d.p.f.

[freewheeler]

hi all,got my mind on a 110/or 140 se but i am a bit worried about the dpf.as i dont want a petrol model can anyone tell me just how much trouble these filters are?i do 20 miles per day round trip to work and a bit running around at the week ends.some of my work trip is through town which on the home part means sitting in traffic jam[dont we all].usualy do around 40/45mph untill i hit town,then the same when i leave town on way home.week end runs are on dual carrage etc.any help pease.

thanks guys.

mike.

[Agerbundsen]

hi all,got my mind on a 110/or 140 se but i am a bit worried about the dpf.as i dont want a petrol model can anyone tell me just how much trouble these filters are?i do 20 miles per day round trip to work and a bit running around at the week ends.some of my work trip is through town which on the home part means sitting in traffic jam[dont we all].usualy do around 40/45mph untill i hit town,then the same when i leave town on way home.week end runs are on dual carrage etc.any help pease.

thanks guys.

mike.

fergettaboutit - No problems or even any well recognized regenerations with mine after 10,000 miles. The 170 hp should be more susceptible (sp?) than the lower hp versions in short trips. Other than the mad dash to Spain and back, most of my driving is less suitable to diesel than what you describe. Often just a 5 mile round trip to drop SWMBO off to the bus or shopping in the same location.

[The Plumber]

Hi,

as Agerbundsen states you should have no problems.

Mine is mainly used for rural / cross country with a little bit of town work and so far in almost 6000 miles had a couple of regenerations (engine RPM rises at idle and the fan comes on) but no warning lights. To be honest I tend to forget it's there and just drive as I did with my previous Golf TDI PD (no DPF).

Also note my Monster is fitted with the first generation 140 CR, new second generation 140 (and 110) now fitted to all production Yetis.

Regards,

TP

[Thompson2]

This is a very interesting topic and worth tracking because there seems to be loads of bad press about these DPFs which I hadn't cottoned onto before I bought.

I only do urban short trips during the week and so am trying to give it a 15 min blast at constant 40/50mph each week. At the moment I am buzzing all over (average approx 100miles per week) and as summer approaches I'll be out and about with the caravan but come the winter, well, we'll see!

[Llanigraham]

There seems to as much "guff" about these "diesel particulate filters" now as there was about catallytic converters when they were first introduced. There really is nothing to worry about with them!

They have been fitted to both my Freelanders and I have never noticed any problems with them, in the 150k miles or so that I have had them. To work most effectively they need to be HOT, so people who do long consistent journeys will probably never notice them, whereas the "stop-start" urban journey person probably will see/hear the occasional increase in revs and smokey smell. No problem, that will confrim it is working.

[haggettd]

I agree that DPFs should give no problems when the vehicle is used according to the manufacturers recommendations, but that does not

mean it's good technology!

A DPF has absolutely no benefit to the vehicle whatsoever and only adds complexity and cost.

Like most things that have to be introduced by car companies it is only to satisfy the legislators, and the legislators pander to the

eco lobbyists.

The DPF will accumulate soot until it becomes partially blocked. The blockage is sensed by a differential pressure sensor and when it

reaches a certain back pressure it will trigger a regen.

The regen is achieved by changing engine parameters to make the engine work harder. There is usually an extra squirt of diesel that is injected purely

to heat the exhaust to 600 deg C. Additionally and certainly in the case of my Merc the heated rear screen was activated - again to make the engine work harder and

increase the exhaust temp.

All these things conspired to reduce my mpg to 25mpg from 45mpg whilst it was regenerating (10-15minutes) and it ran like a pig whilst doing so.

When the soot is burnt off there remains an ash residue which cannot be removed by regen. Over time, this will build and clog the filter which will then need to

be replaced at a cost of £1000 plus.

This needs to be factored in when calculating your lifetime running costs. The filter should last 100,000 miles but they often don't.

I read a technical paper from Mercedes which explained the complexity of the system and that to equip a non DPF car with all the paraphernalia required to add it would cost

7000 euro in parts alone (at consumer prices). DPF/Pressure sensors/ Oxygen sensors/temperature sensors and electronic control.

I have always been a diesel nut, but the abomination that is the DPF made me go back to petrol (1.2TSi). Yes, the petrols have catalytic converters but at least these go about

their business without having any noticeable/variable effect on the operation or driveability of the car.

Any supposed eco measure fitted to a car that demands that you either drive harder than you really want or make special open road journeys just to clean the DPF is

surely misguided and results only in using more fuel than you need to.

