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Hippo



Member Since: 23 Feb 2014
Location: uk
Posts: 140

United Kingdom 
DPF - how do you know it's ready to cycle

I'm looking at Metropolis's in loire blue. I was wondering if you get a warning on the dash before the DPF thing needs to cycle/regenerate? Like an 80 full indication warning or similar tell you it will happen soon?
Thanks. Hippo's videos - Honorary Tratterer

Post #270344 22nd Jul 2015 8:32 pm
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Past master



Member Since: 30 Jun 2010
Location: Isle of Ely
Posts: 2710

United Kingdom 

Not as far as I know. If it does I've never seen it. I think you only get a warning if the recycle doesn't work and you need to visit dealer. Ex AA Series III LWB Safari - Gone
300TDi Disco (bought new - terrible car) sent back after 18 months
Freelander 1 Estate - leased, given back at end of lease
200TDi Disco (bought from a mate with 100,000 on the clock) - Gone
Disco 2 TD5 - sold and exported to France
FR2 TD4 GS - Gone
FR2 SD4 HSE - Now changed for a DS
New model ex-demo Evoque S 180 in white
Unable to order a new DS, so gave up. Now have a Volvo S90 Recharge.

Post #270345 22nd Jul 2015 8:35 pm
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sid



Member Since: 16 Jul 2015
Location: devon
Posts: 491

England 2009 Freelander 2 TD4 HSE Manual Stornoway Grey
Re: DPF - how do you know it's ready to cycle

Hippo wrote:
I'm looking at Metropolis's in loire blue. I was wondering if you get a warning on the dash before the DPF thing needs to cycle/regenerate? Like an 80 full indication warning or similar tell you it will happen soon?
Thanks.
in 2007 the dpf filter was an optional extra on my hse,thank god the original owner went for privacy glass instead! Very Happy

Post #270376 22nd Jul 2015 10:58 pm
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Hippo



Member Since: 23 Feb 2014
Location: uk
Posts: 140

United Kingdom 

I thought things like dpf's would have sorted out by now. As long as you give it a run to "do it's stuff" then they're ok. Do they need replacing like exhausts? Hippo's videos - Honorary Tratterer

Post #270378 22nd Jul 2015 11:30 pm
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Landiroamer



Member Since: 30 Apr 2015
Location: Devon
Posts: 1185

United Kingdom 2015 Freelander 2 TD4_e SE Manual Orkney Grey

You sometimes get a hot smell and a wisp of smoke out the back as it finishes the regen, unless you notice that you never really know whether its happened or not, anyway if it doesnt do it your car will eventually go into slow mode as its clogged up, great this modern technology. Rolling Eyes

Post #270384 23rd Jul 2015 4:26 am
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simong_uk



Member Since: 31 Jan 2014
Location: Sutton Coldfield
Posts: 146

United Kingdom 2014 Freelander 2 TD4 GS Manual Orkney Grey

mine sits at high idle and doesn't do the eco thing, plus smells like its about to catch fire on the two occasions its kicked in when I've been on a run then got stuck in traffic... 2000 Xei 1.8 gone
2004 HSE Td4 Auto, MT's, sump guard, sliderz - gone
2014 GS Man - AT's, Mantec Sump guard and tank guard, split charger in boot, towbar, work in progress...

Post #270397 23rd Jul 2015 7:38 am
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Past master



Member Since: 30 Jun 2010
Location: Isle of Ely
Posts: 2710

United Kingdom 

The handbook does warn about parking in long grass and causing a fire! Lots of problems with early ones (mainly export) but since introduced here they seem pretty reliable. Think of it as your small contribution to the NHS - thousands of people every year die early in London alone because of diesel fumes. The DPF doesn't do everything, but it cuts down on the particulates which are part of the cause, and has earned us a breather before diesels are banned in cities (they almost certainly will be). Ex AA Series III LWB Safari - Gone
300TDi Disco (bought new - terrible car) sent back after 18 months
Freelander 1 Estate - leased, given back at end of lease
200TDi Disco (bought from a mate with 100,000 on the clock) - Gone
Disco 2 TD5 - sold and exported to France
FR2 TD4 GS - Gone
FR2 SD4 HSE - Now changed for a DS
New model ex-demo Evoque S 180 in white
Unable to order a new DS, so gave up. Now have a Volvo S90 Recharge.

Post #270488 23rd Jul 2015 4:26 pm
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SaabDriver



Member Since: 08 Jun 2015
Location: Yorkshire
Posts: 88

England 2014 Freelander 2 TD4 GS Auto Loire Blue

I don't know what method the Freelander uses to regen the DPF but on my Saab it injects extra fuel on the exhaust stroke to raise the temp to what is needed to burn off what it has trapped and the only way to tell it has started is to have the display on distance to empty, it drops about 50% while it is regening. Mine, Saab convertible
Hers, MY08 GS auto

Post #270534 23rd Jul 2015 10:57 pm
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Hippo



Member Since: 23 Feb 2014
Location: uk
Posts: 140

United Kingdom 
Re: DPF - how do you know it's ready to cycle

Thanks for your help.

