DPF Regen-What does it feel like?

[andy8442]

What should I expect to feel when the DPF does a regen?

I ask this as I had a hellish experience with a VW T5 a few years ago (a whole other story!) but after 6K of driving my new D3 I still don't think I've noticed the car doing a regen.

I do a lot of motorway driving and assume the regen is happening then, but it would be nice to know what to expect, so as not to confuse it with something un-toward.

[clivea]

Mine is a MY2010 D5 with nearly 40k on the clock and to be honest I have never been aware of it regenerating. I would have liked a dash indicator so that I didn't switch off part way through. But I now "trust" as I've had no increase in oil levels or any untoward DPF effects. But for my first year I had sleepless nights over DPF and no easily accessible oil dip stick!!

[tt82]

The DPF only needs to regenerate if the filter becomes blocked with soot. Every time the car is used, when the dpf reaches operating temperature it will start to burn off all the soot naturally. This means if your doing enough miles for the exhaust and dpf to get to temp it will never regenerate.

[Clan]

Originally Posted by tt82

The DPF only needs to regenerate if the filter becomes blocked with soot. Every time the car is used, when the dpf reaches operating temperature it will start to burn off all the soot naturally. This means if your doing enough miles for the exhaust and dpf to get to temp it will never regenerate.

A diesel doesnt get hot enough to self regenerate the exhaust runs at around 200-300 C normaly depending on load . A regeneration requires 600C to burn out the accumulated soot . This happens roughly once a tank full of fuel .

[tt82]

Bliney, I stand corrected. I was under the impression that regular use was sufficient to clear it. Thanks clan for clearing that up.

[Clan]

Originally Posted by tt82

Bliney, I stand corrected. I was under the impression that regular use was sufficient to clear it. Thanks clan for clearing that up.

yes regular use is all that is required , if necessary it will regenerate plodding along at 60 mph , it will inject fuel after the power stroke which will burn in the Particle filter at 600 C and burn off the soot ...

[I-S]

A couple of times I've noticed a sudden drop in instantaneous mpg which I suspect to be a regen cycle. Car did not drive differently. It seems to occur after a mile-long hill climb on my commute (from waterhead up to austerlands, tt82 will know the hill I mean). That load seems to trigger the regen, but then I go down the other side of the hill with no throttle and by the time I get to the bottom it's back to normal mpg (I think if it's still doing regen down the hill, the amount of fuel used is not enough to reduce the fuel economy below the 99.9 that the computer can show).

[volvorocks]

A regen often goes unnoticed. Perhaps sometimes if you are getting shocking mpg on the trip, then it may be doing a regen. Sometimes I have noticed that the 99.9 mpg on the trip is never reached when coasting which may indicate a regen?

When I have noticed this, I also notice a drop in performance/acceleration/power. This drop is not evident under normal driving/cruising although if you call on the acceleration there is a distinct drop.

Regards

[CJL]

Same here. All I've noticed is a drop in fuel economy.

[St Evelyn]

If you look in the My Car menu whilst driving and go through to stop/start, it will always show up as 'engine system' preventing stop/start from working when the DPF is regenerating. You should note though, that this message can also come up due to other causes.

Originally Posted by Clan

This happens roughly once a tank full of fuel .

Sadly in my case, for the last 2 months this comes up every other day, along with an associated significant drop in economy; I only ever use Shell diesel in my S80 D3 and drive about 750 miles a work for my daily commute, meaning that I fill up pretty much once every week so it would appear to be happening 2-3 times as frequently as it ought to. Strange that it used to be once a week to once a fortnight prior to the summer though...

In addition, since my latest service a couple of weeks ago, I now get the 'electrical system' preventing stop-start every single day - getting really exasperated with the stop-start system now. MRG tell me that if the battery goes below a certain level (73% full I think they said) then this will cause this message - it all seems a bit strange to me that over 35K miles I saw this message twice, then I've seen it every day since my last service less than 2K miles ago. I do wonder whether the latest software update has tweaked some settings, causing this error.