DPF Info - All CR-TDI Owners Should Read This

[skeat12]

Keep an eye on tick over revs, it will sit a around 1k whereas normally it's slightly less. Also it won't rev over 2.5k, I've noticed the cooling fan stays on when the engine is switched off, and also a burning smell.

 

[nightflight]

Somewhat topical as I had to do a regen run this morning..

Your dealer's tight I only get billed for 30mins labour, looks like you got charged for an hour, though tbh i suppose it's upto the dealer to set their own prices. My first regen was done under warranty too, perhaps they give you one for free?

You can tell that a regen is under way as the engine will idle at 1000rpm as opposed to 750-800 and it'll feel rough as hell and the car will shake a bit at idle.

Mine revs over 2.5k rpm if the DPF light is on?

There appear to be a few differences in my experience and the article i originally posted, for example, this morning, i managed to clear my DPF light with normal town driving, by pulling away fairly quickly in 1st upto 3.5k rpm, into second and holding second at 2-2.3k rpm for general driving (about 23mph sorry to all those i held up a bit earlier, but you're not worth £1500! ) whereas the article says it has to be 60km/h+

 

[garethrobson]

My dpf light came on last night. Tried doing what was said about driving at 40mph in 4th or 5th gear but the light still seems to be on after about half an hour. At what point do I contact the dealer? Do I wait for the other intrument lights to come on aswell? Also, if those lights do come on, am I supposed to pull over on the hard shoulder and call seat recovery, or can I carry on driving home, then call the garage. Last thing I want is for my dealer to turn around and say u shudve stopped and called seat breakdown, then charge me for the regen

Cheers!

 

[nightflight]

Get it out again, ignore what it says in the manual and get it held at 2,100rpm (any gear from 2nd upwards) should only take 15minutes or so (depending on how bad it's got) remember, it needs to be a constant engine speed, so either a motorway or a long A road where you can plant it at about 35mph (2000 rpm in 3rd for me) (be really annoying to other road users for a bit) but most importantly not need to slow down.

Do that and it'll clear, if it doesn't, and the instrument light comes on, call out AA assistance as a) it'll go into limp mode and it'll be such a boring drive home.
b) whilst in limp mode the car can't regenerate the DPF, so in it's blocked state, it'll carry on getting blocked whilst you drive it home, so when it gets to the dealers monday, it'll be even more blocked, no point risking pushing it over the regen threshold intot the "need a new dpf" territory.

If it does go in, you're loking at 30 mins or 60 mins labour costs from the dealership, though I got my first one done for free.

 

[UncleFester]

I'm probably being thick here but i'll give it a go ..... can you not weld on a capped pipe to the bottom of the DPF so you can empty the contents out yourself? Or even better, a pipe that goes into the exhaust POST sensors so that it can blow clear at the push of a switch?

Has anyone taken one of these things to bits to see what's inside?

http://www.sinspeed.co.uk/blog/08/diesel-particulate-filters-dpf-problems-dpf-removal-procedures/

So it's a CAT inside effectively and has to be HOT for it to work ......

 

[andycupra]

i will soon be working with catylists and so i have some understanding of this process.

What i dont really understand is tuners that are offering DPF delete remaps, what does this adctually mean? do they simply turn off the warning? remove the filter capturing the soot?

 

[andycupra]

i've just been billed £95 for a regeneration by the dealer on my 1.6 tdi ibiza. Its less than 12 months old with only 14 000 on the clock. Is this right? I thought the warranty only didn't cover replacing the dpf.
Also i've had it regenerated at a different garage before, and it was done under warranty.
Finally nightflight, it says in your article that loss of power and additional engine lights will appear at roughly 75%. However my dpf was at 89% saturation an was still running fine.
Can anyone tell me how you can tell if the ecu is trying to carry out a regeneration?

sounds like it will seem to be running a little rough.

But it also seems to read that you have been bille £95 to complete a regen when this would be done with a 10 minute drive on the motorway..
mind you, 89% saturation.. thats high.
So do you make alot of very short trips and never give it a run out?

 

[nightflight]

DPF delete remaps as i understand it, involve removing the DPF, replacing it with a piece of normal piping, and turn off/spoof the post-dpf flow rate sensor. (along with a performance boost map usually)

 

[matt_t]

sounds like it will seem to be running a little rough.

But it also seems to read that you have been bille £95 to complete a regen when this would be done with a 10 minute drive on the motorway..
mind you, 89% saturation.. thats high.
So do you make alot of very short trips and never give it a run out?

It seemed to be running fine. i took it for an hour an 10 min drive down the motorway but the light never went out, thats why i took it to the dealer.
I do an 80 mile round trip down the motorway in it bt twice a week, the rest of the time its only fairly short journeys.
Last time this happened tho, the engine went into limp mode, and after calling out the rac to take it to a dealer, they found it was a sensor problem.
Im just wishing i bought a petrol now. lol

 

[nightflight]

What RPM were you driving it at on the motorway?

I took mine out for a motorway run once with the aim of making sure it was clear (the light wasnt on but i thought i'd play it safe and make sure it was clear anyway, last thing i wanted was the light comin in when stuck in a traffic jam!) but was only cruising at about 1500rpm and the light came on after about 10 minutes!
Sods law or what.
Anyway, my point is, it needs a constant 2,200 rpm to clear it.
(I've also tried giving it some serious stick to clear it when the light came on once, going for a full rev range assault on the a57 out towards snakes pass... ended up going into limp mode and an hour long wait for the AA man to come tow me back home. doh!)

