DPF Regeneration Woes - Skoda Assistance really helped

[partyboy1101]

DPF light came on last Thursday afternoon on the way back from the airport........so I thraped the **** off her for the next few miles in an attempt to clear the light, little did I know that the DPF regeneration doesn't work like that (and Skoda don't bother to tell you either!!!!)

By Saturday afternoon the DPF was still on, then the glow plug light started flashing, car went into limp home and finally the engine management light came on...........knackers!!!!

Rang Skoda assist who sent out a technician (top bloke Richard) who stuck the VAG Com on and confirmed that it was just a DPF regeneration required. Easy way to do this is to find a fairly empty stretch of motorway, fourth gear and drive at about 2000rpm, feathering the throttle, which will allow a little bit of fuel into the particulate filter and will allow it to superheat and burn of the soot. Could see the % coming down on VAG com as we drove. I was at about 20% and after driving for about 10 miles the DPF light went out as we got back to 0% and full power was restored.

If it happens to you:

1. Don't rag your car trying to clean it out - that is totally the wrong idea as all the fuel will be used for combustion therefore no superheating of the dpf

2. Do a forced regenration with a steady drive as described above.

3. Don't leave it till you go into limp home mode......its frustrating as hell and you'll need to go to a dealer to get the management light put out.

[magic62]

The optimal revs are between 2000-3250, no higher.

Beyond 3250 the regeneration process will stop.

Best is to drive between 2000 and 2500 in 3rd, as the speed will not be too high and the temperature will stay high enough in the filter to burn the soot.

5th or 6th gear at the same revs will do the trick too, but it will take a bit longer.

(doing a lot of motorways in Holland, I can often notice the regeneration process).

[riph72]

DPF light came on last Thursday afternoon on the way back from the airport........so I thraped the **** off her for the next few miles in an attempt to clear the light, little did I know that the DPF regeneration doesn't work like that (and Skoda don't bother to tell you either!!!!)

I've read lots of info from Skoda about the DPF, whether it's in the dedicated leaflet or the user guide, I can't recall. Either way, they've made considerable effort to explain it's operation.

But still, despite admitting that you didn't know what you were supposed to do when the DPF light comes on, you decided to thrash it anyway??!

[partyboy1101]

But still, despite admitting that you didn't know what you were supposed to do when the DPF light comes on, you decided to thrash it anyway??!

Yes dad!!!

[riph72]

Yes dad!!!

I thought I was making a valid point!

You didn't know what you were supposed to do when the DPF light came on, took it upon yourself to guess you had to thrash it (which it turns out was your error), then tried to imply it was Skoda's fault somehow for not educating you (despite the fact that Skoda have published lots of info relating to the DPF's operation)

All this said, the advice in the rest of your post is gratefully received

[partyboy1101]

Cheers Riph, I was using my experience from a previous diesel (a Citroen ZX Tdi) which when thrashed cleaned up the emissions beautifully!!!

Plus I spoke to the service manager at the dealer a few weeks ago who also suggested that a good thrashing would see off any DPF issues!!! Anyway, no harm done and it got me out of a family party in Morecambe - result!!!!!

[magic62]

That servicemanager needs some VAG schooling about DPFs!

If he advices to thrash the car when the filter is clogged, he should be ..........

When a diesel is thrashed, it always produces lots of soot. How can a filter clean itself when loads of new soot are pumped into it?

As I already said, the regeneration process will only occur at motorspeeds between 2000-3250. At a steady speed in a lower (3rd or 4th) gear it will be best.

Did the ZX already have a filter??

[cheezemonkhai]

No a ZX would have been an XUD or XUDt and the only filter on the exhaust would have been the air filter on the air intake (ok so only just connected, but it i is )

The reason it looked like it was cleaning up was that all the soot in the exhaust pipe got blasted out at about 2.2k rpm when the turbo came on song after a bit of lag.

[*CJ*]

Good educational piece - I'm not an avid reader of user manuals and on reading about the DPF light in the manual - my take out was that the soot was burned off at over 60mph - fine when you're near a motorway but not easy to achieve on B roads.

I don't ever remember reading about the 2-2500 rpm sweet spot. Perhaps the manual in later versions has been revised with more detail.

