Jump to content
Do Not Sell My Personal Information


Focus Titanium Tdci 2012 - Engine Fan Running


Leysland
 Share

Recommended Posts

Ford Titamium TDCI 2012 1560CC. I've noticed on 3 journeys that upon arrival the engine fan is running and smells hot but the temperature on the dashboard is reading normal. All have been fairly short journeys of up to 1/2 hr in sunny but not particularily hot weather. The fan ran for several minutes before switching off. Water level is OK. On the latest journey the car had been sitting in the sun and it was hot in the car. Before setting out the outside temperature on the dashboard showed 27C although the temperature was clearly not 27C. Despite running at about 70mph on the way home for 1/2hr this 27C didn't come down as you would expect and as climate control was set at 19C it continued to pump cold air into the car. Upon arrival at home I could hear the engine fan was on and ran for several minutes after switching off the engine. As before nothing was untoward on next journey. Is this a sensor issue?

Link to comment
Share on other sites


Hi and welcome to FOC.

Sounds like it could be trying to clean its DPF. Although you will not have the additive type, there are sensors in the exhaust to detect when the DPF is starting to clog up. I would try giving it a blast out. Best way is to spend about 20mins on a dual carriageway or motorway in 3rd. Basically try and keeps the revs around 3k.

During a DPF regen, the car is trying to burn off its soot desposits by deliberatly overheating itself to raise the exhaust temperature. Short journeys cause more soot to build up from the cold engine and the car is not able to complete its cleaning routines.

Link to comment
Share on other sites

Hi and welcome to FOC.

Sounds like it could be trying to clean its DPF. Although you will not have the additive type, there are sensors in the exhaust to detect when the DPF is starting to clog up. I would try giving it a blast out. Best way is to spend about 20mins on a dual carriageway or motorway in 3rd. Basically try and keeps the revs around 3k.

What utter rubbish. there is NO need to keep it in 3rd at 70 to burn the soot out of the DPF. it may have been the case for older diesels without a DPF to clear the soot build up out but not on a diesel engine with a DPF. drive the car normally in 5th/6th at 70 for 25 miles at a constant throttle or better still set the cruise to 70 if fitted keeping the speed above 40.

the engine will over fuel to get the exhaust temp up and not 'overheat' the engine.

basically the ECU will sense the DPF is getting clogged, adjust the EGR valves, air intake and fuelling accordingly to get the exhaust up to the required temperature before commencing a regen.

Edited by alexp999
do not swear
Link to comment
Share on other sites

Please do not swear in your posts.

It is also not utter rubbish, it has been the advice of every mechanic I have spoken to about it and often recommended on here.

The engine overheats itself in the sense it increases the exhaust temps, non DPF cars never had a need to do this as they have nothing to burn off. Driving the car in top will keeps the revs low, around 1500 and not give the engine enough time to start burning off the DPF.

The quickest way is to help keep the revs high to warm up the engine quicker else you will need to do an hour or more for it to complete the regent itself.

The fan running is a tell tale sign the engine is trying to do a regen and the reason it runs is to stop the "overheating" process from damaging the engine.

Link to comment
Share on other sites


as per what jaguar have said in there x-type 2.2 auto with DPF.

i know its not a focus but the principle is the same!

'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 traveled and back-pressure signals from the differential pressure sensor.

Active regeneration generally occurs every 370 to 1250 miles (600 to 2000km) 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 an additional trigger, which is used as backup 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 estimated cumulative particulate emissions since the last active regeneration event.

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:

  • Retarding the main injection timing
  • Reducing intake boost pressure levels
  • Activation of the inlet throttle
  • Introducing post-injection of fuel after the pilot and main fuel injections have occurred.

Control of the post-injection 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 1 or 2 post-injections of fuel:

  • The first post-injection of fuel burns 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 un-burnt 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 200°C (392°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 760°C (1400°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 re-circulation (EGR) valve is closed. The use of EGR decreases the exhaust gas temperature and therefore prevents the optimum DPF temperature being achieved
  • The glow plugs are occasionally activated to provide additional heat to assist in raising the DPF temperature

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 the Jaguar approved diagnostic system to the vehicle, which will perform an automated static regeneration procedure to clean the DPF.

Diesel Particulate Filter Control

The DPF requires constant monitoring to ensure that it is operating at its optimum efficiency and does not become blocked. The ECM contains DPF software, which controls the monitoring and operation of the DPF system and also monitors other vehicle data to determine regeneration periods and service intervals.

The DPF software can be divided into 3 separate control software modules; a DPF supervisor module, a DPF fuel management module and a DPF air management module.

These 3 modules are controlled by a fourth software module known as the DPF co-ordinator module. The co-ordinator module manages the operation of the other modules when an active regeneration is requested. The DPF supervisor module is a sub-system of the DPF co-ordinator module.

DPF Fuel Management Module

The DPF fuel management module controls the following functions:

  • Timing and quantity of the 4 split injections per stroke (pilot, main and 2 post injections)
  • Injection pressure and the transition between the 3 different calibration levels of injection

The above functions are dependant on the condition of the catalytic converter and the DPF.

