' parameter is regularly flicking from what seems to be steady values of <1mg/s to a value of 655.35mg/s. Is this a faulty reading since it is so specific each time? Sensor related?

Sorry for the long post and thanks in advance,
Andy.