DPF Filters - Just how bad are they? - Simmo1111

Having read the horror stories about particulate filters, I have at this point resigned myself to avoiding an SUV fitted with a DPF and am looking to purchase a Honda CRV 2.0 petrol 4WD. (4WD will suit my purpose better than a 2WD due to some of the places I park) My budget is around 11.5K. (I am aware that a pre 2010 CRV 2.2iCDTI doesn't have a DPF but I don't want to fork out 10K plus for what is , in effect, an old car.) I started out with quite a good range of choices when I was looking for a diesel such as the Mitsubishi Outlander, Nissan X-Trail, Ford Kuga and also a Honda CRV diesel but after reading about the perils of a DPF when journeys are quite short, I decided that I needed to avoid anything with one fitted. This has obviously reduced my options by quite a lot and I'm now going to have to pay the price in fuel costs.

I was just wondering whether I'm being too paranoid about having a 4WD with a DPF or are they actually as bad as they appear to be?

My annual mileage will be around 11K and a good 90% of it will be short trips of maybe 20 miles or so. As in 10 miles each way. Obviously this is going to begin to clog up a DPF pretty quickly. But .. It's also going to cost me a fair chunk of cash in fuel if I choose to run a 2.0 a CRV petrol though.

I get the impresssion that I would need to take the car (assuming I was to buy a DPF diesel of course) for a good blast up the motorway in order to give the DPF chance to clear (which is fine so long as it's guaranteed to do the trick) but does anyone have any clue with regard to how often and how long for? i.e. would I need to do it every week/2 weeks/monthly or what? (or does it depend on the model of car in question/ the distances I drive?

Providing I know what I would need to do in order to keep a DPF 'happy' then so long as it doesn't involve doing anything ridiculous like belting up the M1 in second gear for 50 miles every week then I might reconsider my options.

Any advice would be very welcome before I take the plunge into running an expensive petrol engine.

DPF Filters - Just how bad are they? - Gibbo_Wirral

A quick run up the motorway isn't an effective solution, long term. You're just going to waste time and money on fuel. And that's assuming the car will actually regenerate on command (i.e. being on the motorway).

Its like having a diet coke with a KFC family bucket.

Another thing to consider is how long you're planning to keep the car, and how the previous owner drove it. I've known lots of DPF problems with diesel cars on their second owner, the first owner has got rid before the blocked filter is apparent.

Just bite the bullet and go for petrol. Yes, you'll pay more in the short term, but once you factor in a replacement DPF and additive (if it uses it), the time off the road, the other knock on effects from a blocked DPF, and it will be worth it.

DPF Filters - Just how bad are they? - Simmo1111

All helpful and sensible points. Cheers Gibbo.

DPF Filters - Just how bad are they? - Ethan Edwards

My 2012 Qq has one. So far so good as it's doing 75miles a day at m way speeds. Even so it's one thing I wish it didn't have.

Edited by Ethan Edwards on 08/02/2017 at 14:03

DPF Filters - Just how bad are they? - Bladerrw

I've had a diesel for 3.5 years and 38k miles (mixed town and motorway).

I reckon I'm over £2,600 better off so far on fuel and tax alone, compared with where I would be if I had bought a similar petrol version of my car.

Worst case is I have to replace the DPF tomorrow and I'd still be up a £1k.

DPF Filters - Just how bad are they? - SLO76
As a rough figure the difference between the MK III 2.2 diesel CRV and a MK IV 2.0 petrol that fit within your budget and both equipped with 4wd is around 5mpg according to HJ's real economy figures which at current prices won't even save you £300 a year or just over £5 a week.

Factor in that the petrol will be a newer mechanically less complex car with lower mileage and it's highly unlikely you'll save a penny by opting for diesel in this case anyway. The 2.2 diesel is good but they do eventually suffer issues such as gummed up EGR valves and turbo failure while the petrol really is next to bombproof with no real weaknesses if it's serviced regularly.

If you could live with 2wd then the 2.0 petrol MK IV is even closer to the diesel economy figure so unless you're prepared to up the budget, live without 4wd and go for the excellent (but still DPF equipped) 1.6 DTEC which will break 60mpg on a run then I'd go for the petrol.
DPF Filters - Just how bad are they? - Simmo1111

Thanks very much SL076, very helpful as usual.

