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[Sir Tigger KC]

Remember also that if a petrol car is chucking out un-burnt fuel then the cat will be dead pretty quickly, his will then fail the test even of the Lambda figure is met.

Interestingly, I got a print out two weeks ago when the bus passed its MOT which showed the particulate levels at differing engine revs which was a surprise (it passed easily as it does have a fitted and working DPF - 185k miles and no issues)

At these kind of miles, do you begin to have issues with ash? As I understand it the soot is burned off in the re-gen process, leaving just ash.

VAGCOM tells me there is 34g of ash in my DPF and it can hold 75g, currently on 83k miles. But suggests 160k+ it could be approaching full, at that point can you remove the DPF to get rid of the cash?

Yes removing the DPF will get rid of your cash, which is the whole point of this thread Tunnie!     

[Marks DTM Calib]

Remember also that if a petrol car is chucking out un-burnt fuel then the cat will be dead pretty quickly, his will then fail the test even of the Lambda figure is met.

Interestingly, I got a print out two weeks ago when the bus passed its MOT which showed the particulate levels at differing engine revs which was a surprise (it passed easily as it does have a fitted and working DPF - 185k miles and no issues)

At these kind of miles, do you begin to have issues with ash? As I understand it the soot is burned off in the re-gen process, leaving just ash.

VAGCOM tells me there is 34g of ash in my DPF and it can hold 75g, currently on 83k miles. But suggests 160k+ it could be approaching full, at that point can you remove the DPF to get rid of the cash?

Its about 85% full and you can get them emptied, the main cause of the ash is actually the oil burning as part of the combustion cycle so regular oil changes with the correct oil helps.

That's said I seem to recall the VW removal procedure starting off something like, 1) Remove subframe....

[tunnie]

Remember also that if a petrol car is chucking out un-burnt fuel then the cat will be dead pretty quickly, his will then fail the test even of the Lambda figure is met.

Interestingly, I got a print out two weeks ago when the bus passed its MOT which showed the particulate levels at differing engine revs which was a surprise (it passed easily as it does have a fitted and working DPF - 185k miles and no issues)

At these kind of miles, do you begin to have issues with ash? As I understand it the soot is burned off in the re-gen process, leaving just ash.

VAGCOM tells me there is 34g of ash in my DPF and it can hold 75g, currently on 83k miles. But suggests 160k+ it could be approaching full, at that point can you remove the DPF to get rid of the cash?

Yes removing the DPF will get rid of your cash, which is the whole point of this thread Tunnie!     

Oops an interesting an unfortunate typo!     

Remember also that if a petrol car is chucking out un-burnt fuel then the cat will be dead pretty quickly, his will then fail the test even of the Lambda figure is met.

Interestingly, I got a print out two weeks ago when the bus passed its MOT which showed the particulate levels at differing engine revs which was a surprise (it passed easily as it does have a fitted and working DPF - 185k miles and no issues)

At these kind of miles, do you begin to have issues with ash? As I understand it the soot is burned off in the re-gen process, leaving just ash.

VAGCOM tells me there is 34g of ash in my DPF and it can hold 75g, currently on 83k miles. But suggests 160k+ it could be approaching full, at that point can you remove the DPF to get rid of the cash?

Its about 85% full and you can get them emptied, the main cause of the ash is actually the oil burning as part of the combustion cycle so regular oil changes with the correct oil helps.

That's said I seem to recall the VW removal procedure starting off something like, 1) Remove subframe....

Thanks. Looking at history it's dealer service so oil changes every 17k.

I'll look to bring this down to every sub 10k by doing it myself, so I would guess this would slow the rate of ash build up.

I know how you like VW  - I know even more you would love to help a useless student strip down the inlet for cleaning, so I know more about this dirty diesel   

[Doctor Gollum]

The regenerative burns the ash off...

[Marks DTM Calib]

The regenerative burns the ash off...

Sadly not, the regen burns the trapped soot particulates but, you get left with a small amount of ash which remains trapped in the DPF and slowly builds up over time until they are fully clogged.

Most of the ash is a result of tiny amounts of oil getting trapped rather than from the diesel combustion.

