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Lumpy diesel idle

Discussion in 'A3/S3/Sportback (8P Chassis)' started by crazylegscrane, Aug 6, 2009.

  1. crazylegscrane
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    crazylegscrane Member

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    The missus' A3 2.0 TDI (my old one) has devloped a lumpy idle. When the car is sitting at idle it feels like it is alternating between 3 & 4 cylinders continuosly. It has been doing this for a while and she is also complaing of it not having enough 'pull' while she drives it. :(

    I don't remember it being like that when I last drove it regularly which was about a year ago. She drives it on a 20 mile round trip to work through london traffic but gives it a blast every now and then. She did also complain that it blew a load of black smoke out one day when having a little blast around the north circ.

    Anyone have any ideas? I'm thinking throw some injector cleaner into it and see what happens. :uhm:
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  2. kaz219
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    kaz219 Active Member

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  3. crazylegscrane
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    crazylegscrane Member

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    No haven't had the cambelt done recently

    I haven't lifted the bonnet and listened to it with the engine running but only really felt it as being lumpy while sitting in the car. I don't think it would be as loud as that though I can hear some similarites with the engine pitch changing.

    I take it this is your car, what was up with it then?
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  4. NJI161
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    NJI161 New Member

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    Did you find out why this was happening as mine is doing a similar thing when cold??:blow:
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  5. crazylegscrane
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    crazylegscrane Member

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    no didn't find out anything... put some injector cleaner into it and thought it was ok, it did seem better to me but after asking the wife just now she says its still lumpy.

    So jury is still out, though I'll have to go for a spin in it and see what its like
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  6. kaz219
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    kaz219 Active Member

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    The PD engine run balanced and when the cambelts done, they get the torsion wrong.

    The torsion timimg needs to be between +5 and -5 for it to run and +2 and -2 for it to run properly.

    The easiest way to check this is when the its juddery, put the AC on and if it goes away or gets better, the torsion will be out.

    You can check the torsion via vagcom too.

    It could also be a split hose/air leak, dodgy maf, dodgy temp sender, injectors too.
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  7. crazylegscrane
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    crazylegscrane Member

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    thanks for the info, I think it should go in for a cam belt change so I'll ask them to check if they can find anything wrong with it:thumbsup:
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  8. matt a
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    matt a Member

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    Audi are doing a nation wide deal on cam belts atm, £320 all in (parts, labour, VAT), which is pretty good, although when we took my wife's 140 TDI A3, it needed £700 of other jobs done!
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  9. AA3
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    AA3 New Member

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    The problem you're having sounds exactly like what was happening with mine, i was told it was the injectors by the garage that sold me the car, bought redex, wynns etc and didnt change, it turned out to be the throttle body was caked in sooty deposits, so they cleaned it and put a new oil temp sensor in it, seemed to fix it.
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  10. Scopse
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    Scopse New Member

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    I too have a lump idle on my 2.0TDI A3. But the engine management light is on with fault codes 19557, 19558 and 17075, which I assume as you haven't said anything about engine management light, yours is not on?

    Anyway, my lumpy idle is caused by jammed throttle body because of soot build up as AA3 has suggested but seeing as your engine management is not on I'm not 100% certain.
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