In my case it made f-all difference since the issue was with the DPF sensor not working properly and not initiating the burn. I guess dealers and SUK are a lot more gen-ed up these days - but my dealer at the time took 3 attempts to fix it - even replacing a faulty sensor with another faulty sensor.

Hope this is the first and last experience you have with the DPF...

[partyboy1101]

Thanks CJ, me too!!!

The guy from Skoda Assistance said that he'd never had a repeat visit to a customer with a DPF light - education is a powerful tool!!!

[jbconno]

The exact same thing happened to mine on Saturday, DPF light came on, followed by a flashing glow plug light then limp home mode. RAC came out, cleared the fault lights and advised me to take it for a long steady drive keeping it at 2000-2500 rpm. Took it for a spin round the M60 keeping it within the required revs and after about 30 mins.................. it went back into limp mode and the glow plug light and the check engine light both came on.

So despite doing what Skoda say it still didnt fix the problem and its in at Grasmere Skoda in Macc being looked at.

Been loaned a Vauxhall Meriva till mine is fixed, needless to say I was on the phone to the garage this afternoon asking them to hurry up and sort it LOL .

[youngbaz]

Picking up my first car with the DPF on Sunday, so some further clarification would be appreciated ....

• Do I take it from these posts that generating the condition when the warning light glows and some remedial action is needed is a function of driving style and/or road conditions, and not a design or quality fault in the DPF per se?
  
• If that is so, is it the case that, if a majority of one's driving is cruising at, say, 2,500-3,000rpm, the situation is unlikely ever to occur?
  
• What sort of incidence rates have been reported?
  
• In a worst case scenario, ie driving style/conditions at least optimal, how soon/frequently is the condition likely to occur?
  
• Is this a 'fault' which has now been cured on the most recently manufactured units by means of a mod or part spec change?
  
• Are both PDs and CRs affected?
  

[riph72]

Picking up my first car with the DPF on Sunday, so some further clarification would be appreciated ....

• Do I take it from these posts that generating the condition when the warning light glows and some remedial action is needed is a function of driving style and/or road conditions, and not a design or quality fault in the DPF per se?
  
• If that is so, is it the case that, if a majority of one's driving is cruising at, say, 2,500-3,000rpm, the situation is unlikely ever to occur?
  
• What sort of incidence rates have been reported?
  
• In a worst case scenario, ie driving style/conditions at least optimal, how soon/frequently is the condition likely to occur?
  
• Is this a 'fault' which has now been cured on the most recently manufactured units by means of a mod or part spec change?
  
• Are both PDs and CRs affected?
  

It's just down to what type of driving you do (genuine faults aside).

My car had the DPF light on when I bought it because it had been used as a demonstrator (short spins around the locality from cold start). It went off a few miles after I left the dealer, it's never come back on since. I drive 90%+ on motorways at approx 70ish (honest!). So yes, in answer to one of your questions, if your driving style is the "right" style for DPF, you'll probably never see the light, faults aside.

I think VAG (and I'm sure there will be similar advice for others) advise caution when buying a car with DPF if all you do is low mileage trips in an urban area, because you'll have the light coming on all the time, which requires additional higher speed cruising to turn it off again. The problem is though, I suspect it will become increasingly difficult to buy a turbo-diesel without some sort of DPF as time goes on...

[riph72]

The exact same thing happened to mine on Saturday, DPF light came on, followed by a flashing glow plug light then limp home mode. RAC came out, cleared the fault lights and advised me to take it for a long steady drive keeping it at 2000-2500 rpm. Took it for a spin round the M60 keeping it within the required revs and after about 30 mins.................. it went back into limp mode and the glow plug light and the check engine light both came on.

So despite doing what Skoda say it still didnt fix the problem and its in at Grasmere Skoda in Macc being looked at.

Been loaned a Vauxhall Meriva till mine is fixed, needless to say I was on the phone to the garage this afternoon asking them to hurry up and sort it LOL .

(From memory) The advice the RAC gave you was wrong. Had you done what they said after the DPF light first came on, you'd probably have been fine. But once the flashing glow plug light has started, it's too late to remedy it with just a drive because the DPF has become too dirty to regenerate itself unassisted.

Something like that anyway. I haven't got the leaflet in front of me!

