MOT test fail for DPF removal

MOT test fail for DPF removal
5 Dec, 2013 6:11pm Chris Ebbs

Diesel particulate filter check will now be part of the stricter MOT test

The MOT test for diesel cars will be tightened up from February 2014 and any car that is missing a diesel particulate filter (DPF) once fitted as standard will fail.

Currently a car is only tested on the emissions, and not if it has a DPF still attached. However, this will change with garages and testing centres now required to check that the part is still present.

Companies across the UK offer to remove the DPF for motorists in a bid to avoid costly repairs. The filter has to be regularly regenerated to burn off soot that builds up over time by driving the car up to 40mph for more than 10 minutes – often done on motorway journeys.

However, if this isn’t done then it can lead to the filter becoming clogged with prices for a new part costing upwards of £1,000. In order to avoid such problems, some drivers will get the part removed.

This practice has always been illegal, contravening the Road Vehicles (Construction and Use) Regulation 61 A as it no longer meets emission standards applied to it when new, but companies continue to advertise the practice.

Roads Minister Robert Goodwill said: “I am very concerned that vehicles are being modified in a way that is clearly detrimental to people’s health and undoes the hard work car manufacturers have taken to improve emissions standards.

“This change to the MOT tests makes it clear – if you have this filter removed from your car it will fail the test.”

A spokesman from the Department for Transport told us that anyone that has had the filter removed, will now have to a new one put back on their car in order to pass their next MOT test.

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So, here's a component that lasts 75-100K miles, if used correctly, costs £1000 or more to replace, and must be there to pass an MOT.

Remind me, why are diesels still so popular?

DPF's are a complete con, any saving in emmisions is wiped out when you have to thrash the bloody thing up and down the motorway for no other reason than to trigger a regen. That's before you even consider the environmental impact of replacing the thing when it inevitably fails, or the poorer fuel economy they give.

Fuel Economy,is one of the reasons, and also long levity of components.

My mothers 12 yr old VW Lupo Sdi, is still on its original exhaust, and the only component to have been changed in all those years,is one noisy rear wheel bearing, every other mechanical component is original.

After 96576 trouble free miles,the Lupo is still in great shape.

Compare that to a petrol vehicle of similar age and mileage.

"This practice has always been illegal, contravening the Road Vehicles (Construction and Use) Regulation 61 A"
C&UR only apply to new vehicles, not to ones that are already in service. I doubt many >3 year old vehicles meet the emission standards of when they were new and are not tested for that in any case.

Are you saying petrols can't last beyond 96k miles?

My mate had a Mazda 6, had to pay £1000 to get the DPF replaced and it lasted a year before going again. He sold it and got a petrol.

We've had to have the DPF replaced on our Ford C-Max twice. Once when 2 years old and again recently at 4 years old. Despite the car being under warranty the first time it appears that teh DPF is excluded from the warranty (Because they know its expensive and likely to fail). We drive the car property and commute 20 miles each way on a daily basis, so not lots of short journeys. It appears that DPF technology just isn't ready yet, and instead of addressing the actual problem the new rules just make one of the workarounds illegal.

At last someone wakes up and imposes the law on DPF that should have been done when the law was introduced. I suspect a large number of motorists are involved in this ill practice.
And I wonder how many countless million soot and hydrocarbon particles escaped into our atmosphere while our elected leaders slumbered?

People take them off because they are a nightmare, and a direct result of EU/UK politicians not giving a damn about the man on the street. I have a deisel company car, but the wifes private car will always be a petrol

My Audi 80 Sport did 180k miles before I sold it on with no problems, and my Primera 2.0eGT was at 160k when sold on. Mechanical reliability is nonsense. Regular oil changes, and servicing makes the biggest difference

my past 5 cars have all been diesels, covered over 750,000 mile sin them, and never had to change a DPF. my current disel car does 0-60 in 5.2 secs, and averages 48 mpg, who wants petrol?

So diesel cars are not clean as manufacturers claim then ! i thought diesel cars meant to be cheap but appears the money saved on fuel is spent on other areas of the car !

Yes and that 12 year old Lupo doesn't have a DPF. Modern turbo diesels with DPF are massively less reliable than they used to be. People are now waking up to this and going back to buying Petrol as any saving you make in fuel costs is lost in higher purchase price then expensive repairs to DPF technology, not to mention 5p a litre more at the pump.

So what happens now if the DPF was not removed, but drilled through? There will no easy way to test its efficiency...

This is what a lot of people I know have been doing.

What's the exhaust and a wheel bearing got to do with your mum's diesel car's reliability? A petrol version could easily be the same. There's no way of knowing.