The one I'm looking at is here.

www.autotrader.co.uk/classified/advert/20151204921...1

My only concern is that I hear that the petrol engine isn't particularly strong and this one obviously has a towbar fitted. Anything I should look for i.e clutch issues etc?

Thanks again.

DPF Filters - Just how bad are they? - Bladerrw

I've always thought that V-Tec engine is very reliable. Looks like a good car.

DPF Filters - Just how bad are they? - Brit_in_Germany

I've always thought that V-Tec engine is very reliable. Looks like a good car.

Apart from the fact it hasn't moved since May 2016.

DPF Filters - Just how bad are they? - Simmo1111

That's an interesting point Brit_in_Germany ..

How can you tell, am I missing something on the advert?

DPF Filters - Just how bad are they? - RobJP

Right. Some useful tools for you for your search :

Car tax check. You can see when car tax on a car ran out - which tells you how long it's been off the road for.

vehicleenquiry.service.gov.uk/

Tax on this car ran out in October 2015, thats 16 months ago. So it's been 'in the trade' and sittinmg on a forecourt since then.

MOT history site. So much information is available here :

www.check-mot.service.gov.uk/

From this, you can see that it was first MOTd in Sept 2015, approaching 3 years old. That MOT then expired in October 2016, and was allowed to expire.

It then continued to sit on a forecourt for another 6 months until it was MOT'd in May 2016. Since then it has done one (yes, one) mile according to the autotrader advert.

So that confirms the car tax - it's been sitting around pretty much since it passed it's MOT in October 2015.

DPF Filters - Just how bad are they? - SLO76
It could have been a perfectly good car that's been traded in at a dealer then priced wrong or just struggled to find a buyer then punted to auction as overage stock as per some dealers policy but I suspect it's likely it has something more worrying in its past such as poorly repaired crash damage which would explain the failure to find a home.

The only time we sent anything like this through the ring was again mostly down to poor paintwork repairs that would cost too much to put right or possibly a mileage discrepancy. Be interesting to go take a peek, see if you can spot what it is.
DPF Filters - Just how bad are they? - SLO76
The best cars are snapped up by Honda dealers who can sell all they can get their hands on. There are also some good examples at other main dealers who've taken them as part exchanges but smaller used only dealers like this will have sourced this car at auction which means it will have been traded in elsewhere but not been up to their standards and sent to auction.

No one sends stock to auction unless it's either too old to retail (not the case here) or has mechanical or paintwork issues that would be too costly to rectify properly. Thus the reason why almost every car I'm asked to look at with one of these small places tends to have had poor quality paint usually done by themselves or a small local body shop on the cheap which will get tatty very quickly.

A quick search on the company pulls up a fair number of unpleasant customer reviews and some strange information on the company accounts, directors names changing regularly etc so I don't have much faith in this particular car despite the quality pictures and description. Be wary of faked service histories, sadly another common issue with back street fly guys. Call the servicing dealer who's stamped the book and ask if they move ever seen the car, I told a customer to do this on a BMW recently and said dealer had no record of it, I knew it hadn't been regularly serviced just by looking at it.

I'd sooner travel a bit further and spend a bit more upfront and visit these guys who've two or three you might be interested in. Approved used Honda warranty is vastly superior to what dodgy Joe (or dodgy Zaid El-wadi in this case) will offer. Auto Trader #DrivenByMe
www.autotrader.co.uk/classified/advert/20170202190...5


Auto Trader #DrivenByMe
www.autotrader.co.uk/classified/advert/20170124160...2

Auto Trader #DrivenByMe
www.autotrader.co.uk/classified/advert/20170112122...8 at another main dealer...

Edited by SLO76 on 08/02/2017 at 15:25

DPF Filters - Just how bad are they? - Simmo1111
Excellent stuff..
As usual I'm glad I took the time to come here again before splashing my cash on anything. Thanks very much for your help chaps.

