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Audi A4 1.9 TDI - Temperature never reaches 90 Degrees

jay786 Feb 22, 2012

  1. jay786

    jay786 Member

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    Hi People,

    For some reason the engine temperature never reaches 90 Degrees. its always on the 70 Degree mark or below to be honest.

    I only get heat from my heating system when im driving, not when im idle .. blows out cold air.
    Plus .. i get less air coming into the vents. When i open up all four vents or split the heat to the floor .. you cannot even feel anything thats coming out. Its as if its not sucking in enough air to give out.

    Please help

    Thanks
     
  2. kite

    kite Member VCDS Map User

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    I would change the thermostat
     
  3. samsam

    samsam Member

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    I would say it’s your temperature sensor easy to replace
     
  4. jay786

    jay786 Member

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    Shall i replace both or the thermostat first and then the temperature sensor
     
  5. marktdisport

    marktdisport Active Member

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    your problem is the thermostat m8 temp sensor will only tell the gauge to go to it's desired temp it's reading..... thermostat is stuck open causing it not not reach running temps in the first place......
    you may well be best to change both items as they dont cost that much to buy £25-35 ish for both
     
  6. jay786

    jay786 Member

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    Is there a guide on how to change it.
    THanks
     
  7. simon.m

    simon.m Active Member

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    its best to do both as they are both in the same housing when you take it off for the stat you will see the temp sensor
     
  8. jay786

    jay786 Member

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    Any pictures or how to do it .. i have bought the temp sensor as well as the thermostat
     
  9. quattrojames

    quattrojames Moderator Staff Member Moderator Audi A6 Audi Avant Owner Group

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  10. stu_m

    stu_m Well-Known Member VCDS Map User

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    You sure?

    My stat is at the front and my sensor is at the rear both opposite sides too
     
  11. simon.m

    simon.m Active Member

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    it says its on the rear on a tdi mate
     
  12. StuG808

    StuG808 1.9tdi130 Avant FailWheelDrive

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    Hmm, I'm replacing the only the thermostat on mine tonight. If I had read a bit more about the temp sensor I would have got that ready to change too. I'll see how it goes with just the thermostat change first.
     
  13. stu_m

    stu_m Well-Known Member VCDS Map User

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    The temp sensor is at the rear on mine and the stat is at the front behind the alternator

    Some engine codes could be different though mines an avb
     
  14. pink.teg

    pink.teg Member

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    Woo hoo
    best of luck !!
    Im doing both in the morning
    ready for the remap ......

    So may in the same. Boat !!!
     
  15. AudiLeon

    AudiLeon Well-Known Member VCDS Map User

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    Did our A6 last night. Easy job! 90 degrees after 12 mins
     
  16. stu_m

    stu_m Well-Known Member VCDS Map User

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    Is this after 12 mins of driving? It take the missus 30 mins to get to work and only just reaches temp this is with a newish stat! Maybe I have a duff stat!
     
  17. AudiLeon

    AudiLeon Well-Known Member VCDS Map User

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    Yeh bud, the wife took it to work today and she said by settle (12 mins away) it was at 90degrees and on the way home after 5 mins it was just coming off 60degrees and another 5 mins later it was hot.
    My v6 tdi is at full temp in less than 10 mins though, i think it has aux heating though.

    We fitted a new stat, temp sensor and new fluid.
     
  18. dolcevita4

    dolcevita4 Member

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    I'd do both in one go, it's cheap enough ! Apart from these two parts you will need coolant to top it up.
     
  19. dolcevita4

    dolcevita4 Member

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    my a4 1.9 tdi gets on temp after 7-8 mins.

    30 mins is way too long, i would check that out and have it fixed as it's pointless wasting money on fuel...
     
  20. AudiLeon

    AudiLeon Well-Known Member VCDS Map User

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    As above it needs sorting. The wife took it down to Chester the other day, 190+ mile round trip at 70 degrees. Ouch.
    It had the original black sensor on too. Gulp! MPG has been showing 46 on the dash, run back today showed 55mpg
     
  21. dolcevita4

    dolcevita4 Member

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    I mean if your handy with your tools it will cost you around 20 pound for the whole lot, so it's definately worth it.
     
  22. marktdisport

    marktdisport Active Member

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    have known a few spurious make thermostats to fail from new so may be worth investing in genuine imo...
     
  23. jay786

    jay786 Member

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    The temp sensor is on the rear ... what is it near .. my engine is 100bhp .. is that engine code AVB?
     
  24. simon.m

    simon.m Active Member

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    you have the same engine as me as you look down the back you can see it mate
     
  25. jay786

    jay786 Member

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    so for my model is the temp sensor and the stat in 2 different location?

    Is the temp sensor below the engine?
     
  26. simon.m

    simon.m Active Member

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    as far as i no it is in the same housing mate but i did not change mine when it was done so cant be 100% sure but nether of them are hard to change i think its nearer the drivers side near the top
     
  27. stu_m

    stu_m Well-Known Member VCDS Map User

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    Yes the temp sensor is on the left as you look at the engine drivers side right at the back it is hard to see

    And the stat is at the front right passenger side right behind the alternator just lower then it look for the bottom rad pipe and follow it to the engine

    And yes 100 bhp is avb engine code check your v5 to verify
     
  28. stu_m

    stu_m Well-Known Member VCDS Map User

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    Well I will be doing cam belt and water pump some time soon so I will change stat and sensor again while I'm at it this time I will get them from Audi
     
  29. simon.m

    simon.m Active Member

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    the book says its beneath an inlet elbow/cover on the left hand side of the cylinder block thats the haynes manual
     
  30. jay786

    jay786 Member

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    damn i bought mine from eurocar parts
     
  31. dolcevita4

    dolcevita4 Member

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    don't worry, i have mine from them and never had any problems.
     
  32. stu_m

    stu_m Well-Known Member VCDS Map User

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    left if your sat in the car thats the way haynes describes it ;-)
     
  33. simon.m

    simon.m Active Member

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    ha well its there some where hehehe
     
  34. pink.teg

    pink.teg Member

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    well well
    all done changed both parts this morning 30.mins max
    90'c now lets hope it dosen't over heat in traffic ......
    £48.72 from trade parts specialists that's a supplier to Audi
     
  35. StuG808

    StuG808 1.9tdi130 Avant FailWheelDrive

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    Did you have to drain the coolant to do the job? I didn't get round to doing mine as the service took most of the night (and also dealing with a snapped dipstick tube!).
     
  36. jay786

    jay786 Member

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    where on earth is the thermostat located on a 1.9 TDI 100bhp ... can't find it.
     
  37. jay786

    jay786 Member

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    i was told behind the alternator .. cannot see it .. do i need to take out my alternator?
     
  38. quattrojames

    quattrojames Moderator Staff Member Moderator Audi A6 Audi Avant Owner Group

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    I can't imagine it's that hard to find!

    But if you're really stuck I'll have a look on Elaswin for you tonight.
     
  39. jay786

    jay786 Member

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    [​IMG]

    Thats my engine bay .. someone please locate the thermostat.

    Thanks
     
  40. stu_m

    stu_m Well-Known Member VCDS Map User

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    As already said follow the bottom rad hose to the engine it will come to a plastic pipe remove this and your stat is in there
     

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