Not Stag related, emmission testing , mixtures etc

[jakesmig]

My oil burner passed its first MOT today, with one advisory relating to a cracked door mirror cowl, and on being asked about the emissions the tester said it was one of the cleaner ones he's done recently. Begs the question about what use the DPF systems on modern diesels are, I had the one in mine removed and the ECU retuned when it developed a 'fault' at 12500 miles. Since its removal i've gained 10 - 15% better fuel economy under normal conditions, better if I try, so on that basis I must be emitting less crud per mile which must benefit the environment. It would make me think twice before I forked out for a replacement system.

Which brings me onto my next musing.

Whilst sorting the Stags B post the other night my mind wandered back 2/3 decades to the times I drove carburettored cars and recalled that a rough way to judge a cars health was the colour of the residue in the exhaust tail pipe. If it was tan coloured it was running well, black and it was running rich. I also recall getting a roasting from the old man if it was white because that meant you'd been belting it.

I don't recall seeing any modern, petrol engined, car which doesn't have a black sooty residue in the tail pipe. Perhaps the modern ECU doesn't allow the mixture to lean down enough to allow a clean exhaust pipe.

John

[staggering]

John,
I maybe wrong (and open to better advise) but I think we kissed goodbye to the tan / off grey exhaust pipe colours when we all had to go "unleaded" - can't remember where I got that from as it was many moons ago

Cheers
Ian

[milothedog]

My oil burner passed its first MOT today, with one advisory relating to a cracked door mirror cowl, and on being asked about the emissions the tester said it was one of the cleaner ones he's done recently. Begs the question about what use the DPF systems on modern diesels are, I had the one in mine removed and the ECU retuned when it developed a 'fault' at 12500 miles. Since its removal i've gained 10 - 15% better fuel economy under normal conditions, better if I try, so on that basis I must be emitting less crud per mile which must benefit the environment. It would make me think twice before I forked out for a replacement system.

Which brings me onto my next musing.

Whilst sorting the Stags B post the other night my mind wandered back 2/3 decades to the times I drove carburettored cars and recalled that a rough way to judge a cars health was the colour of the residue in the exhaust tail pipe. If it was tan coloured it was running well, black and it was running rich. I also recall getting a roasting from the old man if it was white because that meant you'd been belting it.

I don't recall seeing any modern, petrol engined, car which doesn't have a black sooty residue in the tail pipe. Perhaps the modern ECU doesn't allow the mixture to lean down enough to allow a clean exhaust pipe.

John

Not sure if you know John, and as far as I'm aware unless it has changed in the last 18 months, a Diesel emission test is purely based on smoke density. (no gas analysis) The equipment used is as simple as how much of a transmitted light beam is received buy the senor on the other side in the tester that is placed in the exhaust gas stream. an easy test really for a mdern engine in good nick.

Ian.

[Kevin Garrod]

I think we kissed goodbye to the tan / off grey exhaust pipe

Cheers
Ian

Let it cool down first!

[KOY 23]

John,
I maybe wrong (and open to better advise) but I think we kissed goodbye to the tan / off grey exhaust pipe colours when we all had to go "unleaded" - can't remember where I got that from as it was many moons ago

Cheers
Ian

I think you are right.

[KOY 23]

Let it cool down first!

Been there, done that Kevin?

[milothedog]

Been there, done that Kevin?

Do you know about the brake test one, get the tyres wet before you put it in the rollers

[jleyton]

John,

I've considered DPF removal but then this came out about a month ago

https://www.gov.uk/government/news/new-rules-for-mot-to-test-for-diesel-particulate-filter

Cheers

Julian

Ps This is from one of the related government documents:

A vehicle might still pass the MoT visible smoke emissions test, which is primarily intended to identify vehicles that are in a very poor state of repair, whilst emitting illegal and harmful levels of fine exhaust particulate.

It is an offence under the Road vehicles (Construction and Use) Regulations (Regulation 61a(3))^[1] to use a vehicle which has been modified in such a way that it no longer complies with the air pollutant emissions standards it was designed to meet. Removal of a DPF will almost invariably contravene these requirements, making the vehicle illegal for road use. The potential penalties for failing to comply with Regulation 61a are fines of up to £1,000 for a car or £2,500 for a light goods vehicle.