I hate buying cars ....
DPF Filters - Just how bad are they? - Stumblebum

A tow bar may be used for a bike carrier. I have a tow bar mounted bike carrier for my petrol Civic. Tow bar mounted carriers are far easier to load o/off 3 bikes complared to roof mounted. Also a lot of car parks have height restrictors.

It could also be used for a light trailer to take garden refuse to the dump (and keep the car clean).

DPF Filters - Just how bad are they? - craig-pd130

My last three cars have had DPFs, and I've had no problems with any of them, even though my driving patterns should not suit DPFs (a 3.5 mile commute to work, 70% of my driving is trips of less than 10 miles, etc).

However, as they've all been company cars that go back after 3 years and 30-odd thousand miles, I shouldn't really be experiencing problems anyway. I can't comment on the long-term ownership implications.

DPF Filters - Just how bad are they? - RichardW

I've got 2 - both the much maligned PSA 1.6 16V HDi....!

C4 Picasso bought at 48k, now on 102k. Had to refill the fluid at 95k. Gets used mostly around town, although we live in a small country town, so it gets out for 10-15 miles most weeks; also used for family trips mostly. Had the warning on that regen was not completed a couple of times, but a 10mile trip clears it.

307 bought at 80k, now a 125k. Fluid was done before I bought it. Mostly used for 30mile cross country commute. Not seen the warning light. Fuel economy has dropped off in the last 10k miles, so I am going to take the filter off and clean it later in the year when I do the cambelt (rad needs to come out to get the filter off, so might as well combine it with the cooling system being drained down for the water pump).

Both regen at around 300 mile intervals - you can tell they are doing it if it's wet as the HRW comes on. Both will regen when just tootling about on the country roads, driving normally - no need to thrash it - takes about 10 miles. Both still have virtually clean tail pipes.

Diesel related expenditure has only been new injector seals on both, with the C4 needing a replacement injector as one didn't like being taken out. The C4 had to have a new turbo at 70k, but that is well known about on this engine! 307 has avoided this as I removed the filter from the feed pipe. C4 had a new clutch at 90k - failure was the release bearing, so not diesel related.

Across the 2 cars diesel is saving somewhere north of £1000 a year, so saved about £7k over the lifetime over having petrols, against an expenditure of a bit over £1k for the turbo and injectors - I won't be hesitating to replace them with diesels - probably, if I can get another 3 years out of them, with E6 cars.
DPF Filters - Just how bad are they? - Steveieb
There is obviously a demand to remove these wretched things as we have a company in my town that will remove the DPF and remap the ECU to look like it's still there.At £330 it's cheaper than replacing the Dpf.
They use a disc cutter to slice open the box and replace the Dpf with a piece of pipe.
Simple alternative is to avoid anything fitted with one by buying an older model and spending some money on refurbishing it.
This is what seems to happening to the non lease van market.
DPF Filters - Just how bad are they? - RT
There is obviously a demand to remove these wretched things as we have a company in my town that will remove the DPF and remap the ECU to look like it's still there.At £330 it's cheaper than replacing the Dpf. They use a disc cutter to slice open the box and replace the Dpf with a piece of pipe. Simple alternative is to avoid anything fitted with one by buying an older model and spending some money on refurbishing it. This is what seems to happening to the non lease van market.

That should fail the MoT on a simple visual check.

DPF Filters - Just how bad are they? - daveyjp
Speaking to a colleague today who has a 5 year old 3 series, 70,000 miles. DPF light flagged and refused to extinguish. Full BMW diagnostic highlighted an issue with two sensors which form part of the system.

Parts were £140 each and as these sensors may have failed at some unknown time in the past the DPF could be cooked, hence the warning. He was waiting for a call on how much it could cost.

He was also warned the sensors are a nightmare to remove and if either of them breaks in situ he can add a new exhaust.
DPF Filters - Just how bad are they? - gordonbennet

That should fail the MoT on a simple visual check.

I suspect the straight pipe is welded inside the empty DPF canister which is then re-welded up to make it all look the part.

Well that's what i would do, and probably stuff some steel mesh in the void between pipe and canister wall to make it sound not quite so hollow.

