530i Juddering under acceleration

Discussion in '5 Series' started by essdeeay, Mar 11, 2019.

  1. essdeeay
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    essdeeay

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    I have a 2008 E61 530i and for the last 6 months it's been juddering under high load at revs between 1500-1800. When it happens, if I don't lift off and reduce the load it will give a temporary engine fault and will run like a dog for 2 minutes before the fault clears itself and runs normally again (until I put it under high load at low revs again).

    An interesting thing is that it doesn't happen if I use 99 RON fuel (Tesco Momentum). Any other type of fuel 95 or 97 it will still happen.

    The other interesting thing is that when I had the adaptations reset it was OK for a few days - even with 95 RON fuel, but only for a few days.

    Some time ago a garage that did some work on it told me that the swirl flaps were ready to fall off and that I'd need a complete new inlet manifold at £450 + fitting. I did some research and found that the petrol models (or this one anyway) doesn't have the swirl flaps like diesels - something different.

    Where do I go from here?
     
  2. kleynie
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    kleynie WARLORD Site Supporter

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    Auto or manual?
     
  3. slim_boy_fat
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    slim_boy_fat WARLORD Site Supporter

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    Welcome aboard, sd. :wavey:

    What mileage is on her? Have you read, or can you get, the fault codes read? A good Indy ought to be able to do it and at least it'd give you some pointers as to the cause - as opposed to stabbing in the dark.

    I have a pre-LCI e60, now on 132+k miles and use common or garden s/market fuel without any problems.
     
  4. essdeeay
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    essdeeay

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    Thanks for the replies, and the welcome! The car is an auto and it's on about 145k. When the Indy read the fault codes a few months back he said there was a bit of a misfire on one of the cylinders... possibly injector, or coil-related. He swapped something over to test but hasn't been back to re-read - that wasn't the reason he looked at the car before. Anyway, what gets me is how with the higher RON fuel, the problem at least 95% disappears... which to me rules out anything mechanical.
     
  5. kleynie
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    kleynie WARLORD Site Supporter

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    So you have the N53 engine. Could be the high pressure fuel pump, any of the coils (or all of them) or the NOx sensor. The latter is my best guess.

    Is it not very good on fuel?
     
    Last edited: Mar 11, 2019
  6. kleynie
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    kleynie WARLORD Site Supporter

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  7. essdeeay
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    essdeeay

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    I get 27 average, and the book is something like 36. I think I should be getting at least low 30s. What do other people get on this board? I've had the car for 18 months and it's always been around 27. If I'm super super careful I might get it to nudge 29, and it never seems to get as low as the 25s though, no matter how I drive. I suppose it's one of those things where you start with the easiest/cheapest possibility and work from there.
     
  8. essdeeay
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    essdeeay

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  9. kleynie
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    kleynie WARLORD Site Supporter

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    If the NOx sensor has failed it will affect the mpg, this happened on my old N53 and I was getting 25mpg max. Yours doesn’t sound too bad, but these engines are very fuel efficient if running correctly. Trouble is the sensors are £300!
    You need to read the OBD codes as that will tell you before spending anything on expensive components.
     
  10. Richyroos
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    Richyroos

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    Have you checked the spark plugs? If they are worn, that could possibly explain the better running with higher octane fuel, the higher octane will burn a little better and be slightly easier to ignite - that's my two penneth amyway! I haven't had a petrol BM for a while, but if I recall, the spark plug change interval is surprisingly long, and the electrodes do wear on plugs - worth a look I would have thought.
     

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