I was reading the Haynes manual and found a brief section about the dpf. I then remembered I have a copy of the larger repair manual. This covers it in more detail. The last 2 paragraphs say the dash will give 1 of 2 warnings if there's a problem. I have to admit I didn't realised the dpf's were so technical.


repair manual wrote:
For models fitted with an exhaust system diesel particulate filter, the high-pressure fuelling system also provides post combustion injection of fuel into the combustion chambers. When regeneration of the diesel particulate filter is requested, the ECM allows the fueling system to deliver fuel after the combustion stroke and into the commencement of the exhaust stroke. This post combustion injection process causes fuel to be burnt in the exhaust system and creates the high exhaust gas temperatures that are required to regenerate the diesel particulate filter.
...

The DPF is located in the exhaust system, downstream of the catalytic converter. A major feature of the DPF is its ability for regeneration. Regeneration is the burning of particulates trapped by the filter to prevent obstruction to the free flow of exhaust gasses. The regeneration process takes place at calculated intervals and is not noticeable by the driver of the vehicle.

Regeneration is most important, since an overfilled filter can damage the engine through excessive exhaust back pressure and can itself be damaged or destroyed. The material trapped in the filter is in the most part carbon particles with some absorbed hydrocarbons.

The DPF uses a filter technology based on a filter with a catalytic coating. The DPF is made from silicon carbide housed in a steel container and has excellent thermal shock resistance and thermal conductivity properties. The DPF is designed for the engine's operating requirements to maintain the optimum back pressure requirements.

The porous surface of the filter consists of thousands of small parallel channels positioned in the longitudinal direction of the exhaust system. Adjacent channels in the filter are alternately plugged at the end. This design forces the exhaust gasses to flow through the porous filter walls, which act as the filter medium. Particulate matter which are too big to pass through the porous surface are collected and stored in the channels.

The collected particulate matter, if not removed, can create an obstruction to exhaust gas flow. The particles are removed by a regeneration process which incinerates the particles.

The regeneration process uses NO2 to remove the particles from the DPF. The NO2 is generated by the catalytic converter upstream of the DPF. The catalytic converter produces temperatures in excess of 250°C (482°F) at which point the regeneration process is started.

DPF regeneration is controlled by the temperature of the exhaust gasses and the DPF. The DPF includes a wash coat to the filter surface which comprises platinum and other active components and is similar to the catalytic converter. At certain exhaust gas and DPF temperatures the wash coat promotes combustion and incineration of the particles in addition to oxidizing carbon monoxide and hydrocarbon emissions.

The exhaust gas and DPF temperatures are controlled by the DPF software located in the ECM. The DPF software monitors the load status of the DPF based on driving style, distance traveled and signals from the differential pressure sensor and temperature sensors. When the particulate loading of the DPF reaches predetermined levels, the DPF is actively regenerated by adjusting, in conjunction with the ECM, various engine control functions such as:

  • fuel injection
  • intake air throttle
  • exhaust gas recirculation
  • turbocharger boost pressure control.


The regeneration process is possible because of the flexibility of the common-rail fuel injection engine which provides precise control of fuel flow, fuel pressure and injection timing which are essential requirements to promote the efficient regeneration process.

Two processes are used to regenerate the DPF; passive and active.

Passive Regeneration
Passive regeneration requires no special engine management intervention and occurs during normal engine operation. The passive regeneration involves a slow conversion of the particulate matter deposited in the DPF into carbon dioxide. This process is active when the DPF temperature reaches 250°C (482°F) and is a continuous process when the vehicle is being driven at higher engine loads and speeds.

During passive regeneration, only a portion of the particulate matter is converted into carbon dioxide. This is due to the chemical reaction process which is only effective within the normal operating temperature range of 250°C to 500°C (482°F to 932°F).

Above this temperature range the conversion efficiency of the particulates into carbon dioxide increases as the DPF temperature is raised. These temperatures can only be achieved using the active regeneration process.

Active Regeneration
Active regeneration starts when the particulate loading of the DPF reaches a threshold as monitored or determined by the DPF control software. The threshold calculation is based on driving style, distance travelled and back pressure signals from the differential pressure sensor.

Active regeneration generally occurs every 450 miles (725 km) although this is dependant on how the vehicle is driven. For example, if the vehicle is driven at low loads in urban traffic regularly, active regeneration will occur more often. This is due to the rapid build-up of particulates in the DPF than if the vehicle is driven at high speeds when passive regeneration will have occurred.

The DPF software incorporates a mileage trigger which is used as back-up for active regeneration. If active regeneration has not been initiated by a back pressure signal from the differential pressure sensor, regeneration is requested based on distance traveled.

Active regeneration of the DPF is commenced when the temperature of the DPF is increased to the combustion temperature of the particles. The DPF temperature is raised by increasing the exhaust gas temperature. This is achieved by introducing post-injection of fuel after the pilot and main fuel injections have occurred.

