DPF sensor

Discussion in 'Tech/Mech General' started by greygit, Sep 5, 2014.

  1. greygit

    greygit Read Only Funster

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    Our van, which is 22 moths old, has just had the engine warning light come on and after two days of work by the a Fiat garage and the involvement of Fiat Technical the fault was found to be the DPF sensor. I'm trying to find out if this is a common fault with motorhomes as the garage told me it was.......if common why did it take two days to find the fault and why did Fiat Technical have to get involved?

    Can I ask if anyone else has had this problem? As I thought if it is then forewarned is forearmed.
     
  2. hilldweller

    hilldweller Funster Life Member

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    Don't know if this applies but the local friendly MOT guy I was talking to said these days they get a lot turning up with particle filter warning light on, he tells them to go and buy top brand diesel fuel and run a few tanks through, the light usually goes off. So he is saying use supermarket at your peril with a modern diesel.
     
  3. Badknee

    Badknee Funster

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    Sorry but I disagree with that comment, we have run all our vehicles on s/market fuel for 100's of thousands of miles each and never had a warning light of any sort come on diesel related or not.
     
  4. Leltel

    Leltel Funster

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    We have just had the same problem on a 14 month old van that has travelled 10,ooo miles.
    Our Fiat garage said it was from not driving her hard enough :(
     
  5. Badknee

    Badknee Funster

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    Haha, what a load of tosh. Warning lights to tell you to thrash it, well you learn something new every day lol.
     
  6. RS_rob

    RS_rob Funster

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    Under normal operating conditions a long run is needed to clean the filter, generally it's short local runs that cause the light to come on.
     
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  7. Badknee

    Badknee Funster

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    Ah yes, I can agree with that, perhaps he should have said your not driving it enough?
     
  8. andy63

    andy63 Funster

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    think the problem is industry related, ie not just to motorhomes , but any engine with the dpf system fitted..
    Peugeot had a load of problems with a lot of their cars years ago ,but so did all the manufacturers , and ive heard the same thing from ford , ie you need to take it on the motorway and give it a good thrash LOL...
    think they mean it has to be up to a good temperature before they burn off the crap, to put it bluntly .
    the worrying thing I think is if you start having the problems no one seems to be able to sort them out and they keep returning. know a few people who have just ended up getting rid of their cars rather than put up with on going emission related faults...
    ta andy
     
  9. Leltel

    Leltel Funster

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    It is to get the temperature up to burn off the crap, hubby did say that the way I drive none should build up :)
     
  10. John Laidler

    John Laidler Funster

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    I think there are some crossed wires here, not getting the engine hot enough and/or not giving the engine a bit of welly from time to time can lead to the DPF becoming blocked at which point the sensor will correctly indicate a fault. For vehicles which don't get a lot of hard use (i.e. the average MH as opposed to a delivery van) then the premium fuels are supposed to help and don't have to be used every trip.

    However, the OP reported a sensor fault so there was likely absolutely nothing wrong with the DPF.

    Why it took so long to fix may have been down to another fault such as a poor connection not allowing the diagnostics to find the fault correctly, or simply the well known problem of modern engines being such complicated beasts these days and the diagnostics not being 100% accurate.

    There are some new engines coming in which have the exhaust manifold integrated in the cylinder head with a close coupled DPF. Early indications are these engine don't suffer the same problems as current engines with the DPF some distance from the head. The idea is the DPF is subjected to much higher temperatures.
     
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  11. greygit

    greygit Read Only Funster

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    Actually I never told the whole story, originally the van went in for its first service and when I dropped it off and the mechanic drove it into the garage the receptionist asked me if I had recently disconnected the battery as the warning light was on?! I replied that the warning light was not on when I stopped it just now and the reply was, it's no problem we will switch it off. When I arrived at the prearranged time to collect the van I was told, we have not finished the service and we cannot switch off the engine management light. Another appointment was made so they could complete the service and rectify the warning light problem, again on collecting the van I was informed we have completed the service but we still can't switch off the light. Therefore, I left the van and, apparently, Fiat technical got involved until it was sorted out, a total of two days.