Absolutely, thats why I would never buy a diesel - heard of and read about so many issues with DPF which is why I would never touch a diesel car. And it seems to affect so many different models. I understand that some car salesmen are actually checking how you intend to use a potential (diesel car)purchase before they sell you one. ie. if you do a low mileage then buy a petrol.

How many of your past 5 cars had a DPF though? They are a relatively knew addition to Diesel cars.

I'll take a petrol thanks. Wouldn't touch any car with a tractor motor.

All bar one, i share them with my wife, and all have been used for business.

a 3.0 litre twin turbo, 335 hp is hardly a tractor motor. to get that power in petrol you would be lucky to get 25 mpg. no comparison

a quick calculation shows my current car at 150,000 miles at 48 mpg, has cost £20,500 in fuel, an equivalent petrol would be over £37,500, would pay for a few DPF, not that i have ever needed one.

Nothing like this topic to bring out the reactionaries!

My non DPF Diesel Skoda 2006 is up to 612,000kms, I will be changing next year and I am worried about the whole DPF thing, will be putting about 500,000kms on the new car.

When will average joe realise that modern diesels are no way as near as reliable or cheap to fix as there older cousins and any savings in fuel are often wiped out by one repair on any of the diesel engines unique componants.

Here is a list of stuff that is fitted to a modern diesel AND NOT A PETROL that now often fail before 100k and how much they cost to replace

DPF £1000
DMF and clutch £1000
TURBO £600 +
EGR valves £150 + ( yes petrols have these but diesel ones fail alot more often )
HIGH PRESSURE PUMP and fuel sysetem £3000 + to be fair these don't fail as much as the other itmes above, but often when they fail they require the entire fuel system to be replaced because of debris circulating in the system.

there are alot more parts to a modern diesel compared to older ones, and tons more than a petrol.

plus the fact that diesel servicing typically cost more than a petrol and the fact that diesels are more expensive to buy and the fuel costs more.

plus apart from VW'S tainted 1.4 TSI enginer modern petrols last just as long as modern diesels.

and to top all of that modern diesels are now starting to have NOX traps and urea injection systems added.

Rant over

As i have said 5 diesel cars 750,000 miles covered and none of the above have ever needed to be fixed or replaced, i drive Audi, guess you get what you pay for, if you go cheap. I will stick to diesel, may be the moral is to avoid, your ford, Vaux, renault etc


Correct. You only have to go on many car related forums to find threads about DPF removal. Some even remove the cat for goodness sake.

Some people are going to be in for a shock and if anyone is buying a secondhand diesel, Id suggest they do some research to find out if a DPF was and is still fitted to the car.

You seriously think a drilled through DPF will pass>

So you have 3.0 litre with twin turbos and all you can achieve is 0 - 60 in 5.2 seconds? Whats impressive about that?! There are many smaller capacity petrol motors that would manage that! - they would sound better and be a lot more fun to drive! Do F1 cars use diesel? No. Diesel engines belong in commercial vehicles!!!

Are you serious - Audi cars are hardly a paragon of reliability are they? Its often Audi's that lag at the bottom of reliability tables and I often see them sitting on hard shoulders. Ford and Vauxhall cars are every bit as well made and reliable - and thats not coming from someone who owns a car from these brands.

How do you know 'Dan the ex-mechanic man' is making reference to Ford, Vauxhall, Renault etc?! It could well be VAG products. In fact, if you read the comment he refers to 'tainted TSI' petrol engines which are also used in Audi! LOL!

well with 750k miles with no issues what so ever, i know what i will stick with. just have to look at residual values and lease costs, Audi cost less to lease becaue they have lower overall running costs. The cars mentioned here as having issues with DPFs, are Ford, Vaux, Mazda etc

And do 48 MPG, i think not, F1 doesn't use diesel, but Audi have won LeMans with diesels for several years. I have had no problems, so will support diesel from premier brands

I could lease and drive an Audi repmobile if I wanted but choose to drive something that stands out and really is top notch in terms of build and reliability unlike Audi, Merc etc which just pretend to be quality cars. VAG have a lot of issues with TSi engines and DSG transmissions.

and how much these dpf filters egr valves cost to produce in the first place time, materials, money, CO and other polluting gases generated in making them never mind owners grieve about reliability and costly repairs i'm mot tester and mechanic myself and as far as i can tell does't matter what make you drive they all more less the same apart from few exceptions and newer cars will be more complicated and there is more things to go wrong complexity also makes them more expensive to repair because main dealer is often an only option for repair they also have their good bits such as fuel economy, safety, comfort they extracting more power from smaller engines you can clearly see this in motor sport f1, wrc e.t.c. they produce less emissions at least when they are new so much lower road tax price as for now way forward is drive smaller cars if you can they less complicated and cheaper to repair until thigs improve if they ever will ???