 

[/dev/null]

I have a Leon but this is the only thread I can find which is helpful. I have the PD170 and after scanning with vag-com it seems mine is going to stage 1 regen at about 20% load!!? Is there any reason it might do this?

 

[FinGerS o FuDgE]

Just trying to figure out what the ideal speed/revs are to clear the DPF?

* On the 1st post it states "...the process will be resumed when regeneration conditions are once again met, above 60km/h (38mph)..."
* Nightflight is saying 2200rpm in 3rd (How about 4th gear? This what I usually do but not sure if this is working?)
* On this Ross-Tech emergency regen page it says between 18-37mph : http://wiki.ross-tech.com/wiki/index.php/Diesel_Particle_Filter_Emergency_Regeneration
* In my manual it says 2000rpm in 4th or 5th gear (Golf GT 170TDI).

I'm all confused...

 

[nightflight]

From my experience I think it's the rev's that are important rather than the speed or gear, i've managed to do a regen in 2nd keeping the revs at 2-2.5k round town.

 

[FinGerS o FuDgE]

Thanks for the reply
Once I figure out how to read the DPF levels through Vag com I can try using different gears to see if any make a difference??

 

[nightflight]

If you figure it out please do report back, it'd be good to get some solid figures to go on

 

[FinGerS o FuDgE]

I forgot to update what happened:

Right, cleared my DPF completely last night.


Started everything up and the DPF was @ 34.4%. Took a slow drive along to warm the car up and within 5 minutes the car had put itself into a forced regen - xxxxxx1x

Carried on driving and hit an A road where I tested driving @ 2200rpm in 3rd & 4th gears. The DPF% dropped rapidly from the 34% to around 8-10% within about 5-6 minutes of steady revs. Noticed the exhaust temperature was at a bubbly 660 degrees :O

When it hit the 8-10% mark (could have been higher as I wasn't looking) the forced regen turned itself off. I carried on driving @ the same revs and the % still dropped, albeit at a slower rate (about 0.1% every few seconds)

By the time I had got to work (12 mile) the DPF % had gone down to 3.4%

On the way home I done exactly the same revs but in 4th & 5th gear to see how low it would go, and it carried on dropping. About a mile from home the DPF % showed 0.0%

Seems to drive alot better now too. Smoother & more responsive - Especially in 1st & 2nd gears!


Lee

 

[Nath.]

What RPM were you driving it at on the motorway?

I took mine out for a motorway run once with the aim of making sure it was clear (the light wasnt on but i thought i'd play it safe and make sure it was clear anyway, last thing i wanted was the light comin in when stuck in a traffic jam!) but was only cruising at about 1500rpm and the light came on after about 10 minutes!
Sods law or what.
Anyway, my point is, it needs a constant 2,200 rpm to clear it.
(I've also tried giving it some serious stick to clear it when the light came on once, going for a full rev range assault on the a57 out towards snakes pass... ended up going into limp mode and an hour long wait for the AA man to come tow me back home. doh!)

The DPF cycle is a continuous cycle, the soot loading will gradually creep up regardless of how you drive and when the soot loading gets to 45% a regen will kick in. when the soot loading is low enough the regen will stop and the cycle will begin again of soot loading gradually creeping up.

In my experience of monitoring with Vag-Com on long journeys, Driving so as to clear the DPF when the ECU isn't in regen will do nothing to reduce your soot loading. you need to actually be in a regen in order to clear your DPF. I drove mine for 3 hrs on the motorway one time, I started off with 14% and ended up with 28%. This was doing 80 on the cruise just over 2kRPM

Another note is that when you have a DPF light on it means that a normal regen was interrupted 3 or 4 times and the light tells you to drive in a way that assists the regen process. When the light goes off the soot loading will not be 0% but just enough to make do. You should carry on with the regen driving after the light goes off (on the same journey) to get the soot level right down to 0%

This may be of interest to you if you haven't already read it.



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.

 

[Biker]

In my experience of monitoring with Vag-Com on long journeys, Driving so as to clear the DPF when the ECU isn't in regen will do nothing to reduce your soot loading. you need to actually be in a regen in order to clear your DPF. I drove mine for 3 hrs on the motorway one time, I started off with 14% and ended up with 28%. This was doing 80 on the cruise just over 2kRPM

So you say a motorway run will not help clear the DPF.

But you go on to say....

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.

Bit of a contradiction there!

 

[Nath.]

So you say a motorway run will not help clear the DPF.

But you go on to say....




Bit of a contradiction there!

Exactly, But you missed out that I said "In my experience of monitoring with Vag-Com". The last part of my post was a copy/paste from a VW forum for those that were interested. Notice that I then went on to say "This may be of interest to you if you haven't already read it" and then posted the interesting VW forum info.


I beleive that passive regeneration may occur on long motorway runs but it won't always be successful, I think that this is where the VAG DPF fails. The Vauxhall one on the 2.0 160 that I also have seems to passive regen very well.

 

[Gus 1]

I've noticed the cooling fan stays on when the engine is switched off, and also a burning smell.

Do you know why the cooling fan stays on? It's annoying me and don't want it to drain the battery