MKV DPF dissection

[gldgti]

that self study is a great read.

Greg - under "fuel quality" (right at the end) I would read that as good new for you. i.e - if you have a dpf delete, and no regen cycle happenning, then bio should be sweet.

Its great that it actually explains why rather than not. I always thought it was strange the way vw stopped saying bio was ok for their diesels right around the time the DPF's came in - before that it was just about encouraged!

anyway - as the self study mentions - the main DPF structure is made of silcon carbide coated with alumina (aluminium oxide) which is good for the platinum to bond to. the silicon carbide is a ceramic material very commonly used in these kind of applications.

You mentioned that there was a lack of black soot but a lot of ash - i would put forward a theory that the incorrect engine oil was being used - or - the oil was overfilled. This would lead to large amounts of oil vapour/ash being burned in the exhaust and subsequently clogging the DPF.

I have read one horror story from the states witha guy who bought a brand new jetta with a dpf. after just 10,000km the engine stopping at inconvenient times, because the DPF had become completely blocked. The reason - the dealer had used the wrong oil spec (he had a very early dpf car), AND had overfilled the oil at the first service. when i say the engine was failing - shutting down/refusing to restart due to fault codes.

there is an ongoing legal battle....

[jazd]

Self study is indeed a good read. Where can I get more?

I have NEVER had the active regeneration light come on in my car since I have owned it (6 months), I guess I do enough long distance driving (40km to work and back every week day) and give it enough stick!

[jazd]

In the event of failure from the temperature sender
before turbocharger, the turbocharger can no longer
be protected against excessively high temperatures.
Regeneration of the diesel particulate filter is stopped.
By means of the preglow control lamp, the driver is
informed that the vehicle should be driven to a
workshop. To reduce the carbon soot emissions,
exhaust gas recirculation is switched off.

Poor mans DPF removal? lol

[Greg Roles]

Self study is indeed a good read. Where can I get more?

I have NEVER had the active regeneration light come on in my car since I have owned it (6 months), I guess I do enough long distance driving (40km to work and back every week day) and give it enough stick!

Car does a no light active regen at 40-45% clogged, it doesn't let you know. At 60% (approx) you get the light, and it then tries like mad to force a regen, and wants you to drive at speed to get it hot. If that fails it goes on to put the car into limp mode at 75-80% clogged at which point you have to take it to VW to have it regenned with the bonnet open so it doesn't catch fire! The coli light comes on after the failed 60% regens, I've managed that already in my messing around.

[Greg Roles]

Poor mans DPF removal? lol

The above hapens eventually mate, the car will refuse to run after 80%. I've not been willing to confirm that though!

[jazd]

Car does a no light active regen at 40-45% clogged, it doesn't let you know.

Ah OK.. would be nice if it gave some indication, does it mention that in the self study or did you pick that up elsewhere?

[gldgti]

Poor mans DPF removal? lol

thats a very good point... remove dpf, disconnect preturbo egt probe (even if you have your own one installed for piece of mind) and drive around without a care? might work....

[Greg Roles]

I'm not going to be the one to try it, I experiment on my poor little TDI enough....

Anyway, I am now onto DPF plan #34....

[ryder01]

Stupid DPF. Good riddance. Still gives me nightmares! But apparently not enough to have scared me off completely from looking at a 2nd hand touareg for the family wagon. Unsure if I want to go down that path again though!

[Buller_Scott]

holy crap that thing is huge!!!! no wonder you guys are aching to get it off your cars... (i'd hate to think that there is something tucked in behind the engine of the new 1.6tdi polo!).

before dissection, was the unit very heavy, greg?

RE: the "poor man's dpf removal" it'd be nice to think that the seasoned tinkerer could pull this off, but if that were the case then surely companies like Viezu would have got their dpf delete tunes right by now? im not necessarily up to date with which tuning company is doing what, but it still seems like custom code is the way to go for a dpf tune.

thanks for the link, Ben - that's some insane reading.