Interesting the post from RichardW above, despite French cars getting lots of flak, it would appear that so long as you keep the EOLYS fluid topped up as and when that these Pug/Cit systems are less troublesome than many others, able to regenerate reliably in quite short order.

DPF Filters - Just how bad are they? - expat

Halfords claim to be able to clean clogged DPF. I don't know how they do it but if you are looking at a huge bill to replace one then it might be worth checking them out.

www.halfordsautocentres.com/advice/car-care-advice...s

I expect it is a bit more sophisticated than pouring in hot caustic soda as used to be done with two stroke motorcycle silencers that clogged up with carbon.

DPF Filters - Just how bad are they? - craig-pd130
Both regen at around 300 mile intervals - you can tell they are doing it if it's wet as the HRW comes on. Both will regen when just tootling about on the country roads, driving normally - no need to thrash it - takes about 10 miles.

Funny you should mention that: when my 2008 Mondeo IV TDCI used to do its regular active regeneration (about every 400 - 500 miles), the heated rear window would automatically come on, and I believe the aircon pump would switch on too if it wasn't already engaged.

Must be something to do with putting extra load on the engine to heat up the DPF to soot-burning temperature. Neither of my Volvos does this, however, so it must be a peculiarity of the Peugeot-Citroen-Ford diesels ....

DPF Filters - Just how bad are they? - gordonbennet

I'll just slip this in here.

Some of our new euro 6 lorries have DPF condition on the menu, which the driver can call up, and can if conditions are right manually trigger a regen.

If cars had this facility, at least for those who have a clue where the bonnet pull is, then it would make living with the things easier.

One buys a Diesel to save fuel, but then having to regularly drive nowhere in the vain hope it might actually regen, or might not, or might decide (undected) to regen half a mile from home, is lunacy.

DPF Filters - Just how bad are they? - RobJP

I'll just slip this in here.

Some of our new euro 6 lorries have DPF condition on the menu, which the driver can call up, and can if conditions are right manually trigger a regen.

If cars had this facility, at least for those who have a clue where the bonnet pull is, then it would make living with the things easier.

One buys a Diesel to save fuel, but then having to regularly drive nowhere in the vain hope it might actually regen, or might not, or might decide (undected) to regen half a mile from home, is lunacy.

I think we've had this discussion before, haven't we.

Most of Joe Public have absolutely no interest in how a car works. Hell, most people lease or PCP cars, run them for 2-3 years, then get another one. As you yourself say, a lot of them would struggle to open the bonnet. Regular (or even occasional !) checks of tyre pressures, oil level, coolant, etc are not something that many people seem to do. As long as they get in it and it starts and drives, they couldn't care less.

I know of 2 cases where people have wrecked engines by completely ignoring the RED oil light on cars. One of those people even said "oh yes, that light has been on a while", or words to that extent.

I'm constantly surprised just how oblivious to the world around them most people are.

DPF Filters - Just how bad are they? - skidpan

One buys a Diesel to save fuel, but then having to regularly drive nowhere in the vain hope it might actually regen, or might not, or might decide (undected) to regen half a mile from home, is lunacy.

Despite having had 2 diesels with DPF's and having had no issues this is exactly what persuaded us to buy petrols this time, this and the fact modern turbo/supercharged petrols are nearly as economical as diesels with similar (or better from our experience) easy going driving manners.

The BMW we had was not too bad really, if you stopped mid regen it restarted the next time you drove once the temps were up. Over 5 1/2 years an 37,000 miles we has not a single issue. If I could be sure current BMW's are the same I could have been tempted to get another this time but without a very long test drive there is no way of knowing. The diesel BMW saved me about £3000 over those 5 /12 years when you consider fuel and depreciation, more than enough to replace a DPF.

But the Kia we had was a bit of a pain. In 5 years and 38,000 miles we had no issues but if you switched off mid regen it would wait a seemingly random distance before restarting and that would always seem to have been inconveninet again. So to ensure it finished you would continue your journey which would waste time and diesel. Over the time we had it I guess we saved about £2000 so happy there but not with the way it was set up.

I told the Kia service manager we needed a warning light or gauge to inform us about DPF health and he agreed. But he added that it would be a waste of time since 99% of owners ignored lights and gauges. He suggested a spike in the centre of the steering wheel instead of the airbag to inform drivers who carry on driving regardless about the error of their ways.