---

^[1] http://www.legislation.gov.uk/uksi/1.../contents/made




Press release
New rules for MOT to test for diesel particulate filter





Organisation:Department for Transport
Page history:Updated 4 December 2013, see all updates4 December 2013 3:31pmFirst published.4 December 2013 3:31pm
Policy:Reducing greenhouse gases and other emissions from transportTopics:Climate change and TransportMinister:Robert Goodwill MP

Diesel particulate filter check now required as part of MOT test.






Tests for diesel cars and lorries are to be tightened up to ensure vehicles have a critical exhaust filter if one had originally been fitted as standard, Roads Minister Robert Goodwill has announced.
Garages and testing stations will be required check for a diesel particulate filter (DPF) in the inspection of the exhaust system as part of the MOT test (or annual test for heavy vehicles) from February 2014.
The vehicle will automatically fail the MOT test if the filter had been fitted as standard but is found to be no longer present.
The filter works by trapping solid particulate matter from exhaust gases. This type of filter has been in use for more than 20 years and helps meet European emission standards, improving air quality and health standards.
Some firms offer services to remove the filter, claiming it will improve the economy. But it is an offence to drive a vehicle that has been modified this way, as it will no longer meet the emissions standards the car achieved when it was approved for sale in the UK.
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. It has become apparent the government had to intervene to clarify the position on particulate filter removal given the unacceptable negative impact on air quality.
This change to the MOT tests makes it clear – if you have this filter removed from your car it will fail the test.

The filters need to be ‘regenerated’ regularly through burning the soot to gas at a very high temperature, leaving behind a residue. If not carried out properly, regeneration can lead to a build up of soot, which can affect performance. This has led to some diesel vehicle owners opting to remove the filter, which makes their car illegal for road use.

[tractorjames]

Ill be honest im not too up on car type diesel emissions but the americam tier type system that agricultural machines use is mad. without a doubt a 'modern' diesel is less economical on fuel that a like for like 'old' engine, as already stated they are only bothered about the crud that comes out. Our engines are injecting an extra spurt of fuel at the end of the power stroke to get a cleaner exhaust. Although less soot, more fuel used .

I cant remember the name but bosch do a really interesting book on the modern common rail fuel system, will try and have a look what its called.

James

[Staghound]

All seems a bit pointless when China and any volcano you choose to mention produces way more crap in the atmosphere than UK cars ever will...

Andrew.

[jakesmig]

Not sure if you know John, and as far as I'm aware unless it has changed in the last 18 months, a Diesel emission test is purely based on smoke density. (no gas analysis) The equipment used is as simple as how much of a transmitted light beam is received buy the senor on the other side in the tester that is placed in the exhaust gas stream. an easy test really for a mdern engine in good nick.

Ian.

"John,

I've considered DPF removal but then this came out about a month ago

https://www.gov.uk/government/news/n...iculate-filter"

Ian, yes, I knew about that part of the test and the equipment involved. As far as I understand it, there are 2 basic types of DPF valve systems, one which incects an 'Ad blu' solution to eradicate the soot collected and the other which injects unburnt diesel into the valve which burns off the soot, emitting additional CO2 into the bargain. Mine was the latter and I quess my fuel savings come from not injecting the fuel into the valve.

Julian, I still have the body of the DPF valve, the internals have been removed so the system looks as per spec.

I don't use the franchised dealer for servicing, A because he is too expensive, and B, the garage I use have mechanics I know trust. 500 miles after the first service the DPF light came on and stayed on, which meant a visit to the franchised garage. They smirked whilst saying I had to get the service from a dealer because part of the service was cancelling the DPF log which only a dealer could do. He then advised that their charge would be £98 for cancelling the fault, and failure to do so would bugger the system which would cost £1500 to replace.
I politely told him where to go and the next day the DPF was removed.

John.

[jakesmig]

John,
I maybe wrong (and open to better advise) but I think we kissed goodbye to the tan / off grey exhaust pipe colours when we all had to go "unleaded" - can't remember where I got that from as it was many moons ago

Cheers
Ian

That would explain it, thanks for that.

John

[jleyton]

As far as I understand it, there are 2 basic types of DPF valve systems, one which incects an 'Ad blu' solution to eradicate the soot collected and the other which injects unburnt diesel into the valve which burns off the soot,

John.

Hi John,

It is more complicated than that !

I worked in the Press office at Citroen, who were the first manufacturers to introduce a car in the UK with a particulate filter - shortly before Mercedes. It was thetefore my job to explain this new technology to the UK media .