I know for a fact that the DPF warnings come in stages, and once you reach a certain warning level, it's too late to clear the DPF just by driving, it needs cleaning and possibly even replacing if you've knackered it.

This info is all in the DPF leaflet that Skoda produce!! So it's not Skoda's fault, people aren't doing what they advise

[Plantman]

Anyone got a scan of this leaflet?

Thanks!

[partyboy1101]

(Something like that anyway. I haven't got the leaflet in front of me!

I know for a fact that the DPF warnings come in stages, and once you reach a certain warning level, it's too late to clear the DPF just by driving, it needs cleaning and possibly even replacing if you've knackered it.

When mine was put on VAG-COM (after DPF light, glow plug light and in limp home mode) the filter was at 19.7%.

Filter needs replacing at about 80% so theres a fair margin there. Christ knows how you'd get anywhere near 80%?

[jbconno]

Its typical the fault only came on as I was heading to the airport for a flight to Dubai so I never got a good chance to clear the fault properly. I tried to keep it at the stated revs till I got to my parents house (as I park there when away) and when I fired it up after I got back the light at first went out but after a few miles came back on.

After trying to clear it as per the instructions (keeping it above 60kph for 10 mins) the emissions light came on followed by the flashing glow plug and limp home mode.

According to he garage they have carried out a software update/recall and are waiting to hear back from Skoda as they sent off some info for them to look at. Looks like I will be in my Meriva for another day.

[jbconno]

Just heard from the garage, seemingly its the exhaust pressure sensor thats faulty and they wont be able to get hold of one till Friday now.

[cheezemonkhai]

When mine was put on VAG-COM (after DPF light, glow plug light and in limp home mode) the filter was at 19.7%.

Filter needs replacing at about 80% so theres a fair margin there. Christ knows how you'd get anywhere near 80%?

Age, each time you clear it it doesn't go down to zero, just closer to zero.

[riph72]

The exact same thing happened to mine on Saturday, DPF light came on, followed by a flashing glow plug light then limp home mode. RAC came out, cleared the fault lights and advised me to take it for a long steady drive keeping it at 2000-2500 rpm. Took it for a spin round the M60 keeping it within the required revs and after about 30 mins.................. it went back into limp mode and the glow plug light and the check engine light both came on.

So despite doing what Skoda say it still didnt fix the problem and its in at Grasmere Skoda in Macc being looked at.

I've got the leaflet in front of me now.

Skoda's advice is, once you have two warning lights on (it looks like DPF and "check engine" [can't recall if this is the correct term] from the pics though), drive it straight to a Skoda retailer.

We can argue the toss about whether this is actually needed in all cases, but this is their advice, nonetheless.

[jbconno]

As soon as I got the check engine light on I called HSBC/RAC and got them to come out and check it over. When they couldnt fix it I took it off the road and got it recovered to the dealer.

Its probably me but its not been running right for a month or so now, hopefully it wil be back to its old self when I get it back.

[riph72]

As soon as I got the check engine light on I called HSBC/RAC and got them to come out and check it over. When they couldnt fix it I took it off the road and got it recovered to the dealer.

Its probably me but its not been running right for a month or so now, hopefully it wil be back to its old self when I get it back.

Sounds like you did it "by the book"!

[jbconno]

Got it back this morning, seemingly it was the pressure sensor that was at fault and no amount of driving steady to clear the filter would have fixed it. They also downloaded some new software to into it so hopefully wont be seeing the DPF light for a while now.

[bahnstormer vrs]

Got it back this morning, seemingly it was the pressure sensor that was at fault and no amount of driving steady to clear the filter would have fixed it. They also downloaded some new software to into it so hopefully wont be seeing the DPF light for a while now.

That sounds like the 26E6 Remap and fitting of modified Exhaust gas pressure sensor that has been in circulation since June/July 2008. It one of those mods that Skoda do on a 'if it aint' broke, don't fix it basis'.

My advice, for what its worth; If you have a VRS TDI registered before June/July 2008 get it down to your dealer for the 26E6 remap to be done ASAP (if it hasn't been done already) and save yourself a whole load of hassle later.

[jbconno]

If you get the software updated will it prevent the sensor from going faulty or are the two linked ?