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MPG gone aweful suddenly.

AudiLeon May 3, 2011

  1. AudiLeon

    AudiLeon Well-Known Member VCDS Map User

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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?
     
  2. 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?
     
  3. AudiLeon

    AudiLeon Well-Known Member VCDS Map User

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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?
     
  4. Avant4me

    Avant4me The're Graphite not black!!

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    4 degrees is about right, the gauge is never going to be accurate.
     
  5. 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.
     
  6. AudiLeon

    AudiLeon Well-Known Member VCDS Map User

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    Really odd, as when I took it to FortWilliam, I got 45mpg. That's worked out at the pumps too.
     
  7. vinesh

    vinesh Member

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    Hi,

    Have you checked for boost leaks.

    Is yours a auto or manual?
     
  8. 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.
     
  9. AudiLeon

    AudiLeon Well-Known Member VCDS Map User

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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.
     
  10. 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.
     
  11. 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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