DPF removal check to be part of UK MOT test from February 2014

[Brimma]

I love speculation

It's almost like when there's a plane crash, or a ferry disaster, and all the news programmes are filled with 'experts' voicing their opinion on what MIGHT have happened, before they even know the facts

[fordfan]

How would you go about getting a list of cars with DPF's fitted from the factory? 

Shouldn't be difficult as the emissions standard will be on the registration document.  All it'll take is for a bit of an update on the MOT computer to notify the tester what emissions standard the car was built to.  Like spark ignition engines and catalysts it'll be impossible to get a diesel car up to Euro 5, without it having a DPF.

 

The current MOT computerised system will be getting replaced by a completely new one by 2015.

[silver1011]

I was just curious, an early vRS owner (a PD170, as these are proven to suffer premature DPF failures) removes the DPF and fits a straight through pipe in it's place.

 

Imagine for the sake of the visual inspection that it was impossible to tell if a DPF was originally fitted.

 

What information would the MOT tester need to refer to to be able to determine for sure that the car he is testing (or attempting to fail) ever had a DPF fitted?

 

You mention the emissions standard but diesels aren't tested for emissions, simply a soot test, which is passable by cars not even fitted with DPF's.

 

What evidence is needed and what evidence would need to be provided to fail the MOT?

 

 Are there are Euro 4 engines out there without DPF's?

Edited 7 December, 2013 by silver1011

[Metblackrat]

From the legal side of things, it's not illegal to remove the DPF. It is illegal to drive that vehicle on a road, sell it or, as the owner or keeper, permit someone else to drive it.

Regulation 61 Road Vehicles (Construction and Use) Regulations 1986 states this.

The companies removing them should advise this but don't legally have to. Morally, maybe they should. It's the same with tinting front windows. It's not an offence to fit them or sell them, it's only an offence when you use it on the road.

[silver1011]

I'm not yet 100% convinced. As I see it...

 

Removing the DPF isn't illegal.

 

Driving a car with its DPF removed on the road isn't illegal.

 

However driving a car on the road that does not meet the 'air pollutant emissions standards' is illegal.

 

It is likely that removing the DPF will prevent the car from meeting those emissions standards, however it may be possible that it might continue to meet the standards. Who knows for sure?

 

As diesels don't have their emissions tested as part of the MOT it would also be difficult to prove.

Edited 7 December, 2013 by silver1011

[nick74]

Are there are Euro 4 engines out there without DPF's?

Yes loads, including every 1.9pd and many 2.0pd mk2 Octavia's. Most of the Octavia pd's scraped through Euro 4 without a DPF. It was only on the vRS and Scout versions that the figures exceeded, or at least got a bit too close to the Euro 4 limits for comfort, and DPFs were fitted to bring the particulates down on those models.

[JungleJames]

I know ive kept saying removing the DPF is and always has been illegal. However to clarify, i was thinking more along the lines of silver1011. Its illegal to not comply with the emissions regs for that particular car. However, pretty much all cars (Euro V) fitted with a DPF will need that DPF to comply. Thats why i said it was illegal outright. You'll be extremely lucky to comply without a DPF.

Saying that, JCB i think reckon they have an engine that doesnt require a DPF to comply. There are alternatives. Not sure any of these would be suitable for a cars engine though.

[mattvrestate]

This thread has got a little rediculous. Scaremongering from people without basic knowledge of MOT testing and getting confused by mixing legalitys with MOTs.

As an MOT tester the number 1 rule is

If you cant see it.

You CANT fail it!

A vehicle with a DPF still fitted but the internals have been removed will NOT fail in feb for not having a DPF fiited. It will NOT be a testers responsibily to investigate whether there is soot around the exhaust OR whether there are welds on the DPF and it will NOT be a requirement to tap the DPF to see what it sounds like!

The current fail for the Presents if a Catalystic Converter on a petrol is a visual check ONLY. If the Cat is there then it CANNOT fail for "not being present" regardless as to whether the internals are there or its a sports cat etc..

What you may find is that some of the earlier PD vehicles MAY produce enough smoke to fail the smoke test after having the DPF removed due to the harsher smoke limits for post 2008 cars. The CR engines dont produce alot of soot/ smoke without the DPF so i doubt they will fail.