The controlled injection determines the required injection level in addition to measuring the activity of the catalytic converter and the DPF. The fuel management calculates the quantity and timing for the 4-split injections, for each of the 3 calibration levels for injection pressure, and also manages the transition between the levels.

The 2 post injections are required to separate the functionality of increasing in-cylinder gas temperatures and the production of hydrocarbons. The first post injection is used to generate the higher in-cylinder gas temperature while simultaneously retaining the same engine torque output produced during normal (non-regeneration) engine operation. The second post injection is used to generate hydrocarbons by allowing un-burnt fuel into the catalytic converter without producing increased engine torque.

DPF Air Management Module

The DPF air management module controls the following functions:

  • EGR control
  • Turbocharger boost pressure control
  • Exhaust Air Fuel Ratio (AFR) control

During active regeneration, the EGR operation is disabled and the closed-loop activation of the turbocharger boost controller is calculated. The air management module controls the air in the intake manifold to a predetermined level of pressure. This control is required to achieve the correct in-cylinder conditions for stable and robust combustion of the post-injected fuel.

The module controls the exhaust AFR by actuating the EGR throttle.

DPF Co-ordinator Module

The DPF co-ordinator module reacts to a regeneration request from the supervisor module by initiating and co-ordinating the following DPF regeneration requests:

  • EGR cut-off
  • Turbocharger boost pressure control
  • Engine load increase
  • Control of air pressure in the intake manifold
  • Fuel injection control

When the supervisor module issues a regeneration request, the co-ordinator module manages the change over to the regeneration specific settings. The change over occurs during an accelerator pedal release manoeuver from the driver or after a calibrated waiting time.'

Link to comment
Share on other sites

Before a costly bill it can be worth trying to clear the dpf yourself which will require more than letting the ECU try to do its thing.

By keeping the revs high not only do you raise temps but also increase the pressure and air flow through the exhaust which should help clear the dpf.

I have no doubt the ECU does all sorts of clever things to help the process, but in the sense of giving some advice its simplest to say that you need to get the engine hot and give it a blast.

All the eco driving and trying to attain quoted mpg figures is not good for the modern engines. They like being ragged every now and then to keep them clear. My dads driving instruction car was a prime example but that's a story for another thread :)

Link to comment
Share on other sites

Nanak,

The advise offered here is not utter rubbish, its a matter of opinion. The car will befall no harm in doing 70 in third gear, anymore than the car will suffer doing 70 in top gear. Its a means of catalysing the DPF clearout, and the hotter you get the exhaust, the better for the DPF.

Whilst the premise of the DPF management resides the same, you must consider that the likes of the ECU programming and the general car behaviour will differ between the brands. Many people on this forum have done high revs to assist with the passive regeneration, and in most circumstances, they have benefited from the experience. Others like yourself, who drive at 70mph in top gear this will work perfectly fine for, but you must consider that all cars are not the same, your DPF may be lightly sooted, whereas someone elses may be choked.

At the end of the day, anyone who wishes to try and passively regenerate can try either 70 in top gear, or 70 at high revs (third gear). Neither answer is more correct than the other, but it is down to anyone who needs to clear their DPF to do whichever method they prefer.

  • Like 1
Link to comment
Share on other sites

Thanks but I think you have missed the point. I do regular motorway driving so I don't think filter is a problem. Although the engine fan is on, the temperature gauge on the dashboard is showing normal. I believe it is somehow connected to the climate control as on the last occasion outside temperature was showing 27C as car had been parked in the sun. This figure didn't come down as you would expect once I moved off. I had to turn the set temperaure in the car up as too much cold air was entering. Where does the climate control dump the hot air? Could this be the problem

Link to comment
Share on other sites

When u go to rhe mechanics and they do a forced regen it takes the car to 3000 rpm for 15 mins after its warmed up enough, so if ford set a programme for that at that rpm range to clear it out, it must be utyer rubbish :/

Link to comment
Share on other sites

Thanks but I think you have missed the point. I do regular motorway driving so I don't think filter is a problem. Although the engine fan is on, the temperature gauge on the dashboard is showing normal. I believe it is somehow connected to the climate control as on the last occasion outside temperature was showing 27C as car had been parked in the sun. This figure didn't come down as you would expect once I moved off. I had to turn the set temperaure in the car up as too much cold air was entering. Where does the climate control dump the hot air? Could this be the problem

I think you have sussed this out yourself.

Running air con will make the fan come on.

To prove the theory, just turn the air con off for your next trip. Not as comfortable but will give you an answer.

Link to comment
Share on other sites

Thanks for that, the only problem being that it's not a consistent problem it's intermittant. There is no pattern or common factor as to when it occurs. Climate control is usually on all the time. It happened for the first time 2 months ago then twice in the last week, There is no sign or indication that the fan is on until you stop as you can't hear it in the car.

Link to comment
Share on other sites

I don't think the fan is on permanently. Think it cycles on/off as needed.

Most times the fan is on at the end of my commute. Sometimes switch off the AC and wait a minute or 2 for the fan to stop.

Link to comment
Share on other sites

I also think it's AC related , on a similar note , if i do a long trip , towards the end of my trip i reduce my revs to help cool , when i pull up on the drive my fan also runs on.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share




×
×
  • Create New...

Forums


News


Membership