    One thing that really surprised me was that Fiat insists on three warm-up and cool down periods (three road tests) before the final check on the box of tricks before they consider the vehicle ok to use.......no wonder it takes so long!
     
  12. pappajohn

    pappajohn Funster Life Member

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    DPF filters are self cleaning but some require a higher speed than usual to increase the exhaust temperature to over 600°c to burn off the accumulated soot.
    Many engines do this automatically and no driver involvement is needed.

    If it isnt done or the auto function doesnt kick in the warning light will eventually come on.

    A simple OBD11 reader will cancel the light but if the fault isnt removed (dpf regeneration) it will come back on.

    It is possible for the filter to become permanantly blocked if regen isnt performed soon enough.


    And it has nothing whatsoever to do with motorhomes specifically.
     
  13. John Laidler

    John Laidler Funster

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  14. Glandwr

    Glandwr Funster

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    As has been said DPF filters give problems. I spent a shedload of money trying to cure the warning light on a pug 307 after a while of ignoring the light it will go into limp mode. Cure in the end was to bash the guts out of the PDF physically and get a local computer whizz kid to remap the ECU so as to ignore the warning. Never looked back. Still passes the emissions on the MOT. It is however illegal as you are defrauding the revenue by having cheaper RFT than you should.

    Dick
     
  15. hilldweller

    hilldweller Funster Life Member

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    These manufacturers have no idea of running costs for the motorist.

    75,000 miles and they expect you to fit a new £1000 DPF. On a 75,000 motorhome, someone's aging pride and joy that's a lot of money.

    Special fluid. £200 to top up the additive tank at 70,000.

    Throw in a few timing belts.

    Are they deliberately making vehicles with a limited real world life ?
     
  16. John Laidler

    John Laidler Funster

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    No, it isn't the manufacturers, it is the requirement to meet emissions laws that drives this and I think the requirements were more stringent than technology could really manage but these new engines with in-head exhaust manifolds sound promising - but of course then legislators will keep shifting the goal posts - Euro 6 now and no doubt Euro 7 to follow in a few years.

    But I'm not sure where they get their £200 from, AdBlu is about 50p a litre wholesale price I thought - but not required by most (any?) MHs I think.
     
  17. hilldweller

    hilldweller Funster Life Member

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    Ah, but the gotcha is those who make the rules are politicians who rely on experts to do techie things. Now where do they find cutting edge technicians, working for manufacturers.

    I have seen the process where Manufacturer A has an edge, their techie sits on the rules committee, he pushes of 1.5%ppm knowing full well Manufacturer B can only manage 2.5%ppm thereby putting huge pressure on their competitor.

    So, I believe, this is how manufacturers are constantly working to screw more and more out of us.
     
  18. Clayton9

    Clayton9 Funster

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    On 28 june this year i was setting of from home on my 3 weeks holiday to Italy. As i pulled off my drive the engine management light came on. I called out the RAC who put it on diagnostic, did a forced regeneration which didn't clear the fault. So he said I had to take it to a fiat dealer. They said it was the PDF filter getting blocked. They changed the filter. My van was 2 years 6 months old, 23k on the clock and they said it gets blocked cause i do short runs!! If i was only doing short runs i wouldn't have that many miles on it. On the plus side they fixed it for free!!
    This is the second time i have had this problem and the first time i called the RAC he warned against supermarket fuel, and a not even a year later i get the same problem and thats not using supermarket fuel!!
     
  19. John Laidler

    John Laidler Funster

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    The AA report I linked to suggested one cause of this. High mileage doesn't really count if most of it is done with the engine just ticking over at low revs while you are doing 50 or 60.
     
  20. TerryL

    TerryL Funster

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    Just completed 50,000m, generally sticking to 55-60 mph (nearly always long runs mind) and always using supermarket fuel. If you believe everything above I should have "broken down" half a dozen times but nary a hiccup!

    Of course, that's done it now - next time out it'll probably pack up!
     
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