And as for "Legalitys" and the Briskoda favourite "Insurance" they both have jack all to do with the feb 2014 DPF not present MOT fail

/thread

[Anzio]

I'm fed up reading some of the silly remarks about DPF's. In simple terms the reason the DPF is there is to stop soot particles from being blasted into the atmosphere,thus causing a health hazard. It's all part of the worldwide policy to clean up the air we all need to live.

[silver1011]

I'm fed up reading some of the silly remarks about DPF's. In simple terms the reason the DPF is there is to stop soot particles from being blasted into the atmosphere,thus causing a health hazard. It's all part of the worldwide policy to clean up the air we all need to live.

 

Unfortunately the DPF fitted to the VAG PD170 engine in a lot of cases doesn't work very well at all.

 

It was great for reducing pollution though mainly because mine spent most of the time either in the dealers or in limp-home mode.

 

Silly remarks about DPF's or in this particular case a silly design of DPF?

[trundlenut]

I'm fed up reading some of the silly remarks about DPF's. In simple terms the reason the DPF is there is to stop soot particles from being blasted into the atmosphere,thus causing a health hazard. It's all part of the worldwide policy to clean up the air we all need to live.

 

The potential issue is that a DPF stops a certain size range of particles.  Finer particles pass straight through and the regeneration also produces finer particles, as well as gases.  The question is whether these finer particles pose more or less of a risk than the larger particles.  Due to their size it is difficult to collect and measure them and assess the risks they pose to human health.

[Huskoda]

DPFs merely exchange one form of pollution for another. They do not magically make everything better. The soot looks bad and I'm sure is harmful, but they put out other, finer, particulate pollution, extra CO2 from burning off the soot and increase fuel consumption, in some cases heavily if you need to do frequent regenerations.

[seboni121]

If the regeneration is unsuccessful the extra fuel injected will not burn and will drain into the sump. Oil quality will deteriorate as a result of this and the level will rise. It is important that you check that the oil level does not increase above the maximum level on the dipstick as diesel engines can run on excess engine oil – often to the point of destruction.

Insurance

You must notify your insurer if the vehicle is modified but such a modification could in turn invalidate any insurance cover because it makes the vehicle illegal for road use.

Edited 13 December, 2013 by seboni121

[Huskoda]

If the regeneration is unsuccessful the extra fuel injected will not burn and will drain into the sump. Oil quality will deteriorate as a result of this and the level will rise. It is important that you check that the oil level does not increase above the maximum level on the dipstick as diesel engines can run on excess engine oil – often to the point of destruction.

 

I thought this was only a big issue on Mazda 2.2l diesel engines?

[seboni121]

? But if fuel is added to regenerate and is unsuccessful the fuel has to go somewhere ?

[seboni121]

The ash residue which remains after successful regeneration cannot be removed and will eventually fill the filter. DPFs are designed to last about 75,000 miles, but many, operating correctly, are achieving more than this.

[seboni121]

You can remove and jet wash the ****e out and replace it

[Huskoda]

I thought the excess fuel just goes out the exhaust and the diesel into oil issue was due to the design of Mazda's DPF. My DPF has 110,000 miles on it and when last checked only showed about 5% full. I just don't let it drop below 2000 RPM. So much for being economical...

[seboni121]

Just seen this article

Your car is fitted with a DPF (Diesel Particulate Filter) and you have heard a lot of stories about expensive repair bills, regenerations and additives... So you look on the internet for how you keep your DPF healthy and how 'DPF Regeneration' is performed!! Good news.... Its not all doom and gloom when it comes to your DPF

Firstly, what is DPF regeneration?

Well to best answer that, let's take a look at what the DPF actually does.... The DPF is a particulate filter, fitted to the exhaust system on diesel cars, it is designed to trap harmful particulates in the exhaust gases. Once the amount of trapped particles otherwise known as soot loading becomes too great engine ECU senses this and carries out the DPF regeneration process.

Now we know that, we can better understand DPF regeneration.... A question I often see is what is the point in the DPF trapping the particles if it's only going to chuck them out the exhaust during regeneration? Answer is, it does but it doesn't. What happens is the during regeneration the exhaust gets to a hot enough temperature, ideally around 600 degrees celsius, that through some clever chemistry, the harmful particles or hydrocarbons react with the catalyst inside and become less harmful particles. I'm sure we have all heard of our good friends H2O and CO2 otherwise know as water and carbon dioxide.