Sadly there is no going back as is usual with these thing so you'll just have to swallow the extra £1000 pounds on the purchase price and live with it.

A carbuncle on the face of a well loved friend as Prince charles said (though he was referring to architecture)!

So no, I am not a fan. I doubt the supposed certainty of the 'science' that originally forced the legislators hand. Too many maybes, possibilities and ifs for my liking.

I sincerely hope that things improve. DPS are relatively new and many car companies try and get their DPFs to regen in different ways, none have cracked it in my opinion.

To get an idea of what I mean take a look at mazda forums - horrendous DPF problems. And other VAG sites.

The fact that there are companies that have devised DPF bypass solutions for cars so equipped is testament to some of the issues that they can cause.

Nighty night.

[Agerbundsen]

Hagattd,

Your descriptions of the function and the potential problem are correct, but I cannot quite agree with your overall conclusions.

There are millions of diesel vehicles with functional DPF's and no problems. On the Continent, most countries have close to 50% of the vehicles fuelled by diesel - grantedely, the older ones not with DPF, but the majority of the newer ones do. The technology is something like 20 years old and has progressed from early systems with catalyst addition to the fuel to the most common system today, which regenerates by the engine controls increasing the exhaust temperature. You are also right that the ultimate problem is ash accumulation. VAG have gone to great lenghts to reduce this problem - tight specifications on fuel and lubeoil purity as well as reduced il consumption by tighter engine design.

One of the aspects of these discussions is that the few that have problems get very vocal and talk about it, but the many that don't remaind silent - there is no interest in success stories.

The drive to more efficient engines and less polluting engines have driven the technology to a point, where engine management, additions of turbocharging and electronic controls and DPF have produced engines with more power and cleaner eshaust. A truly modern Diesel engined vehicle like the Yeti is cleaner and has much better driveability than vehicles from just a few years ago.

The need for DPF is clearly evident, particularly in big cities like London. The DPF, like so many other eco improvements have made our lives better and the inconvenienced introduced are at worst inconvenient temporarily and cost some money.

In my adultlife, I have been through the Clean air Act and waterway clean ups, which have made very noticeable improvements in the quality of life.

The infamous UK smog from pre-1960's, where hones were fuelled with coal and coke in horribly inefficient fireplaces is history.

In 1970, you could not stand on the street in Chicago without your eyes watering from the car exhausts. Today you can.

Back in 1960, the Cayahoga River in Cleveland, OH, caught on fire from waste emitted from the steel mills. Today you can fish there.

The engine management systems driven initially by legislative requirements for cleaner air have resulted in much better engines and much better cars than we used to have. This includes the DPF.

Learn to accept it and enjoy the benefits.

Edited 31 March, 2010 by Agerbundsen

[jst_at_home]

I can see the points being made but have to agree with Agerbundsen.

Fundamentally, the partilcles emitted by diesel engines are measured in microns and are so small that they can easily penetrate lung tissue. While accepting that diesel engines are more efficient than petrol engines, we have to be mindful of any health issues.

In previous times during studies it was suggested that the average diesel engine emits soot that would be the equivalent of a sugar lump sized mass for every kilometre travelled.

Imagine all those sugar lumps lying by the side of the road.

John

[Freshacre]

Hagattd,

In 1970, you could not stand on the street in Chicago without your eyes watering from the car exhausts. Today you can.

Learn to accept it and enjoy the benefits.

Mind you - if you saw the documentary on Chicago recently - you'd weep for the place. Almost completely reclaimed by the tumbling tumbleweed, and the prairie.

So sad - and such an indictment of man's love affair with the motor car. Absolute devastation.

[Stuart_J]

Hagattd,.

In 1970, you could not stand on the street in Chicago without your eyes watering from the car exhausts. Today you can.

Tears of joy at the glorious sound of all those V8's

[Lady Penelope]

But are the tears really Acid Rain

[Agerbundsen]

Tears of joy at the glorious sound of all those V8's

I gotta admit the I sometimes pine for the old Chevy Big Block with 4-bolt mains that I breatherd a little on with a 650 cfm doule pumper Holley, headers, manifold and high -lift cam plus a few sundry updates. Docile as a lamb - till you put your foot in it. Never had it on a dyno, but guessd at around 450 HP. 12 mpg (UK) towing a 26 foot van trailer at 70 mph. Yes that was legal speed at the time.

Car was a Chevy Suburban. Petrol was $0.33/UK gallon. CO2 and Hydrocarbon emissions were probably horrible, but nobody talked about it.