But there is one simple fact, just going out for a drive to regen the DPF will achieve nothing unless one is due. Again, you will simply waste time and diesel.

DPF Filters - Just how bad are they? - craig-pd130

The BMW we had was not too bad really, if you stopped mid regen it restarted the next time you drove once the temps were up. Over 5 1/2 years an 37,000 miles we has not a single issue.

My Mondeo was like your BMW - regens were relatively quick (never more than 10 minutes in duration) but always noticeable, the engine sounded dog-rough while regenning. However, both the Volvos I've had since have long regen cycles - up to 20 minutes or more - although they seem gentler and according to the instant mpg read-out, use less fuel than the Mondeo's regen cycle.

I quickly got bored of waiting for Volvo regens to finish, and have ignored them for the past several years (switching off mid-cycle etc), with no apparent negative effect on the car.

DPF Filters - Just how bad are they? - RT

I'll just slip this in here.

Some of our new euro 6 lorries have DPF condition on the menu, which the driver can call up, and can if conditions are right manually trigger a regen.

If cars had this facility, at least for those who have a clue where the bonnet pull is, then it would make living with the things easier.

One buys a Diesel to save fuel, but then having to regularly drive nowhere in the vain hope it might actually regen, or might not, or might decide (undected) to regen half a mile from home, is lunacy.

It's annoying - I'm anorak enough to check that from time to time - but can't without expensive diagnostic equipment - nor can I access the % contents of the adblue tank left, both of which are available to the car's ECU

DPF Filters - Just how bad are they? - RT

My first diesel was a DPF-equipped Euro 5 Hyundai Santa Fe which did 54,000 miles before I sold it - not once could I detect anything that felt different enough to be a regen taking place - the only time it worked hard was towing a caravan but that was less than 10% of the mileage covered.

My present diesel is a DPF/SCR-equipped Euro 6 VW Touareg which has done 12,000 miles and like the Hyundai, I've never noticed a regen taking place.

I don't know if dealer diagnostics showed the DPF % full but I was never informed of it and never had any issues, despite short winter trips for half the year.

DPF Filters - Just how bad are they? - skidpan

My first diesel was a DPF-equipped Euro 5 Hyundai Santa Fe which did 54,000 miles before I sold it - not once could I detect anything that felt different enough to be a regen taking place

With both the BMW (Euro 4) and the Kia (Euro 5) it was easy enough to spot when a regen was taking place, to be honest even the wife could spot it. The engine note changed slightly when driving and when idling the revs were higher and the engine louder. When you suspected a regen it was easy enough to swap the mpg display to instant which would show a figure nearer 30 mpg instead of the normal 55 mpg at a 70 mph cruise. If you got out of the car when it was regening there would be a smell of burning from the windscreen scuttle, in summer with the windows open it would spread to the inside of the car. If you put your hand near the tailpipe (dont touch it) it would be litterally red hot instead of the normal cool you get with diesels.

DPF Filters - Just how bad are they? - Theophilus

"Just how bad are they?" ... aren't we in danger of losing sight of the purpose of making DPFs mandatory ... to reduce the quantity of toxic particulates being pumped out by our vehicles (yes, I've a diesel!) into the atmosphere.

So ... they might be "bad" for our wallets, but surely we can agree they are good for our children & grandchildren's health, bite the bullet and live with the motoring consequences.

DPF Filters - Just how bad are they? - RT

"Just how bad are they?" ... aren't we in danger of losing sight of the purpose of making DPFs mandatory ... to reduce the quantity of toxic particulates being pumped out by our vehicles (yes, I've a diesel!) into the atmosphere.

So ... they might be "bad" for our wallets, but surely we can agree they are good for our children & grandchildren's health, bite the bullet and live with the motoring consequences.

They're for all generation's health, not just the future generations - particulates cause cancer and lung disorders.

As someone in long-term cancer remission and recently diagnosed with asthma and COPD, I'm all for DPFs - and I too drive a diesel.

