Thread: Diesel Particulate Filter for Disc 4 HSE SDV6

I'm not going to wade in on the cancer stuff and can't really comment on the tech aspects of the fuel standards and how and when a DPF works....but as an owner of a 2009 D4 SE with a DPF fitted, I can certainly comment on my experience.

My car runs clean, and has never even the slightest puff of fume behind it. The exhaust has a very different smell to diesels I'm used to, quite innocuous.

I've had mine 2.5 years and I've had two regens (as in warning light comes on) and yet I drove in heavy traffic every single working day. The only reason I got a regen was the fact that I travelled through an area with miles of roadworks and there had been a prange. Everytime I felt I should turn off the engine, the traffic would inch a few feet forward (plus it was very hot outside). I was standing still or moving at less than 5kph for well over an hour. I doubt most owners would ever have their car regenarate, if driven in normal to heavy traffic.

When the car did regen....I assume it did it when the car was rolling at a decend rate of knots, as this is the owner manuals recommended way of cleaning the filter and getting rid of the warning light. At a guess, I'd say the car doesn't regen when the light comes on, only after you meet the regen parameter...but as I said, I'm guessing there. Maybe it's only at a certain high level of blockage that the light comes on and the car is constantly doing minor regens.....dunno.

As far as the actual regen activity is concerned, to get the light to go out.......you don't notice a thing.....no smoke, no noise, no obvious loss of performance. If it wasn't for the light on the dash, you wouldn't know anything had occured. On both occasions the light went out within minutes of normal driving.....not 20 or 30.

What's other D4 owner's experiences, are they the same as mine?

Cheers,

Kev.

from what I've read of the way the landy does it...

IT fires up often and for shorter periods when the vehicles speed is high and engine load is light.

IT turns on post glow on the plugs, does a late injection and spits some fire down the pipe to get the DPF "on fire" then runs a couple of pots (in a rolling sequence) low on power to spit more air down the exhaust to let the burn in the DPF breathe.

It has 2 levels of higher burn off, 1 requires you to hit the button that tells the computer to initiate the heavier burn. It can be done while driving BUT it requires you to be in a certain driving pattern.

The next level is a stationary burn off where you're required to pull over (I think it will still work if you have selected a certain gear combo, 1/low I expect) and let the engine do its thing till the DPF pressure differential says its clear.

The last stage is a dealer initiated one and sticks you in limping mode.

Just this week past, diesel particulate matter was officially declared a carcinogen. Harmful exposure levels are more of an occupational than user concern, but that said, its hardly fair that we don't at least have the option in Oz when its available elsewhere, right?

Originally Posted by Blknight.aus

does a late injection and spits some fire down the pipe to get the DPF "on fire"

... over-rides EGR valve operation to ensure they stay closed then does a late injection to leave unburnt fuel in the exhaust gas to cause the catalytic converter to reach its maximum safe temperature to generate sufficient heat to burn the particulates out of the DPF.

Originally Posted by Stuart02

diesel particulate matter was officially declared a carcinogen

So what's the situation if they are collected in a DPF over time then all burnt in a concentrated short period? Are they any less carcinogenic? Are they effectively more?

yep, Im waiting for them to introduce a second "EGR" in the intake which is intended to bleed boost air from prior to the intercooler into the DPF to allow a higher power out during the Regen.

My 2012 defender does not have one and I am glad it doesn't. The book states it will clean every 800 odd K's and you will need to be doing about 80 clicks for it to work. And if your in the bush the thing will get hot and set the grass on fire and some in other vehicles already have. In fact there is someone who is manufacturing dummy ones that look exactly the same with ports for sensors ect. Better without them less expences later.
Probably should pedal a bike if we are worried about that.
Lindsay.

Originally Posted by Graeme

So what's the situation if they are collected in a DPF over time then all burnt in a concentrated short period? Are they any less carcinogenic? Are they effectively more?

What the DPF does is catch all the unburnt particles of fuel when enough of them gather the DPF's temperate us raised and all the coolected stuff burns off.

Its not as clean as the normal exhaust emissions of a DPF fitted vehicle when its not burning But its still cleaner than the emissions if you didnt have one fitted.

Here's a ball park analogy.

Take normal every day wood, you burn it and unless its really hot it smokes.

If you catch that smoke and condense it down you get soot. if you condense the soot enough you'd get coal the coal once burning burns cleanly. Its not as clean as if you'd processed the tree into coal in the first place and then burnt that But its still cleaner than just burning the wood.

roughly....