[Agerbundsen]

Mind you - if you saw the documentary on Chicago recently - you'd weep for the place. Almost completely reclaimed by the tumbling tumbleweed, and the prairie.

So sad - and such an indictment of man's love affair with the motor car. Absolute devastation.

Chicagio was an interesting place back then. "The City that Worked" or like Hizzonor, the Old mayor Daley was quoted to say: " vote early, and vote often!"

Always made sure to have a $20 bill folde in your driving license, just in case you got stopped.

[haggettd]

This is an interesting thread indeed.

Abergundsen, I have no argument at all with the way that the environment has been obviously cleaned up and that we, and nature

benefit as a result.

My overall point is that I, one of the 'vocal minority', have been adversely affected by problems associated purely and simply with

the DPF fitted to my previous car.

The problems the car exhibited cost me a lot of time with repeated dealer visits, independent diagnostics costs and countless phone calls.

I had to pay higher road tax because the DPF equipped car emitted more CO2 than the non DPF car.

I was not informed the car had a DPF before I bought it (secondhand) and didn't even know that Mercs had them even as an option in the

first place. Had I known, I would have chosen a Merc without one.

All improvement means change but not all change means improvement.

I cannot argue that DPFs don't work because they do, however, I think that DPFs are a rather crude means of achieving the goal.

Soot collected in the DPF is a result of incomplete combustion of fuel which is in turn caused by too much fuel mixed with not enough air.

This is the root cause of the problem and I think that more effort should be made to tackle that up front issue.

It is an irony don't you think, that the place where a DPF is needed most is in the city, and the city is the environment least suited to it?

[Llanigraham]

haggettd,

I don't know how old your Merc was and how sophisticated the DPF was, but on both of my Freelanders I have never noticed that much difference in fuel consumption when the DPF has gone through a "cleanse", only a slight extra burnt diesel smell. You state a life of 100k miles, but I know people who have gone well over that and are still running with the same DPF. In fact LR do not give a life expectancy. Perhaps I'm lucky that I do a good 48 mile drive to work each day, with no traffic to speak of, so everything gets nice and warm.

As I siad there is a lot of "guff" being talked about these, just as there was about "cats" when they were first introduced. Who remembers the scares of:

If you drive through deep water you will kill the cat?

If you drive over rough roads you will kill the cat?

Cats will have to be replaced every 3 years!!

All these were scares in the motoring press at the time. How many are true?

[Agerbundsen]

This is an interesting thread indeed.

It is an irony don't you think, that the place where a DPF is needed most is in the city, and the city is the environment least suited to it?

I agree the the subject is interesting and with a high power diesel, which in my situation gets relatively many short trips, it is naturally a concern. If I lived in a big city, the engine choice would clearly have been inappropriate - but I do not. 50% or so of my driving is high speed on motorways, but the rest is tootling as Lady P. would have said. For the high speed, the 170 is just about perfect. had that component not been there, a lower power diesler or even (wash my mouth with soap and water!!) the 1.2 TSI.

The engine management does do a good job of providing both power and economy. I do not think this is possible without generating soot when yo need the power - hence the end-of-pipe DPF.

The cities need both low CO2 and other emissions, which favor diesel over petrol, so DPF is a necessity. Petrol is a dirtier engine than a similar hp diesel with DPF.

I am not up to speed on the current London Cab technology, but I suppose these are equipped with small enough engines to suit the slow speed environment and work OK -but you would not pick one for motorway runs, would you.

Anyway, am sorry you had unfortunate experiences with the Merc. I am not really concerned over the DPF in the Yeti. Latly, I am very happy that different strongly felt opinions can be discussed in the Forum in a civilized manner to benefit for all.

Have a nice Easter.

[haggettd]

haggettd,

I don't know how old your Merc was and how sophisticated the DPF was, but on both of my Freelanders I have never noticed that much difference in fuel consumption when the DPF has gone through a "cleanse", only a slight extra burnt diesel smell. You state a life of 100k miles, but I know people who have gone well over that and are still running with the same DPF. In fact LR do not give a life expectancy. Perhaps I'm lucky that I do a good 48 mile drive to work each day, with no traffic to speak of, so everything gets nice and warm.

As I siad there is a lot of "guff" being talked about these, just as there was about "cats" when they were first introduced. Who remembers the scares of:

If you drive through deep water you will kill the cat?

If you drive over rough roads you will kill the cat?

Cats will have to be replaced every 3 years!!

All these were scares in the motoring press at the time. How many are true?

Hi Llanigraham.

My Merc was an 05 facelift with just 67,000 miles and I was its second owner. It was with me for just 7 months.