There are a firms who will take a DPF and reverse flush the ash out (its been a common thing on lorries for some time)

[Doctor Gollum]

Ah ok... Thought the principle was to get the whole thing hot enough to produce such fine ash that it was blown out as a matter of course

Not that either result is particularly good to breathe in...

[Viral_Jim]

At these kind of miles, do you begin to have issues with ash? As I understand it the soot is burned off in the re-gen process, leaving just ash.

VAGCOM tells me there is 34g of ash in my DPF and it can hold 75g, currently on 83k miles. But suggests 160k+ it could be approaching full, at that point can you remove the DPF to get rid of the cash?

Freudian slip? 

In all seriousness I've seen companies offering services for either high pressure air cleaning and ultrasonic. Not sure which is best, as I never intended to have a dpf car and keep the dpf in it (lucky i didn't go down that route or I'd be in schtuck come next year). Ahat I would say is maybe get it done before its "full" - probably easier to clean. That's just a guess though.

The bottom line on DPF's is they work fine when used in the correct application (as you are discovering) but people bought diesels for the wrong application and frequently pay the price. Maintaining something every 160k could hardly be described as a chore .

Ah ok... Thought the principle was to get the whole thing hot enough to produce such fine ash that it was blown out as a matter of course

That is indeed the idea, but its not 100% removed. However, as tunnie's experience is showing, a build-up of 0.41g per 1000 miles driven, is a pretty slow rate of accretion.

[tunnie]

At these kind of miles, do you begin to have issues with ash? As I understand it the soot is burned off in the re-gen process, leaving just ash.

VAGCOM tells me there is 34g of ash in my DPF and it can hold 75g, currently on 83k miles. But suggests 160k+ it could be approaching full, at that point can you remove the DPF to get rid of the cash?

Freudian slip? 

In all seriousness I've seen companies offering services for either high pressure air cleaning and ultrasonic. Not sure which is best, as I never intended to have a dpf car and keep the dpf in it (lucky i didn't go down that route or I'd be in schtuck come next year). Ahat I would say is maybe get it done before its "full" - probably easier to clean. That's just a guess though.

The bottom line on DPF's is they work fine when used in the correct application (as you are discovering) but people bought diesels for the wrong application and frequently pay the price. Maintaining something every 160k could hardly be described as a chore .

Ah ok... Thought the principle was to get the whole thing hot enough to produce such fine ash that it was blown out as a matter of course

That is indeed the idea, but its not 100% removed. However, as tunnie's experience is showing, a build-up of 0.41g per 1000 miles driven, is a pretty slow rate of accretion.

Yes, I have noticed that the re-gens only occur on my way back from work. In the heat yesterday on the way home I felt it took longer on a cycle. The way I can tell is idle is 1 bar higher on the needle compared to normal, took about 30 mins to do a cycle yesterday.

Hence I can see diesel working for anyone with a commute of at least 40 mins, or like TD the car engine is on all day in taxi work doing an idle-based re-gen. But it means diesel with DPF is not suitable for the wife, with her town only miles.

If I still have the VW at 160/70/80k I don't see it being an issue getting it removed and cleaned.

[Marks DTM Calib]

Thanks. Looking at history it's dealer service so oil changes every 17k.

I'll look to bring this down to every sub 10k by doing it myself, so I would guess this would slow the rate of ash build up.

I know how you like VW  - I know even more you would love to help a useless student strip down the inlet for cleaning, so I know more about this dirty diesel   

Oh I love cleaning diesel inlet manifolds, its such a pleasant and rewarding job

My issue with the VW diesel is that dam 2.0 engine, an utter mare compared to the joy of the PD

Dark was that day when Diesel conceived his grim engine that begot you, vile invention, more vicious, more criminal than the camera even, metallic monstrosity, bale and bane of our culture, chief woe of our Commonweal. How dare the Law prohibit hashish and heroin yet license your use, who inflate all weak inferior egos? Their addicts only do harm to their own lives: you poison the lungs of the innocent, your din dithers the peaceful, and on choked roads hundreds must daily die by chance-medley. Nimble technicians, surely you should hang your heads in shame. Your wit works mighty wonders, has landed men on the Moon, replaced brains by computers, and can smithy a "smart" bomb. It is a crying scandal that you cannot take the time or be bothered to build us, what sanity knows we need, an odorless and noiseless staid little electric brougham.

