Technical DPF - best advice for maintaining same please

[nec]

I have done a search to find info but as always there is no composite site that I have found so far. :bang:

First time with a DPF - Diesel Particulate Filter - so I am looking to understand the subject better. The threads provided often talk about regeneration and other matters. How do they work and what is the best way of keeping them clear please?

Thanx in advance

 

[RichDoblo120]

They're supposed to be self cleaning, there's a warning light that comes on when you first turn on the ignition that, I think, tells you it's cleaning itself.
I've heard of problems though, some owners have had to have them changed.

 

[T14086]

Leave it alone....no need to do anything to it as its not like the fluid system on the ulysse.It self regenerates (burns of particles to maintain its efficency) & you dont know its happening although sometimes there is a slight burning odour.

 

[oilrag]

although sometimes there is a slight burning odour.

From your underpants if you`re standing near the exhaust :devil:

 

[T14086]

600oC

And how is Mr Oilrag thesedays

 

[oilrag]

600oC

And how is Mr Oilrag thesedays

Happy to pop back and see you in your element, Mr T

Best regards

( 6000C? that`s like the afterburner of a Typhoon

 

[Tango Dioblo]

When ours was new there was an occasional smell and the fuel consumption would fall... now it doesn't smell but every so often the fuel consumption dips and letting right off the throttle can't bring it back to normal. We always assumed this was the DPF cycle running and guessed that diesel was burning to do it?

Next time it happens I'm going to drive like hell to see if that shortens the cycle :slayer:

Rob

 

[nec]

A bit more information on the subject should someone else be interested. I could do with establishing if this is the same on Doblo's

This is taken from Ford

To reach the latest Stage IV emissions legislation, diesel vehicles require a system to clean the exhaust gases before they exit the exhaust system.

This is achieved by trapping or filtering the soot particulates produced during engine combustion. A diesel particulate filter is located in the exhaust system, downstream from the catalytic converter. The soot particulates coated with fuel additive, are stored in the diesel particulate filter until they reach a pre-defined level. At this point a process known as regeneration occurs.

Regeneration requires the exhaust gasses to be increased to approximately 500°C, much higher than typically obtained during general driving. The powertrain control module (PCM) uses control of the fuel and air systems to achieve this.

Regeneration is initiated at between 300-1000 km (186-621 miles) or earlier if the engine management system dictates.

The distance is dependent on the soot accumulation, which varies with the differing drive styles.

The remaining ash particles (which is a result of the regeneration of the soot particles and fuel additive) cannot be burnt and are collected in the diesel particulate filter. The diesel particulate filter is serviced every 120,000 km (74,000 miles) or earlier depending on vehicle drive cycles

The PCM will choose the optimum time to regenerate. Under normal operating conditions the regeneration process occurs when the PCM calculates that the diesel particulate filter requires regeneration and that a number of predetermined vehicle conditions are met (i.e. coolant temp, vehicle speed & load).

The PCM will then initiate the regeneration process by the following:

closing the exhaust gas recirculation (EGR)
increase the engine load
regulation of the intake temperature and pressure through the intake air shutoff throttle
additional fuel injections (post main fuel injection)
All these changes to engine behavior will increase the exhaust gas temperature. The increase in temperature will allow the soot particles and fuel additive in the diesel particulate filter to burn

 

[nec]

More information on the subject of DPF found at

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

Still nothing unfortunately on the 'vagaries' of the Fiat DPF - but still looking.

 

[T14086]

what is it that your exacty trying to find out?

 

[nec]

what is it that your exacty trying to find out?

Mr T

Anything and everything as to what they are all about, which system is in use on my Doblo 1.3 2007, how they work, longevity, what problems are likely to come in time, what do they do to fuel consumption, costs of replacement etc - I do not have a clue at present other than the stuff above..

Thanks in anticipation.

 

[nec]

A bit more info contained on this informative site.....

http://www.italiaspeed.com/new_models/2005/fiat/doblo/engines.html

 

[DOBEE]

i had to take my Doblo back to the garage after only 3 months to have the DPF regenerated ( I have a 1.9 JTD family) as the engine warning light started to come on - atleast thats what they said at the garage. However I am concerned about the fuel consumption, especially around town. I wouldnt expect it to be anywhere near as good as on the motorway but only get 18 - 25mpg (according to the trip computer). Should I get the garage to check it out ?

 

[nec]

I wouldnt expect it to be anywhere near as good as on the motorway but only get 18 - 25mpg (according to the trip computer). Should I get the garage to check it out ?

Seems a tad low but then again not too sure how heavy your right foot is etc.

I am looking to find the optimum revs for optimum mpg. On the very first check ( I record all fuel usage) and before the DPF was presumably 'filled' it recorded 65mpg but since that check it is nearer 50 mpg (very light right foot and no excessive revs) so I question what a DPF is doing to performance. That said it has only done 3500 miles and so I hope for better things to come.

 

[rogeraitch]

My 120 has now done 21000 miles I am about to go to the garaqe for the fourth time to have the DPR filter sorted. I have changed my driving style but although I have used much higher rpm in each gear and done several long trips on the motorway I am still getting the "engine failure" light followed by loss of power as the engine tries to burn out the particulates. Is it possible there is some other fault apart from my driving style? I love the car but am really fed up with this problem
regards
Roger

 

[T14086]

Is it possible there is some other fault apart from my driving style?

Yes, ask your dealer to investigate fully, theres is a dealer service news on this but be prepared to be without your car for one or two days.

 

[oilrag]

T, How are you?

A question, How does injection of fuel occur in regeneration on the DPF equipped, 1.3 Multijet?

Are the engine fuel injectors spraying fuel into the bores on the exhaust strokes? Or is there a downstream separate injector somewhere just upstream of the particulate filter?

If it`s the former, is that why engine oil can require changing more frequently (allegedly) as un-burnt fuel injected into the bores on the exhaust stroke contaminates the engine oil by getting past the rings into the sump?

(I have been trying to work out for a while, how the engine oil is affected by regeneration and it`s all I can think of)

Regards

 

[laightsdoblo]

in answer to your question, im a renault mechanic, my dad has a doblo as a taxi, oil changes are normally required after a regeneration process because the engine runs at ectremly hot tempretures during a regeneration process.

 

[oilrag]

Cheers Laightsdoblo

Is regeneration spraying fuel straight into the bores on the exhaust stroke without combustion until out of the cylinders though? (wetting the bores)

I havn`t quite grasped that part of it, or the difference between the fluid additive system of Peugeot..

It`s the actual injection of diesel fuel (timing and origin) and point of combustion of fuel/fluid that I`m not clear about.

Thanks

 

[oilrag]

I`m assuming that the DPF diesel`s `foul their own nest` regarding oil contamination then....

Otherwise there would have been a swift rebuttal from the Forums `fiat interest` presence... as no doubt it could be detrimental to sales if `joe public` really knew the full DPF ownership detriment.. Allegedly.

:devil: