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[tunnie]

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

I understand this injected post DPF.... into the exhaust gas.

[Viral_Jim]

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

I understand this injected post DPF.... into the exhaust gas.

I made that mistake when looking at the newer merc's I thought "oo, Ad Blu, I'll get one of those, no pesky dpf to worry about" - WRONG! 

[tunnie]

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

I understand this injected post DPF.... into the exhaust gas.

I made that mistake when looking at the newer merc's I thought "oo, Ad Blu, I'll get one of those, no pesky dpf to worry about" - WRONG! 

Yep, in addition!

Luckily my VW does not use AdBlue, just the DPF. As mentioned before, it appears to be working as it should, but I do long enough runs and only long runs. I don't use it for short journeys.

[Marks DTM Calib]

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

The AdBlue is used to reduce the NOx content (the thing which is causing the most concern with diesel emissions), its injected into the exhaust and reacts with the (selective) catalyst to turn it into N2 and H2O, needed for Euro 6 compliance (although smaller cars with smaller diesels can get away with a special catalyst alone).

The DPF is there to reduce the particulate content of the exhaust so the two are mutually exclusive.

[Marks DTM Calib]

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

Many companies just do a wash or air blast, the agitation appears to be key as the ash becomes compressed into the channels in the DPF so need to be persuaded to come out

[tunnie]

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

Many companies just do a wash or air blast, the agitation appears to be key as the ash becomes compressed into the channels in the DPF so need to be persuaded to come out

I've some companies do this with DPF in place, exhaust emits dirty then clean foam. But I guess this just removes the soot, not the ash?

[Marks DTM Calib]

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

Many companies just do a wash or air blast, the agitation appears to be key as the ash becomes compressed into the channels in the DPF so need to be persuaded to come out

I've some companies do this with DPF in place, exhaust emits dirty then clean foam. But I guess this just removes the soot, not the ash?

Its questionable if it can actually do anything!

It may clear them just enough to allow it to re-generate correctly.

[TD]

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....

I think your right .... was chatting to another driver earlier who used to drive a Passat...
His DPF failed at 140k...
Took it to local garage....who didn't want to know about changing it..
The went to VW in Swindon....they took a look and shipped it to VW in Bristol...
A week later he got it back......

[Marks DTM Calib]

Is he walking Ok having got the bill?

[TD]

Is he walking Ok having got the bill?

He is now, it was a while ago 

[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?

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....

I think your right .... was chatting to another driver earlier who used to drive a Passat...
His DPF failed at 140k...
Took it to local garage....who didn't want to know about changing it..
The went to VW in Swindon....they took a look and shipped it to VW in Bristol...
A week later he got it back......

When you say failed, clogged of soot? or full of Ash?

All issues appear to result from in-correct use and it not completing a re-gen cycle, there does not appear to be much to actually fail in terms of it physically working?

[Varche]

tunnie, keep talking the DPF's up. Not much else available here unless I resort to a small petrol car and a trailer for shopping, MIL, dog and wheelchair etc

The million dollar (euro?) question then is how do you know a diesel has  had correct use and completed re-gen cycles, when you are buying secondhand? Perhaps only buy something with impossibly high mileage?

[tunnie]

tunnie, keep talking the DPF's up. Not much else available here unless I resort to a small petrol car and a trailer for shopping, MIL, dog and wheelchair etc

The million dollar (euro?) question then is how do you know a diesel has  had correct use and completed re-gen cycles, when you are buying secondhand? Perhaps only buy something with impossibly high mileage?

Yes I don't think people realise or just don't want to and want to take the pi$$ of DPF's - But there is severe lack of petrols about currently, it's all diesels in mid-range budgets.

I don't know yet what can cause (if anything) a DPF to fail, other than it's not completed a re-gen cycle or it's full of ash.

I've bought VAGCOM, so if I did pick another diesel, say Passat Estate, I'd plug that in and check it as it can give exact details. I would do this if buying from an independent dealer or auction, but as I bought my VW from large retailer, which gets all it's cars ex fleet/lease, the chance of them being heavily modified like this is very low. Could still happen though, but far less likely as only 2-3 years old generally.

[Doctor Gollum]

Acceptable oil consumption for the Vw 2.0 diesel is in the order of 1 litre every 1000 kilometers.

Where do you think this oil goes?

[Marks DTM Calib]

The brother in law currently has a 540 (lease car) in Munich, its being replaced by the V6 turbo option but, the lead time has gone off the scale due to everybody running away from the diesel versions and choosing the petrol due to concerns over just what the governments are going to do with diesel power.

So give it a few years and the tables may well have changed.