How about we fix the whole design of DPF's first. There's clearly a problem with them if people are feeling forced to remove them. Thank christ I've got a petrol

Generally if you have a problem with your engine you take it to a garage and they fix the problem, I guess in most cases it's an easy fix if you remove the problem from the car or van, their fairly pointless if the soot is stored up and then spat out anyway just stored until you hit a certain speed, if I'm waiting traffic or at a crossing by turning the engine off is a better solution?

They won`t be able to establish if it is there or not. Usually it is inside of a filter which is removed therefore at first glance is going to look legit. Assuming that welding is not facing down but up.

Exactly. Google 'DPF Problems' to see how widespread the problems are, and across all manufacturers. The technology is clearly not lasting long and this is leading people to remove them rather than replace them every few years at a cost of £1000+.

Diesel engines used to be reliable, clocking up 300k - 500k+ easily using largely the same engine components which they left the factory with. These days the engines are still reliable, its just the additional bolt on's for pollution control which don't work properly (DPF's, EGR, Swirl Flaps etc) - google them, and you'll find they are ALL weak points on virtually all diesel cars.

If manufacturers are forced to fit these devices then they should be made to last the lifetime of the engine itself, if they don't then they shouldn't be fitted.

I had a Xantia, Omega, Cavalier and BMW, all dating back to the mid 90's and all were Turbo Diesels - Not one of them had a turbo failure. A Taxi firm whose owner I know also ran a fleet of Omega's for many years, starting originally with BMW 2.5 Diesels and later the 2.2 DTI's again not one suffered a turbo failure and the majority did well over 300k miles. But they were serviced well ahead of the manufacturers recommendations.

Luck? or 5k - 6k oil change intervals?. I personally think its down to extended oil changes of up to 15k or 20k miles which reduce the life of the turbo bearings and result in the instances of increasing numbers of owners reporting turbo failures. Put it this way, It rarely happened back in the 6k service days.

Most of the issues reported these days are down to DPF's, Swirl Flaps and EGR's which are all devices bolted on to reduce pollution or improve efficiency. So in my view diesel engines haven't become more unreliable, its just the later bits added to appease the Euro Brigade that make it appear that way.

I remember a time when an MOT was there to test the physical safety of a vehicle. Now they appear to exist to enforce the requirements of a few tree huggers

Anybody removing a DPF gambles getting a criminal record and a fine of up to £1500. Garage owner and driver

My current SAAB petrol is the higher-powered Aero version and gets used accordingly. It's now up to just under 140K. Still on its original exhaust and apart from routine service items and a couple of springs and the like, it's had no significant issues. Petrol vs diesel is not the issue it used to be. I know plenty of people who have had serious issues with diesel-powered stuff well under 100K, and similarly petrol stuff with problems. Dual-mass flywheels, etc. Choose the manufacturer rather than the power plant...

There is a simple way round this. you take your old dpf. weld a solid pipe though the middle of it. then stick it back on the car. From the outside it still is present. But it's just for looks

The soot isn't just spat out, it gets burned off when the DPF recycles.

DPF's have been fitted to cars since 2000, so well over 13 years ago.
Before that, they were used in commercial vehicles and trucks since 1985.

You ever driven a 535d bet yours isn't as quick.

I like how the goverment have pushed the fact that removing theses DPFs is a serious threat to our health this that and the next thing. They know the go wrong, they know that they cost a fortune to repair and by policing it are given us no other choice to fork out thousands on repairs. If you think of the amount of diesel cars in the uk with these DPFs that is a nice tasty amount of revenue through tax alone. But what they haven't mentioned is these companies that offer to remove these filters also remap the engines ECU to counteract the fact the filter has been removed therefore improving economy and dare I say it improving the emissions than when they had the filter on.

This is going to a nightmare to enforce. Suppose you bought a second hand diesel which had the DPF removed? So now you have to pick up the bill for someone else? I think people are very judgemental of diesel drivers and think we are polluting tight-wads who do not want to spend money. I love the way a diesel pulls and think that a driver should have the right and autonomy to choose to drive whatever car they want. People who say that DPF's are great and should have been enforced long ago are not thinking straight. How can a DPF be considered 'environmentally friendly' when it forces drivers to take long drives, buying and burning up fuel for no reason, releasing more emissions? Is this some kind of ploy to force people to buy petrol engines? I mean look how the EcoBoost engine was arse-licked by Honest John, even though it had just come out and had no history of reliability yet. A lot of people did not get advised at the time of purchase about the DPF, and have had endless problems with them costing thousands to fix. I hate petrol engines as they always feel a little gutless to me, but seems this interfering government just wants to control every aspect of your life. I went to Sainsbury's yesterday and could not even buy a normal GLS 60w clear light bulb, as they only stock those headache inducing, mercury-filled eco bulbs. Joke.