Diesel Particulate Filters

[Mark]

I don't have one myself, But I was wondering, what the regeneration process is all about? And how you go about doing it?

And what happens if you don't do it?

[Daniel]

I don't have one myself, But I was wondering, what the regeneration process is all about? And how you go about doing it?

And what happens if you don't do it?

It does it automatically. The engine ECU decides when to do it based on the way the car has been used and then pumps a bit of extra fuel in which burns in the DPF and burns the particulates in the filter off.

[ioan]

It does it automatically. The engine ECU decides when to do it based on the way the car has been used and then pumps a bit of extra fuel in which burns in the DPF and burns the particulates in the filter off.

It depends on the car.
On my 3 years old Audi A4 once the particle filter blocked message is shown I need to go for a drive about 30 minutes on the highway constantly keeping the revs over 2000 rpm. This will burn the particles that are clogging the filter.
As I drive a lot within the city on automatic mode I need to do this every 2 months or so.

[GridGirl]

The specialist VW RAC man came and replaced a knackered sensor and regenerated the DPF. Now after two and a half day's I'm no longer stranded in the Lake District and will have to go to work on Wednesday. Now I've got to go to Leicester. So not fair!!!

[Daniel]

It depends on the car.
On my 3 years old Audi A4 once the particle filter blocked message is shown I need to go for a drive about 30 minutes on the highway constantly keeping the revs over 2000 rpm. This will burn the particles that are clogging the filter.
As I drive a lot within the city on automatic mode I need to do this every 2 months or so.

Yup. I actually said the same thing to Mark in an email. Personally I think DPF's are more trouble than they're worth. They reduce fuel economy, they're not suitable for vehicles which spend their whole lives in cities and they're just another thing to go wrong. Also, if things go bad the extra diesel injected into the engine can make its way into the sump and that's not good......

[ioan]

Yup. I actually said the same thing to Mark in an email. Personally I think DPF's are more trouble than they're worth. They reduce fuel economy, they're not suitable for vehicles which spend their whole lives in cities and they're just another thing to go wrong. Also, if things go bad the extra diesel injected into the engine can make its way into the sump and that's not good......

I guess that driving over 2000 RPM for 30 minutes can not be that bad, I just need to use the tiptronic shift every 2 months! ;)
My local technician told me that VW and Skoda engines are using this method of injecting a surplus of fuel, however he says he prefers the Audi way of generating the extra energy and heat by keeping the engine at a higher regime for a longer period of time.

As for what the DPFs are worth, I am certainly glad that less crap is out in the air we breath even if maybe the added fuel consumption negates the gains.

[Daniel]

I guess that driving over 2000 RPM for 30 minutes can not be that bad, I just need to use the tiptronic shift every 2 months! ;)
My local technician told me that VW and Skoda engines are using this method of injecting a surplus of fuel, however he says he prefers the Audi way of generating the extra energy and heat by keeping the engine at a higher regime for a longer period of time.

I may be wrong but I was under the impression that they were one and the same method. The extra fuel caused the car to rev a little faster.

[ioan]

I may be wrong but I was under the impression that they were one and the same method. The extra fuel caused the car to rev a little faster.

I have got no more info. he said that there is something injected (I supposed fuel as I don't see what else it could be, maybe it's something else) and this creates a higher working temperature without the need of keeping the revs high, and he said that this is done automatically unlike me having to take the highway.

If we would have had this thread yesterday I could have asked today as I had to visit Audi for a new set of windscreen wipers.

[Daniel]

I have got no more info. he said that there is something injected (I supposed fuel as I don't see what else it could be, maybe it's something else) and this creates a higher working temperature without the need of keeping the revs high, and he said that this is done automatically unlike me having to take the highway.

If we would have had this thread yesterday I could have asked today as I had to visit Audi for a new set of windscreen wipers.
I really don't see why different VAG products would employ different ways of regenerating tbh

http://en.wikipedia.org/wiki/Diesel_particulate_filter#Regeneration

[ioan]

I really don't see why different VAG products would employ different ways of regenerating tbh

http://en.wikipedia.org/wiki/Diesel_particulate_filter#Regeneration

That's what I thought too but he was very sure that it is different, so I didn't bother with it anymore since then.

One thing that is sure is that VW does it automatically (checked with a co worker) and I have to do it myself.

[airshifter]

That's what I thought too but he was very sure that it is different, so I didn't bother with it anymore since then.

One thing that is sure is that VW does it automatically (checked with a co worker) and I have to do it myself.

Manual or automatic, the desired effect in this case is simply to raise exhaust gas temps to whatever they are seeking to clean the filter yet not cause any other issues. It's easy to intentionally gas EGTs in a diesel engine by simply adjusting injector timing. A poor performance oriented tune would raise EGT in the same way. It sounds like the newer VW is simply programing this feature in, rather than forcing the driver to do it manually such as with your car.

[GridGirl]

I thought that it automatically did it itself. You only have to do it yourself when the DPF warning light comes on the dashboard when the sut levels get to a more critical level. When we were driving to the Lakes on Friday night the car wasn't happy at 1800revs most presumably because at this rev range it was trying to regenerate itself. You have about 50 or so miles to regenerate it yourself before the engine goes into limp home mode and will then not rev above 1500rpm. Unfortunately the attempts to regenerate the Octy vRS would not work because of a knackered sensor. The specialist VAG RAC man used a quarter of a tank of fuel to regenerate it from limp home mode. The DPF light warning light has only ever come on 3 times on the Octy vRS and it will be three years old in March. Ironically the previous time the warning light came on was driving to the Lake District. It definately doesn't use a quarter of a tank of fuel when you regenerate it yourself.

I also know someone who ignored the DPF warning light. They were a bit miffed in the resulting £1k repair bill. Stooopid!

