Depollution system Fault!

[aeroboy64]

Have now had my 08' c5 x7 69000 mls exclusive auto for 8 mths and has been great (apart from a faulty suspension pump),so on saturday had to get to B&Q for some plumbing bits and was behind a 15yr old fiesta with windows open and loud music playing,Stopped at lights and pulled alongside and when lights turned green car just refused to rev and DEPOLLUTION SYSTEM FAULT message appeared and an yellow engine symbol lit up!

Fast forward to yesterday and after googling problem it was either eolys fluid/maf sensor/fuel filter/turbo so was really s**t it and applied for a 2nd mortgage?,I always thought that diesel engines just needed a good blast down the motorway for half an hour to sort out the DPF ?

So with nothing to lose took the car up to speed limits on m'way for about 25 mins and it pulled like a train in all gears and when doing 30 mph near home i heard a slight whistling sound like a windows not fully shut which lasted about 10 mins and after letting engine cool restarted and no more fault messages and engine icon has gone out

Was surprised that i could'nt find info online to say drive it like a hire car and problem should fix itself,Got my plumbing plumbed so a good outcome.

[GiveMeABreak]

How do you generally drive it? - if it is short slow trips, stop and start traffic - the car won't get a chance to regenerate the particle filter. Over time it will clog and cause poor running. If it isn't rectified it will lead to reduced performance mode kicking in. It does tell you about the particle filter on page 33 of the handbook.

If it is the additive level then the SERVICE light with the Engine Management Light and a message "Particle Filter (FAP) additive level too low" will be displayed

If it is the particle filter clogging, it should display the service light with the message "Risk of saturation of particle Filter (FAP)" This is the one that gets displayed if it has run for long periods without the chance to regenerate and you should ensure it completes a regeneration cycle as soon as possible - similar to what you did - give it a good run at at least 37mph for at least 5 minutes according to the book - but may need slightly longer to ensure the engine is at running temperature.

[aeroboy64]

Its mainly 5 miles to work and 5 miles back and the oil and water are always up to temperature,The message was DEPOLLUTION SYSTEM FAULT and as mentioned earlier car has never run better.Would going for a spin at 50mph for 20mins every week do it good?

[Stickyfinger]

The ONLY time my X7 has done this was when it was cold and I had to "boot it".

5 miles will not get the system hot enough to regen, I would think the ECU will not initialise a regen on such sort a drive. So, 50/70 in 4th (or locked down in an auto) for 15 mins should.

[GiveMeABreak]

The problem is that eventually the particle filter will clog with ash from the regeneration process - that is inevitable and it means the filter will need cleaning out or replacing. How soon that happens will depend to some degree on how the car is run and whether the regeneration cycles are performed when needed. 5 miles is not a long run - barely enough time for the engine to get to operating temperature. The risk is that when it gets to temp, then decides it needs a regeneration cycle - you could of completed your journey and this prevents the operation. Then the cycle repeats on the next journey - so it may not be getting the chance to regenerate regularly as needed. Once the filter gets a soot load of about 70% it is likely the car will go into reduced performance mode and a regeneration cycle should be undertaken ASAP. At soot loading of about 85% and above it may no longer be possible to regenerate the filter and will likely need replacing or cleaning out.

[aeroboy64]

The problem is that eventually the particle filter will clog with ash from the regeneration process - that is inevitable and it means the filter will need cleaning out or replacing. How soon that happens will depend to some degree on how the car is run and whether the regeneration cycles are performed when needed. 5 miles is not a long run - barely enough time for the engine to get to operating temperature. The risk is that when it gets to temp, then decides it needs a regeneration cycle - you could of completed your journey and this prevents the operation. Then the cycle repeats on the next journey - so it may not be getting the chance to regenerate regularly as needed. Once the filter gets a soot load of about 70% it is likely the car will go into reduced performance mode and a regeneration cycle should be undertaken ASAP. At soot loading of about 85% and above it may no longer be possible to regenerate the filter and will likely need replacing or cleaning out.

As the DPF has just been recycled and should be clear would a 50-70mph for 30 mins once a week stop it from occuring again?Thanks for all the input so far i'm just happy i dodged a bullet this weekend.

[GiveMeABreak]

It's not the speed that's so important, but that you are running it long enough for the engine to warm up and then as 'Sticky' says keep it in 4th gear at about 50-70 mph for a good 10-15 mins once a week - especially if you do a lot of stop / start or short trips.

[Hell Razor5543]

If you can, you should take her out for a nice long motorway run every month or so, as this helps to keep the pipework clean. The DPF system can burn out the particulates, but it needs a certain degree of heat passing over it for long enough to burn them off. On some cars it may be possible to trigger a regen cycle with the car standing still, but there are safety concerns to be taken into account (I saw this done once, and the exhaust almost looked like it was a blast furnace; lots of smoke and sparks, occasional spits of flame. Very impressive, but it worked). A motorway run of 45 minutes or so (at motorway speeds, not M25 speeds!) should be long enough, as the engine will have got up to heat, and the DPF should then be able to regen itself.

[zs&tas]

Its not speed its engine load, mines poped up now and then, a few hard slip rd or off rb accelerations and it goes.
Never been a problem