W.H. Auden (1907-1973), A Curse:

[Marks DTM Calib]

Ah ok... Thought the principle was to get the whole thing hot enough to produce such fine ash that it was blown out as a matter of course

Not that either result is particularly good to breathe in...

The theory is to burn off the particulates in a controlled manor so they don't come out the back (they cant get through the filter until they are combusted), trouble is the stuff that gets trapped which is not a particulate (e.g. the tiny amounts of oil).

Its this reason that dictates special oils for DPF equipped cars as they have different properties to minimise it.

I have contemplated removing mine at some point and attaching it, with flow in the reverse direction, to the towable road drill compressor at the railway and then blasting it with air whilst vibrating the case with a needle gun to see what comes out.

[Viral_Jim]

But it means diesel with DPF is not suitable for the wife, with her town only miles.

Oooo, that reminds me (just to take the thread totally off-topic), I had a thought you may not have considered on your big car hunt - Kia Sportage. Not many around but they do come in 1.6 petrol auto form. I think a 3yr old one would bust your budget, but with a 7yr warranty, would there be an issue going a couple of years older?

Just a thought

[Marks DTM Calib]

Yes, I have noticed that the re-gens only occur on my way back from work. In the heat yesterday on the way home I felt it took longer on a cycle. The way I can tell is idle is 1 bar higher on the needle compared to normal, took about 30 mins to do a cycle yesterday.

Hence I can see diesel working for anyone with a commute of at least 40 mins, or like TD the car engine is on all day in taxi work doing an idle-based re-gen. But it means diesel with DPF is not suitable for the wife, with her town only miles.

If I still have the VW at 160/70/80k I don't see it being an issue getting it removed and cleaned.

That sounds a long while for a regen, ten minutes is typical, some only five.

The later diesels have the DPF right next to the turbo (which is not great for the turbo and makes removal tricky!) so they regen quicker, mine is a bigger unit and mounted under the floor so easy to get to.

Static regens need to be avoided, as there is no load on the engine you get bore wash and the oil gets contaminated with diesel (and in the case of the two Volvos at work, they ran on the raised oil level which get into the breathers until a rod was thrown!)

[tunnie]

Yes, I have noticed that the re-gens only occur on my way back from work. In the heat yesterday on the way home I felt it took longer on a cycle. The way I can tell is idle is 1 bar higher on the needle compared to normal, took about 30 mins to do a cycle yesterday.

Hence I can see diesel working for anyone with a commute of at least 40 mins, or like TD the car engine is on all day in taxi work doing an idle-based re-gen. But it means diesel with DPF is not suitable for the wife, with her town only miles.

If I still have the VW at 160/70/80k I don't see it being an issue getting it removed and cleaned.

That sounds a long while for a regen, ten minutes is typical, some only five.

The later diesels have the DPF right next to the turbo (which is not great for the turbo and makes removal tricky!) so they regen quicker, mine is a bigger unit and mounted under the floor so easy to get to.

Static regens need to be avoided, as there is no load on the engine you get bore wash and the oil gets contaminated with diesel (and in the case of the two Volvos at work, they ran on the raised oil level which get into the breathers until a rod was thrown!)

Was longer than usual, normally it is around 10 mins as you say. I put it down to the heat  - As normally it's finished within 10 mins. Might do a plug in tomorrow, see what's what.

[Nick W]

There are a firms who will take a DPF and reverse flush the ash out (its been a common thing on lorries for some time)

We tried 4different companies who 'specialised' in that, and found them no more effective than using a pressure washer: good for about 2000miles before I had to crawl back to base at 25mph. A new cat/dpf was £3k, but it only took 10minutes to fit

[ronnyd]

Does using a car that has adblue make any difference to the DPF filter, (or is it an either/or situation? Please indulge me.