Diesel Particulate Filter

peterwalkley said:
lower tax band
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lol

and considerably higher MPG than the petrol equivalent.
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You know that's down to the fuel used rather than the DPF? If anything removing it would help even more.

manic_man said:
Apart from when they actually go wrong, I'm not entirely sure why people panic about a DPF regen cycle, the engineers who design these things have actually thought about how they work and peoples driving habits!
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I question that statement - more like they're put there to get the cars through Euro V and sod the actual DPF as long as it lasts at least long enough for it not to be the dealer/manufacturer's problem anymore.

If driving habits mattered you wouldn't see tiny town cars with small complex diesel engines as people would be advised not to buy them and there just wouldn't be a market there.
 
Tute said:
lol



You know that's down to the fuel used rather than the DPF? If anything removing it would help even more.



I question that statement - more like they're put there to get the cars through Euro V and sod the actual DPF as long as it lasts at least long enough for it not to be the dealer/manufacturer's problem anymore.

If driving habits mattered you wouldn't see tiny town cars with small complex diesel engines as people would be advised not to buy them and there just wouldn't be a market there.
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There's a big difference between the engineers who design these things and the car sales people/marketing department who sell the wrong choice of car to someone. The engineers design the best they can given a specific remit and a box of off the shelf parts usually.

Undoubtedly the very premise of a DPF is going to have a limited life span, the concept isn't new, as has already been said and is akin to many scrubbing processes used throughout industry, as with any scrubbing device, it will eventually fail. However, I think you underestimate the expertise that goes into the design of things like the DPF, I was recently talking to an Audi engineer about this subject exactly and he was describing the algorithms required to calculate the best regen patterns, they were quite complex!

I personally think there are definite benefits to the mass of diesel cars out there not constantly pumping out carbon but instead occasionally blurting out ash, especially for those sat in the car behind them...

It is unfortunate though that the technology is expensive and because of the temperatures required, will always be something that is likely to need replacing before the end of the lifespan of a vehicle.

I still don't think the average car user should know they are even there unless they need to, i.e. the unit is going wrong and not performing within parameters.
 
MOOGLEYS said:
You would be better going for a run down the motorway and keep the revs at around 2.5k f
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Eventually though, they all succumb to contamination of uncombusatble deposits that come from fuel, silica, oil additive residue and metallic wear particlles. That's what seemed to happened to mine at 155,000 miles the regeneration just wouldn't clear the back pressure and this snowballed over ~6 weeks until it started to make the turbo hot and the power was very reduced when hot. As they were so expensive at the time, I had it turned into a centre box and now have 215,000 miles and it runs beautifully, pretty much like it did when new.
 
MOOGLEYS said:
The media has made people panic over DPF issues. Just make sure you do a monthly decent run and you will be fine. If the light comes on just go for a spirited drive.

They have been in use for 20 odd years without major problems.
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20 years? Nothing like that.
 
[TW]Fox;26559371 said:
20 years? Nothing like that.
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Mercedes Benz introduced them in 1985 for road vehicles. They have been used on off road vehicles and trucks since 1980.

It's only recently due to new emission standards that they have become widely used.
 
The new Skoda I have has done a regen 4 times now maybe 5 in 3000 miles, only 3 weeks old. Can tell when its doing its business as the fan kicks in really loud and the revs stay over 1k they do not drop, not had any lights on yet so it must be doing its job, however the Focus I had I never noticed it, must be a Skoda VW thing?
 
Try switching to v power or ultimate fuels. These burn cleaner giving less soot and in turn less to block up the dpf.
 
The top up fluid used to cost a fortune on my dpf. Also the filter needed replacing at around 120000 miles. I hated the thing!
 
MOOGLEYS said:
Mercedes Benz introduced them in 1985 for road vehicles. They have been used on off road vehicles and trucks since 1980.

It's only recently due to new emission standards that they have become widely used.
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They won't work to the modern emissions though; where a much higher cell density is required and hence more likely to block!
 
