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MPG gone aweful suddenly.

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by AudiLeon, May 3, 2011.

  1. AudiLeon

    AudiLeon Well-Known Member
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    The mpg on my 2.5 tdi has suddenly gone aweful. I used to constantly see 38mpg, 35 if i was a naughty boy occasionally.
    Recently, when filling up and working it out. It's always on 31mpg.
    MAF? Temp sensor?

    Any tests using vcds worth doing?
     
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  3. quattrojames

    quattrojames Moderator
    Staff Member Moderator Audi A6 Audi Avant Owner Group

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    I take it you've scanned it and no fault codes?
     
  4. AudiLeon

    AudiLeon Well-Known Member
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    I've done a scan on the engine, only fault is an engine code James.
    I did notice theres a 4 degrees temp difference between engine and instrument temps. Does that sound normal?
     
  5. Avant4me

    Avant4me The're Graphite not black!!

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    4 degrees is about right, the gauge is never going to be accurate.
     
  6. audigeezA4

    audigeezA4 Member

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    i have already accepted that the mpg on mine is never gonna be much more than what i am getting now, with a mixture of motorway and town driving i get 30.91mpg working it out manually, however, the dis states 24.8mpg on the 2 setting- so clearly my dis is completely inaccurate, i have even calmed down with my driving style but alas no effect.
     
  7. AudiLeon

    AudiLeon Well-Known Member
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    Really odd, as when I took it to FortWilliam, I got 45mpg. That's worked out at the pumps too.
     
  8. vinesh

    vinesh Member

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    Hi,

    Have you checked for boost leaks.

    Is yours a auto or manual?
     
  9. audigeezA4

    audigeezA4 Member

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    Blimey, 45 would be nice. I thought 30-35 was the norm anyway? I have only got 64k on the clock with fdsh, 53 plate,Manual so i thought i would get betta mpg than say a higher mileage. I recall someone saying cleaning the injectors, replacing air/fuel filters would help which i will get roubd to doing mine- one day.
     
  10. AudiLeon

    AudiLeon Well-Known Member
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    Mines a manual.
    When I said the difference in temps. I meant on vcds. Logging into instruments and engine. The engine temps are different.
     
  11. silversurfer

    silversurfer Member

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    Mine mates Diesel BMW had a similar issue, and he's just had to get a new turbo as the oil pipe was blocked :)

    This also didn't show up on the diagnostics before hand.
     
  12. Jama665

    Jama665 Member

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    try some redex or similar. dirty injectors are not good for diesels mpg. easy to do and could sovle the issue.
     

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