DPF removal? Better think again!

[GiveMeABreak]

I think you're on safer ground there - a big difference between removing bad performance and removing the emissions controls!

[Goc3k]

DPF's always seem to warm the blood. Taking a step back and viewing the full picture reminds us of the "bigger" problem. I'm going to remain devils advocate here to give a fresh perspective. Thoughts:

Fine particulate matter is especially bad for our health, regulation pushes progress. So, less particulates is great news. Unfortunately these standards were initially met with the tacky bolt on that is the DPF, innovation takes time after all.

Think back a few decades. Catalytic converter (cat) craze in the 90's was ridiculous, they were very expensive and not long lived parts. Some even failed in an outright dangerous fashion.

The first and second generation versions of the cat were a similar breed of absolute rubbish, even I remember cats melting owing to poor fueling characteristics in some cars (some early motronic systems having cats fitted for example), and they were up to a grand on higher spec vehicles for just the unit. But today? Easily get a cheap cat for a small family car for £100-200 . DPF's have gone exactly the same route, filters for the later generation small engines are now only around £300. Which is fine.

But, we're at a point where for a few years now all those naff first gen vehicles are on the used car market, ruining peoples wallets. The average person knows absolutely nothing about cars, I doubt most people even know what a DPF is and how it's going to be a big problem on a 5-6 year old 80-100k used diesel they have purchased.

So we now have a mass of used cars with expected lifetimes a bit shorter than they were. Example - over a 10~ year period, a small (such as a modern Citroen C1) car produces about as much pollution in emissions as it did to manufacture, so that's ten years of driving a C1 produces a C1's worth of pollution (merely example numbers!). Heavy high spec cars are hugely costly for the earth to produce, 4-8 times more than the little C1 depending on what model. - SO, every extra mile that a car covers, be it big or small, instead of going for scrap and a NEW car being manufactured is green points for our earth. A nasty old gas guzzling v8 that has racked up 300k miles over 25 years, has a less extreme global pollution impact than replacing that car every 3-10 years, even with ultra modern green cars. The monstrous cost to the earth of producing a power pack for a modern electric vehicle, is much the same problem. Running figures look great, production figures are comparatively shocking. So, the longer a car lasts (even if old, inefficient and tampered with), the lower its overall pollution value becomes.

Another angle, say I criticize my neighbor Fred for removing his DPF at 120k miles. How irresponsible of him. I am annoyed fred has shirked his environmental responsibilities, by messing with his broken emissions system and driving such a vehicle.

My other neighbor Bob, then gets in his car to pop down the shop to get the paper. He's driving a 25 year old 1.9td Citroen BX he's had for years. it's a wretched black belcher by modern automotive emissions standards, producing a lot more particulate pollution and a disgusting amount more nitric oxide and nitrogen dioxide (regardless of whether Fred's car even has an exhaust system attached at all). I simply wave and bid him good morning.

Later, I have a conversion with a visiting friend about the fact I am not impressed with my neighbors high emissions vehicle. My friend replies "Yeah, that guy really needs to replace that ancient Citroen BX"

So to conclude: environmental impact is much bigger and vastly more complicated than the face values we perceive and are presented by the government / manufacturers.

Sadly my neighbors are not called Bob and Fred. Sorry

Also, Mazda might have an exceeeeeeedingly poor reputation when it comes to DPF's, but look into their current SKYACTIV-D (No DPF fitted!) engines that beat emissions legislation not even implemented yet, with a huge NOx reduction as well. Obviously full of other non-simple probably going to break and cost a fortune parts, but it's some good progress

[Goc3k]

It would be good if somebody could do a write up with pics on a DPF remove, clean & replace.

I've helped a friend sort the DPF out on his mk5 golf previously (the dodgy 170bhp one). We jet washed it, then soaked it in high grade carbolic acid - the stuff binds to the fats in your skin and effectively causes you to melt if you touch it. Really the acid needed to be boiling, and then it needed to be baked in an industrial oven to get the last hard carbonized stuff out. No idea how long it lasted, but the power / mpg was back and the eml light stayed off after it was reset. He flogged it 3k miles later, no idea how long it lasted with the next owner.