[Daniel]

I thought that it automatically did it itself. You only have to do it yourself when the DPF warning light comes on the dashboard when the sut levels get to a more critical level. When we were driving to the Lakes on Friday night the car wasn't happy at 1800revs most presumably because at this rev range it was trying to regenerate itself. You have about 50 or so miles to regenerate it yourself before the engine goes into limp home mode and will then not rev above 1500rpm. Unfortunately the attempts to regenerate the Octy vRS would not work because of a knackered sensor. The specialist VAG RAC man used a quarter of a tank of fuel to regenerate it from limp home mode. The DPF light warning light has only ever come on 3 times on the Octy vRS and it will be three years old in March. Ironically the previous time the warning light came on was driving to the Lake District. It definately doesn't use a quarter of a tank of fuel when you regenerate it yourself.

I also know someone who ignored the DPF warning light. They were a bit miffed in the resulting £1k repair bill. Stooopid!
It does do it automatically. Usually people won't even notice that it's performing a regen. I'm surprised that it's used a 1/4 of a tank. Shouldn't really :mark:

[GridGirl]

I'm guessing it used a quarter of a tank of fuel as it had already gone into limp home mode and the fact that it had been sat outside at sub zero temperatures for 2 and a half days and was clap cold when put on the regeneration programme by the special VAG man.

Special VAG RAC man has been having a very busy week. I'd be interested to know how much fuel he used on the 2.7l Audi he regenerated before us.

[Biggy]

Hi i have an 08 Audi a4 and the particulate filter light has started flashing and the car has gone into limp mode. What should I do. Is the car ok to still drive about

[D-Type]

That sounds like a job for a garage.

[Mark]

If you can restart it and it will drive normally, take it for a motorway blast. If it remains in limp home after a restart then you'll need to take it to the garage.

[Daniel]

Hi i have an 08 Audi a4 and the particulate filter light has started flashing and the car has gone into limp mode. What should I do. Is the car ok to still drive about
To the garage? Yes. It needs a forced regen. If you don't then, and I don't exaggerate, this is a possibility
http://www.youtube.com/watch?v=aH9Kz9rSV4s&feature=related

[Daniel]

http://www.youtube.com/watch?feature=endscreen&v=Fw2r_lIRgpY&NR=1

More diesel runaway fun. Seriously though, it's best to take it to the garage, as soon as the oil level starts rising in the sump you run the risk of the engine starting to run on its oil and that is not something you want.

[Gregor-y]

It worked for FIATs 40 years ago, though I bet a diesel still doesn't rev that high.

[driveace]

Just read on Internet about a company at Doncaster who remove the DPF from the exhaust system on any car and replace it with a straight through new Stainless Steel pipe.They also re programme the ECU ,and promise that you will never ever have a dash light warning or ant other problems with "Get you home mode" with the DPF .They also state that as we all use low sulphur diesel in the UK ,and a DPF is unnecessary in the UK .My mechanic says that the EU made these compulsory,to save the German car companies having to spend money on newer more efficient engines.

[Mark]

I'm thankful that I seem to have bought one of the last diesels without one!

[Gregor-y]

That sounds about as honest as many locals in the Subaru community removing the catalytic converters from their cars and putting a fuse in the sending wire for the sensor to create a closed loop and keep the warning light from appearing. Mainly because they want a larger diameter pipe and the catalyst material isn't cheap.

In the US it's quite illegal. I'm not sure what tampering with emissions equipment in Jolly Olde is like, though.

[Mark]

It really depends on what the MOT requirements are, which tend to lag behind developments. I'd be surprised if DPF is part of the test.

[Rudy Tamasz]

Just read on Internet about a company at Doncaster who remove the DPF from the exhaust system on any car and replace it with a straight through new Stainless Steel pipe.They also re programme the ECU ,and promise that you will never ever have a dash light warning or ant other problems with "Get you home mode" with the DPF .

That's what we did with our car. It accelerates better now and has a better fuel economy.

[D-Type]

That's what we did with our car. It accelerates better now and has a better fuel economy.
But is it legal? The law varies in different countries as does the penalty for breaking it.

[Rudy Tamasz]

But is it legal? The law varies in different countries as does the penalty for breaking it.

I guess it's legal in my country. If it's good enough to pass the tech examination with the road police, it must be legal.

[SGWilko]

It depends on the car.
On my 3 years old Audi A4 once the particle filter blocked message is shown I need to go for a drive about 30 minutes on the highway constantly keeping the revs over 2000 rpm. This will burn the particles that are clogging the filter.
As I drive a lot within the city on automatic mode I need to do this every 2 months or so.

An Italian tune up is required......

[SGWilko]

http://www.youtube.com/watch?feature=endscreen&v=Fw2r_lIRgpY&NR=1

More diesel runaway fun. Seriously though, it's best to take it to the garage, as soon as the oil level starts rising in the sump you run the risk of the engine starting to run on its oil and that is not something you want.

Nowt to do with a DPF - likely worn seals on the turbo allowing the engine to run on its own oil.

[Daniel]

Nowt to do with a DPF - likely worn seals on the turbo allowing the engine to run on its own oil.
Which a DPF equipped car can do if its overfilled or if it does too many regens which raise the level of oil high enough. It was merely an example of what a DPF equipped car can do when things go wrong.

[Daniel]

I took one of the pipes off my turbo and there was oil in one side and not the other. Probably due to the epic overfill the garage did. I was afraid it would get to the stage where the engine started using its own oil and the AA chap suggested I get rid of the car as soon as possible as it was difficult to determine what the damage was. I still don't know how you manage to put over a litre of oil too much after an oil change! I don't know an awful lot about cars as you can probably guess lol.
Best thing to do.