The DPF system was one which did not use fuel additives but used Engine parameter controls to invoke a regen.

According to the VAG technology website "The latest generation of filters operate without additives."

So the Merc was latest generation design.

Whilst am very happy to hear that your DPF's lasted well I would not be too surprised that they did given that your journey

to work and back was optimum for DPF operation.

My journey to and from work was also ideal at 72 miles each way. Trouble was, my DPF was clogged with ash and beyond

recovery because I didn't drive the initial 67,000 miles.

A lot of the "Guff" that is mentioned about DPFs comes from the first hand experiences of owners - not the sensationalist press.

The only people to complain about DPFs are those that have had an actual problem with them.

Catalytic converters did have some of the problems you mentioned when first introduced - it was new technology after all.

Manufacturers have developed and improved over the years the way they mount and protect them.

They are freer flowing and less prone to overheating now that cars have accurate fuel metering methods (Fuel injection).

Remember, Cats were introduced 35 years ago and were used on cars with carburettors and not fuel injection.

When DPFs can do their job without affecting where or how you drive then I won't mind having a diesel car with one.

Fact is, they're not there yet.

[Stuart_J]

Having had bad experiences with a dpf on the Mk1 Superb I have to say Im less than convinced. The car failed on a decent of Mt Ventoux in France, clearly the car wasnt under load but where do you find somewhere to cruise at the 40-50 mph for 10 mins amongst all the hairpin bends, needless to say the car went from warning lights into limp mode & I then had to endure a week whilst the AA & Skoda France tried to sort it !! All it needed was a forced regeneration but thats another story

The other point thats slightly annoying is the dpf reduces mpg. From the old 130 superb without dpf which could easily average 50 mpg was replaced with the 140 dpf version that was never able to average much more than 40. A good comparison as car weight & body shape are the same

Cars like the superb run different cams to extend the time fuel is injected to raise exhaust temps, it adds to the "fire in the exhaust" but uses more fuel. Add to that you cant run them on full Bio Diesel as any Diesel not burnt washes down the bores & mixes with the engine oil, were it mineral oil it wont do much harm but bio diesel breaks down the engine oil, With a percentage of Bio being added to almost all diesel now it will be interesting to see if the current Diesel Engines last as long or if bearing failure etc becomes aproblem. If Diesel becomes more Bio it can only get worse

Overall I think the DPF is the best panic reaction the manufactureres can come up with to keep current engine designs running within the new eco warriors legislation & hopefully as the technology develops like all things it will become refined & reliable.

Thankfully many people are finding ways of removing them when they become troublesome

Edited 31 March, 2010 by Stuart_J

[haggettd]

Sums up my opinion Stuart J. Thanks

[aerofurb]

4500 miles now under the paws of my YETI and not one noticeable regeneration so far - 50/50 queuing traffic and reasonable speed. I personally think that there's a certain amount of old wives tales hanging on from earlier 'Mk1' DPFs.

Perhaps I'll be proven wrong but if you're considering buying a YETI and are concerned about DPF issues on the CR engine - don't be.

It seems to be that those of us that are actually owning and operating DPF-equipped YETIs don't have a problem whilst people who don't own or drive them, do....

[haggettd]

4500 miles now under the paws of my YETI and not one noticeable regeneration so far - 50/50 queuing traffic and reasonable speed. I personally think that there's a certain amount of old wives tales hanging on from earlier 'Mk1' DPFs.

Perhaps I'll be proven wrong but if you're considering buying a YETI and are concerned about DPF issues on the CR engine - don't be.

It seems to be that those of us that are actually owning and operating DPF-equipped YETIs don't have a problem whilst people who don't own or drive them, do....

I'm sure all of those who have new DPF equipped cars will encounter no problems whatsoever. I have more concerns for the future second

and third owners - those who buy cars at 60,000 plus who have no idea about its previous life. They are the ones who are more

likely to have the problems and expense.

No Yeti owners have achieved that sort of mileage yet so we'll just have to sit back and wait a few years to get a better picture.

After my DPF was replaced in my merc at 67k and the differential pressure was replaced and the ECU re-flashed it gave no trouble

over the next 15,000 miles. I couldn't wait to get rid though and am more than happy with my new 1.2TSi

The Yeti is simply a nicer car to travel in and more satisfying to drive.

[Agerbundsen]

I guess that ends that discussion for now. I am also sure that if anybody gets a DPF problem in future, we will hear about it.

BTW, I was at the dealer yesterday, just to get a free cup of coffee. They had just received the first 1.2 TSI as a demo and were wildly impressed with it.