So what can be done to keep your DPF clean and happy?

So it turns out, short trips and urban driving don't do your DPF and favours, only assisting in filling the DPF faster. This is because when an engine is cold it doesn't burn fuel as cleanly as when the engine is hot, another side effect is that the exhaust doesn't get hot enough for a long enough period of time to carry out the DPF regeneration. So how can you combat this. Well depending on how many short trips you do over a week or fortnight, the best thing you can do is get your car on the dual carriageway and then drive according to the following points!!

Ensure engine is at operating temperature.

Drive in fourth or fifth gear.

Drive above 50 mph.

Keep engine speed between 2000 and 3000 rpm.

Keep going for at least 20 miles.

As long as the above is followed, if vehicle senses that a DPF regeneration needs to be carried out it will do so automatically without the need for any diagnostic tools!!!

Another thing you can do, is to use either the more expensive diesels such as BP Ultimate or other premium fuels, or a good diesel additive. This is because better diesel has a higher cetane rating, the higher the cetane rating the better the combustion quality or cleaner burn, in turn not loading the DPF as much, resulting in less frequent DPF regeneration processes. A good side effect of using better diesel is better EGR (Exhaust Gas Recirculation) health and it helps to keep the engine internals cleaner.

Another step to take is to ensure servicing work is carried out at the correct time and to the correct standard. See here. What is a car service.

This is because some vehicles have an additive tank which needs filling with the correct additive as part of some service schedules.

So what actually goes wrong with your DPF. Well some common issues are...

The pressure differential sensor can fail.

Too many DPF regenerations have been carried out. (They have a limited lifespan).

The DPF has become overloaded and automatic regeneration is not possible. In this case you need to force the regeneration process using suitable diagnostic equipment.

The DPF can break apart internally.

The temperature sensor can fail.

The additive tank can run empty. (If fitted).

There are other failures but these are the most common.

For some people the cost of DPF failure is too great, and in an attempt to prevent further failure they seek to remove the DPF entirely more on that here. DPF Removal.

[trundlenut]

The ash residue which remains after successful regeneration cannot be removed and will eventually fill the filter. DPFs are designed to last about 75,000 miles, but many, operating correctly, are achieving more than this.

Mines done nearly 80k and the ash content is less than 30g.

Sent from my Nexus 4 using Tapatalk

[seboni121]

I thought the excess fuel just goes out the exhaust and the diesel into oil issue was due to the design of Mazda's DPF. My DPF has 110,000 miles on it and when last checked only showed about 5% full. I just don't let it drop below 2000 RPM. So much for being economical...

Yes husky you could well be right in regards the Mazda , I've had several cars now with dpf and never any issues, however is you drive it like an old git it will block ( sounds like most on here to be honest) I always use she'll vpower and bg244 , the other option is to remove and keep it for mot (replace)

[seboni121]

Mines done nearly 80k and the ash content is less than 30g.

Sent from my Nexus 4 using Tapatalk

There you go no need to remove it ? How much performance would you gain by removing ? Very minimal I guess ,also fuel economy I get 70mpg what real difference would removing do ?

[Huskoda]

I get 40 MPG. Without a DPF I could drive it like a granny

 

You don't have to drive it like you stole it to keep above 2000 RPM either. 2000 RPM in 6th in mine is 63MPH (GPS). Below that, I change up at 2500 and next gear lands at 2000.

 

The bonus is also the engine never labours and so the DMF should be fine (which it is).

[seboni121]

I get 40 MPG. Without a DPF I could drive it like a granny

 

You don't have to drive it like you stole it to keep above 2000 RPM either. 2000 RPM in 6th in mine is 63MPH (GPS). Below that, I change up at 2500 and next gear lands at 2000.

 

The bonus is also the engine never labours and so the DMF should be fine (which it is).

Have you ever used the additives ?

[trundlenut]

There you go no need to remove it ? How much performance would you gain by removing ? Very minimal I guess ,also fuel economy I get 70mpg what real difference would removing do ?

I don't have any plans to remove it, but then I have an ideal commute for a dpf - a 15 mile section of dual carriageway twice a day that I do an indicated 65, which equates to 2000rpm.

Sent from my Nexus 4 using Tapatalk