The Trooper 1815

iTrader: (31)

http://garagewire.co.uk/news/governm...-of-crackdown/

Another government crackdown.

JackClark

Good, but I think it's bull****ty, too difficult to enforce.

hodgy0_2

quick question for the informed

what is the difference between the DPF and EGR valve

it seems that DPF is newer and has some "active" technology and maybe is placed in a different past of the exhaust tract

was the EGR valve a low tech solution to the particulate issue with diesels

The Trooper 1815

iTrader: (31)

I think the easiest description is that a DPF is encased in the exhaust system and acts similar to a catalytic converter. I am not familiar with the EGR but it seems to be a mechanical regulator and not "passive" item.

We may see an ADBLUE system, as used in some large commercial vehicles, for diesels of the future.

JackClark

Already in a lot of cars.

hodgy0_2

yes a colleague has Ad Blue in his Audi A6

so does AD Blue = DPF

i.e. if you have a DPF car it automatically has Ad Blue

I was not aware that was the case if trus

JackClark

Not the case, other way round may well be true.

malevolent_sti

AD Blue has been used by Mercedes for ages, my old S-Class was a 2011MY and used an AD Blue system from factory.
It's just like de-catting a petrol car, effects the emissions but frees up the breathing. A lot of my friends have got de-DPF'd German bahnstormers, the mess they kick out under load is blinding if you're behind them! From a legal point of view it's no different to fitting a de-cat pipe to petrol, which has been going on for years anyway.

Tidgy

wont happen. As said above there is no way to tell unless you open it up, MOT wont do that.

andy97

iTrader: (1)

Death by particulates poison is huge. Many times die from particulates than are killed in road traffic accidents. DPF should be legally enforced on diesel vehicles, those caught should have vehicle immediately impounded till owner pays for emissions rectify

London failed it's clean air quota for the whole year in less than 5 days! That is disgusting, the highest polluting vehicles should be forced off the road, eg old taxis, buses and large trucks. Low/ zero emission vehicles should new be provided at discount to save lives.

andy97

iTrader: (1)

Yes there is, a particulate count for said vehicle, fails if it exceeds figure. Doesn't matter whether DPF if present or not.

I have moved away from diesel back to petrol and now hybrid in an effort to help emissions

ALi-B

iTrader: (1)

EGR is exhaust gas recirculation. Self explanatory really...a portion of exhaust gas goes back to the inlet.

It reduces NOx emissions (oxides of Nitrogen) Nasty stuff not tested by MOT but limited under EU type approval regs. It works by reducing the free air available during combustion and lowers combustion temperature..heat and air are the prime ingredients for creating NOx.

Gas boilers also produce lots of it (as they burn fuel lean and hot), but they aren't limited by any regs.

AdBlu is a Urea additive that further reduces NOx emissions

Its NOx emissions that got VW in trouble in the USA

Early EGR was low tech, these days its high tech, with flow sensing, coolers, some cars, like BMW's N-series diesels have two EGR system; one high pressure EGR, and one low pressure EGR, the aim of the latter is to limit the amount of soot being pumped back into the inlet.


DPF is a soot (particulate) filter. It filters soot (carbon), thats about it. It will pass through fuel and oil vapour. So there is nothing fancy about how it works until its full....

It is cleaned by regeneration, by getting it very hot. It uses a catalytic converter to do this, as well as changing the engine fueling (turn off EGR, activate glow plugs, inject fuel later etc), which causes fuel to burn in the catalyst and raise the exhaust gas temp.

Some cars (French, or with French engines) do have a reductant additive (Eloys) which reduces the temperature at which the soot burns off.


I for one would like to see better tests for Buses and commercial vehicles. As it clear on my travels that buses that should be EU5 equipped are spewing out black smoke when they should have particulate filters. They've either melted through, or have been bypassed. The same should apply for Taxis too. I've also heard of bus mechanics bragging about fitting bypass boxes to circumvent the adblu system.

Considering that a recent report/test showed the highest levels of air pollution in London was in areas where only Buses and Taxis travelled, indicates that its not the cars doing the worst pollution in the areas where people are most likely to breath it

ALi-B

iTrader: (1)

Death from NOx pollution should be higher as it a far worse pollutant as that can go direct into the blood stream (our lungs can filter soot). Particulate is more attributed to water pollution as it settles on the ground and gets washed away by rain.

So I think the quoted death figure from particulate-related death is suspicious, or certainly has some spin put on it by a journo/politician trying to make a headline...I'd double check its sources before believing...you may find its figure is actually from overall air pollution, which is everything in the air (NOx included). In which case its very valid and plausible.

ALi-B

iTrader: (1)

They need to make the smoke test stricter and also force manufactures to allow engines to rev fully when neutral; VAG and Renault for example often wont rev above 2000rpm...intentional? :nono?

They also need to introduce NOx testing for petrol and diesel.

There's no point in having all this EU6 emission bull crap if its not enforced or tested when the car is 2yrs+ old

hodgy0_2

thanks that clears it up nicely - I was way off the mark(ish)

Tidgy

yep, so how can the mot station check if it is present? they already have to be compliant with emissions.

madscoob

iTrader: (3)

all the dpf does at low speeds is stop soot emmissions, kind of funny to be honest when they tell you to take it for a rip every now and then at higher speeds to regen it, the irony of this the only places you can maintain a higher speed for any distance, is in the countryside, go figure, all its doing is moving the problem from one place another, not curing it

The Trooper 1815

iTrader: (31)

Errrr what about a motorway?

madscoob

iTrader: (3)

nearest one from us is 38miles away countryside all the way, come to think of it how many motorways run through the middle of a town or city ?

ALi-B

iTrader: (1)

Most DPFs can regenerate at a constant 20-30mph, so long as you drive far enough for it to complete. All Fords can as well as VAGs and N-series engined BMWs

This razzing down the motorway wives tales are just that....UNLESS there is underlying fault. Which really should be fixed.

mart360

My old seat 1.9Tdi had a particulate filter in the exhaust

(Vw AHU engine)

No mention of maintaining or anything as to what it did ...

No codes ever flagged for it, and i i did occasionally was clean the EGR..

Interestingly though, they actually recommended adding a bit of petrol to the diesel in the handbook lol

Only check at MOT was visual smoke & opacity


Mart

hodgy0_2

I have filled my diesel Audi up with petrol a couple of times (by mistake)

I swear it ran better after I had drained it and refilled with diesel (on 211k and still runs OK)