Dangerous job best left to the professionals if you have the time and don't need the car too sharpish I'd say. (plus the carbolic acid degrades the catalytic converter elements in the DPF to a degree they no longer function, no idea what the proper stuff the pros use is)

[Paul-R]

...plus the carbolic acid degrades the catalytic converter elements in the DPF to a degree they no longer function...

Is the DPF and catalytic converter on VWs all in one piece? I thought they could be separated on Pug/Citroen cars?

[Stickyfinger]

Looking at cars over the last 4 days (lots of miles), I have noticed the smokers (a few really BAD ones) were all VW/Audi.....why would that be ?

[GiveMeABreak]

There are a few different systems for sure, some don't use additive but increase the engine temp, some just use passive regeneration, but by all accounts the PSA one is arguably one of the better systems, but certainly PSA say it is the most efficient in the world as they invented the additive DPF:

http://www.psa-peugeot-citroen.com/en/f ... ate-filter

[elma]

Looking at cars over the last 4 days (lots of miles), I have noticed the smokers (a few really BAD ones) were all VW/Audi.....why would that be ?

I think it depends when you're out, the marque I keep noticing puffing out the smoke is Vauxhall.

[GiveMeABreak]

Looking at cars over the last 4 days (lots of miles), I have noticed the smokers (a few really BAD ones) were all VW/Audi.....why would that be ?

I think it depends when you're out, the marque I keep noticing puffing out the smoke is Vauxhall.

I think you'll find they've had their DPFs removed or gutted, if the DPFs are there and working properly you should only get some greyish smoke not the full on chimney sweep stuff of the 1990s!

[Goc3k]

...plus the carbolic acid degrades the catalytic converter elements in the DPF to a degree they no longer function...

Is the DPF and catalytic converter on VWs all in one piece? I thought they could be separated on Pug/Citroen cars?

Nah it has a centre cat as well, we didn't crack it open to confirm when cleaning it as to avoid any dodgy looking welding, but that is what I read while searching the internet for a solution. I think most modern cars have multiple catalytic converters nowadays, but happens the precat is in the DPF on that particular VW. *i think* Not sure what PSA systems contain, but im under the impression having a cat element in DPF's is common, at least in the regen-style ones.

The urea additive based DPF's function better over a wider range of driving styles, and it really helps the NOx output as well which is very good. The late injection "regeneration" style DPF's (first gen VW systems mostly) are the worst, both for reliability and actual ability to capture and burn off soot / pollutants.

[wheeler]

It's easier to take it off, shove a load of oven pride in it, let it sit for a while then rinse it out and jet wash it out. Job done!

Of course i assume when your doing this you are collecting all the crap & Eolys chemicals that come out of the DPF when your jet washing so it doesent go down drains/water courses/soil then taking it to a relevant disposal site that can deal with Eolys chemical disposal ??

[Xantianut]

Ay up!

Read this with interest.

My C5 HDi is the early, 110hp 2.0 8 valve so has no DPF fitted and never has had. And yet this car, which should be relatively "dirty" by modern standards isn't. Even early, non-DPF Pug HDi engines seem amazingly clean, much more so VW/Audi or Mercedes. You see the odd Ford chucking it out but not often, as for BMW and Jaguar diesels, don't they have Pug engines anyway?

Anyone know just why the Pug HDi is so clag free? Or is it just down to good design?

Never thought I'd say that about a Citroen!!!!

[Hell Razor5543]

When Citroen/Peugeot launched the HDi engine it was powerful, economical, reliable and clean. Over 20 years later it still is. I think that the PSA group have come up with a good design!

[myglaren]

When Citroen/Peugeot launched the HDi engine it was powerful, economical, reliable and clean. Over 20 years later it still is. I think that the PSA group have come up with a good design!

Except it is a Fiat design that they couldn't afford to develop and PSA took it over.

I note that as above, VW group engines seem to kick out a lot of black smoke, as do many BMWs.

[BenC5HDi]

PSA engines also do, it's just that they're less likely to be driven by knob - heads with lead feet, so you don't notice it. Even pre-remap the Berlingo would lay down a smokescreen when hammered.

Sent from my SM-N9005 using Tapatalk

[myglaren]

The best I have been able to manage was a bit of grey haze when foot to the floor, uphill out of a roundabout, display showing 9mpg.
The Subaru in the outer lane obliterated the vision with smoke when he caught up and passed me