This is determined by the DPF software monitoring the signals from the two DPF temperature sensors to establish the temperature of the DPF. Depending on the DPF temperature, the DPF software requests the ECM to perform either one or two post-injections of fuel:

  • The first post-injection of fuel retards combustion inside the cylinder which increases the temperature of the exhaust gas.
  • The second post-injection of fuel is injected late in the power stroke cycle. The fuel partly combusts in the cylinder, but some unburnt fuel also passes into the exhaust where it creates an exothermic event within the catalytic converter, further increasing the temperature of the DPF.


The active regeneration process takes approximately 20 minutes to complete. The first phase increases the DPF temperature to 500°C (932°F). The second phase further increases the DPF temperature to 600°C (1112°F) which is the optimum temperature for particle combustion. This temperature is then maintained for 15-20 minutes to ensure complete incineration of the particles within the DPF. The incineration process converts the carbon particles to carbon dioxide and water.

The active regeneration temperature of the DPF is closely monitored by the DPF software to maintain a target temperature of 600°C (1112°F) at the DPF inlet. The temperature control ensures that the temperatures do not exceed the operational limits of the turbocharger and the catalytic converter. The turbocharger inlet temperature must not exceed 830°C (1526°F) and the catalytic converter brick temperature must not exceed 800°C (1472°F) and the exit temperature must remain below 750°C (1382°F).

During the active regeneration process the following ECM controlled events occur:

  • The turbocharger is maintained in the fully open position. This minimizes heat transmission from the exhaust gas to the turbocharger and reduces the rate of exhaust gas flow allowing optimum heating of the DPF. If the driver demands an increase in engine torque, the turbocharger will respond by closing the vanes as necessary.
  • The throttle is closed as this assists in increasing the exhaust gas temperature and reduces the rate of exhaust
    gas flow which has the effect of reducing the time for the DPF to reach the optimum temperature.
  • The Exhaust Gas Recirculation (EGR) valve is closed. The use of EGR decreases the exhaust gas temperature and therefore prevents the optimum DPF temperature being achieved.


If, due to vehicle usage and/or driving style, the active regeneration process cannot take place or is unable to regenerate the DPF, the dealer can force regenerate the DPF. This is achieved by either driving the vehicle until the engine is at its normal operating temperature and then driving for a further 20 minutes at speeds of not less than 30 mph (48 km/h) or by connecting a Land Rover approved diagnostic system to the vehicle which will guide the technician through a regeneration procedure to clean the DPF.

For drivers who make regular short journeys at low speeds, it may not be possible to efficiently regenerate the DPF. In this case, the DPF software will detect a blockage of the DPF from signals from the differential pressure sensor and will alert the driver as follows.

The driver will be alerted to this condition by a message 'DPF FULL' accompanied by a handbook symbol. As detailed in the Owners Handbook, the driver should drive the vehicle until the engine is at its normal operating temperature and then drive for a further 20 minutes at speeds of not less than 30 mph (48 km/h). Successful regeneration of the DPF is indicated to the driver by the 'DPF FULL' message no longer being displayed. If the DPF software detects that the DPF is still blocked, the message will change to 'DPF FULL VISIT DEALER', the driver should take the vehicle to an authorized dealer to have the DPF force regenerated.
 Hippo's videos - Honorary Tratterer

Post #271495 2nd Aug 2015 12:01 pm
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Landiroamer



Member Since: 30 Apr 2015
Location: Devon
Posts: 1185

United Kingdom 2015 Freelander 2 TD4_e SE Manual Orkney Grey

If youre worried about the DPF regenerating, or lack of it because of short journeys I see you can get an additive to put into the fuel to assist it?? now whether that works I dont know, some say they use it and they have never had any trouble doing short trips??

Post #271506 2nd Aug 2015 2:43 pm
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Hippo



Member Since: 23 Feb 2014
Location: uk
Posts: 140

United Kingdom 

Most of my trips are short. Around 3 to 5 miles. I don't mind taking it for a run or doing a longer trips for the regen process to complete if that's all I need to do. Just making sure I know what to expect. Thanks. Hippo's videos - Honorary Tratterer

Post #271509 2nd Aug 2015 2:52 pm
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ad210358



Member Since: 12 Oct 2008
Location: Here and There
Posts: 7464

England 

Don't worry about the DPF, never was a problem on mine, most of the journeys were two to three miles in town, never added any Snake Oil, never had a DPF problem, same with the Disco we now have, same journeys no Snake Oil added, never been a problem.

Have a search on here for members with DPF problems,, you can just about count the problems on the fingers of a fist, the couple that had problems were within a few days of leaving the forecourt. Your worrying about a problem that doesn't exist. p****d off with a Digital Keyboard Warrior

Post #271553 2nd Aug 2015 8:56 pm
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Atrix



Member Since: 26 Jan 2010
Location: RIGA
Posts: 83

Latvia 2009 Freelander 2 TD4 S Manual Lago Grey

Apart from the burn smell you can have a vague hint concerning the start of regeneration process by increased instant fuel consumption figures provided you have it reset recently. Otherwise you won't notice the diffrence compared to avarage consumption.

Post #272431 11th Aug 2015 1:09 pm
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