Personally I have mixed views over DPFs - they do use a little more fuel, however the exhaust emissions are dramatically cleaner. To prove this to journalists, after they'd been on a test drive in the new DPF equipped Xantia, I took them around to the back of the car and wiped my finger around the INSIDE of the exhaust. It was completely clean and then, to prove the point, I licked my finger It really was that clean.

However, as it looked likely that DPFs were going to become mandatory, other manufacturers introduced systems that were cheaper to produce, but which brought with them certain problems.

Cheers

Julian

Ps Unless things have changed since I retired (quite possible) all systems use a complex filter that traps particulate matter which is then burnt off at very high temperature when the system senses that the filter is becoming full (by pressure differential at entrance and exit of the filter) This is called the ‘regeneration’ mode and the high temperature required for this ‘burn off’ is achieved partly as a result of the heat produced by the standard catalytic convertor but then also by the system injecting extra fuel that, effectively, sends a flame front down the exhaust to incinerate the trapped residue.

However, the system used by Citroen and Peugeot utilises an extra step that improves the efficiency and reliability of the system.

I don’t recollect the exact temperatures involved but IIRC it is something like 500 degrees Celsius. The catalyst takes the temperature up to 400 and the additional injection creates the extra heat. Obviously, if the car is being driven hard then the operating temperatures will be higher whilst, alternatively, if it is being driven sedately, it will be cooler. This is why it is often recommended to give the car a blast.

Having said all of this, the system used on Citroen and Peugeot vehicles employs an extra step to improve the system. Whenever the tank is refuelled, a small amount of additive (Eolys), which is stored in a separate container, is automatically injected into the fuel. This additive reduces, by about 100 degrees, the burn off temperature for particulates produced by this fuel. Consequently, the regeneration is much more effective.

[Jeff]

Hi John,

It is more complicated than that !

I worked in the Press office at Citroen, who were the first manufacturers to introduce a car in the UK with a particulate filter - shortly before Mercedes. It was thetefore my job to explain this new technology to the UK media .


Personally I have mixed views over DPFs - they do use a little more fuel, however the exhaust emissions are dramatically cleaner. To prove this to journalists, after they'd been on a test drive in the new DPF equipped Xantia, I took them around to the back of the car and wiped my finger around the INSIDE of the exhaust. It was completely clean and then, to prove the point, I licked my finger It really was that clean.

However, as it looked likely that DPFs were going to become mandatory, other manufacturers introduced systems that were cheaper to produce, but which brought with them certain problems.

Cheers

Julian

Ps Unless things have changed since I retired (quite possible) all systems use a complex filter that traps particulate matter which is then burnt off at very high temperature when the system senses that the filter is becoming full (by pressure differential at entrance and exit of the filter) This is called the ‘regeneration’ mode and the high temperature required for this ‘burn off’ is achieved partly as a result of the heat produced by the standard catalytic convertor but then also by the system injecting extra fuel that, effectively, sends a flame front down the exhaust to incinerate the trapped residue.

However, the system used by Citroen and Peugeot utilises an extra step that improves the efficiency and reliability of the system.

I don’t recollect the exact temperatures involved but IIRC it is something like 500 degrees Celsius. The catalyst takes the temperature up to 400 and the additional injection creates the extra heat. Obviously, if the car is being driven hard then the operating temperatures will be higher whilst, alternatively, if it is being driven sedately, it will be cooler. This is why it is often recommended to give the car a blast.

Having said all of this, the system used on Citroen and Peugeot vehicles employs an extra step to improve the system. Whenever the tank is refuelled, a small amount of additive (Eolys), which is stored in a separate container, is automatically injected into the fuel. This additive reduces, by about 100 degrees, the burn off temperature for particulates produced by this fuel. Consequently, the regeneration is much more effective.

Blimey Julian, you really are a petrol head! or is it diesel head?

Whilst on the subject of DERV, is there a problem when the yellow glow plug light stays on for a few seconds after the engine has started?

[DJT]

Not sure how it works (and I can't be bothered to Google it in case I get an inaccurate answer ) but I've had an Audi A3 1.9TDIe with a DPF for the past 4.1/2 years (25000 miles). If we don't get out of town for a while an alarm light (which looks like an exhaust catalyst) comes up on the dashboard. A quick trip up the M5 to visit my daughter soon clears it. In fact it clears within a few miles at motorway speeds and stays clear for another month or so of town driving.

The insides of the tailpipes are still clean if you want to do your taste test Julian......