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pokerking said:
, must be a Skoda VW thing?
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A guy on the leon forums collected a ton of info on his PD170 with DPF (I am not sure if this applies to the CR TDI VW group use) and while it's not likely to be the most up to date, it gives an insight into what's required for the light to come on in driver style (it's fairly large)
As a MK2 Leon DP170 owner I have collected a lot of info on this subject, this is why my soon to be new car is a CR170. so here goes.

There are 2 types of regeneration, passive and active

During long motorway journeys, passive regeneration will occur. This needs no intervention from the engine control unit. Due to the raised exhaust temperatures on a long journey
(temperatures between 350 and 500°C), the procedure occurs slowly and continuously across the catalytic-coated (with platinum) DPF. The catalytic-coated DPF is situated
close to the Engine, therefore the exhaust gas temperature is high enough (500°C) to ignite the soot particles.
Due to this soot is burned-off and is converted into a smaller amount of ash.

Active ‘regeneration’ is when the ECU intervenes when the soot loading in the DPF is calculated to be 45%. The procedure lasts for about 5 – 10 minutes. Specific measures are taken by
the ECU to raise the engine exhaust temperature to above 600°C, these include switching off the exhaust gas recirculation and increasing the fuel injection period to include a small
injection after the main injection. The soot particles are oxidised at this temperature.

The ECU will trigger a regeneration process, if for some reason this is aborted, ie. customer slows down, stops etc, the process will be resumed when
regeneration conditions are once again met, above 60km/h (38mph). This will continue for 15 minutes.
If after 2 attempts of 15 minutes, a successful regeneration has not been possible, the loading will increase. At 50% soot loading, the ECU will continue to
maintain maximum exhaust temperatures of 600°C to 650°C to cause a regeneration process. The system will try to run a regeneration process for 15
minutes. If unsuccessful, the system will repeat this process for a further 15 minutes, if still unsuccessful, the DPF light on the driver display panel will then be lit.



You can monitor the soot level in the DPF with Vag-Com, here's how.

Connect laptop to the car and open Vag-Com
click on select control module
click on 1 engine
click on 8 measuring blocks
block 75 collumn 1 lambda is the soot loading in this case.
You can measure 3 blocks at the same time
block 68 collumn 2 is soot left after regen. A value of 60 means time to replace the DPF

You can also do a forced regen if you do get a blocked DPF, here's how.


Prerequisites (General):

Ignition ON
Engine ON (Idle)
Coolant Temperature above 50 °C (see MVB 002.4)
Particle Filter Load below Specification (see MVB 075.3, VAG-COM should give the specified value)
If the Particle Filter Load is above Specification the Particle Filter needs to be replaced since the car may burn down when regenerating.
Power Consumers ON (Light, Seat Heating, Front/Rear Window Heater, Climate Control)

Conditions (Driving Cycle):

Vehicle Speed between 30-60 km/h (18-37 MPH)
Engine Speed between 1500-2500 RPM (4th or 5th Gear, Automatic Transmission in Tiptronic)
Duration approx. 15-20 Minutes
Exhaust Gas Temperature before Turbo Charger above 700 °C

Drive the car based on the above conditions until the Particle Filter Load is as low as possible (close to 0*%). In case the regeneration fails there can either be problems with the Driving Cycle Conditions or with the Engine Hardware.

[Select]
[01 - Engine]

[Coding-II - 11]

Enable Regeneration by Entering 21295.

[Do It!]

[Meas. Blocks - 08]
Select both Groups at once 070 and 075.
[Go!]
MVB 070.1: Regeneration Status (xxxxxxx1 = Normal Regeneration active, xxxxxx1x = Forced Regeneration active)
MVB 070.3: Regeneration Counter/Timer
MVB 075.1: Exhaust Gas Temperature before Turbo Charger
MVB 075.2: Exhaust Gas Temperature before Particle Filter
MVB 075.3: Particle Filter Load
MVB 075.4: Exhaust Gas Temperature after Particle Filter

Now Start the Driving Cycle and keep watching the Measuring Blocks (2nd Person required).

[Done, Go Back]
[Close Controller, Go Back - 06]



As far as I know the CR170 and CR140 don't have DPF issues because they are a much cleaner burning engine so don't worry too much...................
I motorway commute so I don't see them often, about 1 every 6 months that I notice although it is likely I am triggering passive regen quite a bit.
 
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