DPF Filters - Just how bad are they? - Chris James

I don't think that anybody is against DPF's and what they do, but because they are so vital then surely they should be fit for purpose and last the life of the other major components on the car, as well as being suited to the roads and driving environment often found in the UK - i.e endless roadworks, stop start traffic and 20mph zones. In the U.S all major emissions components on cars made after 1996 are covered by an 8 year / 80,000 miles warranty called The Federal Emissions Warranty, so if a major emissions component ,which is legally required to be working fails then it gets replaced by the dealer Free of Charge, even if outside of the original manufacturers warranty, provided its on the list of covered components and meets the age and mileage criteria and has been serviced.

It seems that, as consumers, we should be demanding similar safeguards, especially if more and more bolt on emissions controlling components (no doubt, each with varying degrees of reliability) become the norm, and legally required. At the end of the day if the manufacturers don't have the confidence to put a reasonable Warranty on the longevity of the DPF, then they shouldn't be fitting them until such a time where they do have the confidence.

At the moment, (reading the Toyota UK blog as one example) Manufacturers don't even seem to be covering or honouring DPF problems even as part of the normal Warranty, preferring to wave the "Driving Style" card as a get out clause. Suffice to say that whilst there are people with diesels who do low annual mileages and regular short journeys and who do contribute to or cause their own DPF problems, however there are also more than a fair scattering of daily motorway drivers and those covering large annual mileages on the various owners' forums who also have had expensive problems. But I guess whilst Manufacturers continue to blame the Consumers for these expensive problems, and expect the Consumer to also foot the bill for it, even when it occurs during the normal Warranty period, then its a win-win for them, and why would they be looking at spending large amounts of money in R&D to improve the technology, there is no reason or incentive too, because they aren't the ones who are out of pocket.

It also begs the question as to why Manufacturers don't fit a basic warning light to the dash board which lights when a regeneration cycle begins, so once started the driver at least has the option to extend their journey until it completes, rather than 'guessing' when the next regeneration is due and hoping to time their next 20 minute traffic free, steady speed journey with a Regeneration attempt based on mileage alone, whilst listening out for noises or smells to confirm it is regenerating!. It's laughable, in an era when we are encouraged to use our cars less, and to not make needless journeys in order to preserve the dwinding oil resources that a growing number of people are actually driving up and down the motorway or dual carriageways for no other purposes than to enable the "green" parts of their car to service themselves.

If similarly expensive Cambelt and Gearbox failures were as prevalent as DPF problems have been over the last several years on some models, there would be an outcry, yet it seems when somebody uses that magic and emotive word "emissions" it all suddenly becomes an acceptable cost, even when those costs are frequently being levied back on the consumer. Ludicrous!.

Edited by Chris James on 13/02/2017 at 21:06

DPF Filters - Just how bad are they? - gordonbennet

All fair points CJ and an excellent post, but in practice warranties and proven durability, even class leadinggenuine customer care, don't actually sell that many cars, or quite simply those makers who provide 3 years measly cover and make cars of dubious reliability/durability would have ghost showrooms, whilst those who provide 5 or even 7 year warranties and look after their customers would be running 24/7/365 shifts to try and keep up with the sensible buyers.

Up to a point lease and company car purchases, and to a lesser extent cars on PCP deals, make up the vast majority of new car sales, but not all, i'm sure we all have friends who, despite having lots of repeat trouble with previous purchases of certain shall we say fashionable makes, to the extent they dare not own the cars longer than the 3 years they are warranted, stubbornly go back and buy the same brands again and again.

Increasingly i find meself at a loss to know what makes these people tick.

Edited by gordonbennet on 13/02/2017 at 21:48

DPF Filters - Just how bad are they? - expat

The solution to getting rid of diesel particulates but keeping good economy is LPG. Putting a petrol vehicle onto gas means you don't have particulates in fact the exhaust is clean enough to be run indoors and in mines. It is also is a much cheaper fuel at least here in Australia. It does have its own problems mainly another tank taking up some of the boot but it does work well and I have been running it for ten years with no problems. It also is better for your engine. My oil stays clean and honey coloured right up to when it gets changed. If you are doing big enough mileage to pay off the initial installation costs then it is a solution worth investigating.

 

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