1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

a4 1.9tdi cooling riddle part 2

yendall24 Nov 7, 2008

  1. yendall24

    yendall24 Member

    571
    8
    18
    hi on saturday i replaced my thermostat and anti freeze because my car was running cool it rarely reached 70c and taking too long to warm up. it now runs spot on 90c and the oil temp is warmer than i have seen before so you would think happy days but no because it is taking even longer to warm up now. its taking about 7 miles before the temp gauge even begins to move i know it does not start registering until it reaches 60c but 5 of those miles are on the motorway i would expect it to warm up quicker than that . now the only thing i think i might have got wrong when changing the thermostat is putting the O ring on the wrong side ie i put the stat in then the O ring would this make a difference my car is a 1.9tdi pd 2001 x reg
     
  2. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    17,956
    701
    113
    Are you saying the coolant takes 7 miles to register on the guage? Sounds like a little longer than you'd expect, its only maybe 2-3miles before we get onto the motorway in the morning and the guage is usually half way to the 90 mark by then, although ours is a petrol

    Perhaps your having coolant getting past the stat when its closed, meaning it takes longer to heat up?
     
  3. yendall24

    yendall24 Member

    571
    8
    18
    yes theres something not quite right i am going to empty the coolant and try again. i could do with someone with the same car as me letting me know how long there car takes to reach 90c this is the first 1.9tdi i have owned and it as had a cooling problem since i bought it so i have nothing to gauge it by. but 7 miles when the weathers not that cold seems too long to me
     
  4. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    17,956
    701
    113
    aye it does to me too, although diesels do run pretty cool when they;re not under load, and sitting on a motorway crusing at 70 will probably only be using 20hp or so, so it may be normal.

    I'm sure someone else with a TDI will be able to advise the time theirs takes to warm up
     
  5. andybnwc

    andybnwc Member

    752
    0
    16
    im having a similar problem with my s4 seems to be taking a while i was on motorwy the other day and come off again it was only registering about 80 it was -1 outside but im sure it used to run 91 all the time once warmed up,im also gonna change my water pump because of a noise could this be a related problem
     
  6. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    17,956
    701
    113
    andy the guage on all B5's shows 90 at anything between 75 and 105c iirc. The idea being it sits at 90 within the normal range of operation, so you can tell if its suddenly running abnormally as the guage will have moved from its usual upright position.

    If the guage is only indicating 80 then either the guage is faulty, or the engine is infact running a lot cooler than that, probably more like 65-70c which would indicate a stuck thermostat
     
  7. andybnwc

    andybnwc Member

    752
    0
    16
    ok i if i do the thermostat will i have to remove waterpump aswell to check that for the noise?
     
  8. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    17,956
    701
    113
    you dont have to remove the water pump on a 1.8T to do the thermostat, but ive no idea on the S4 motor. Take a look at the diagrams on vag cat and you might be able to work out which parts need to come off.
     
  9. dieselfitter251

    dieselfitter251 Blow ma own trumpet?

    1,120
    0
    36
    It doesn't sound that much longer than my tdi (1.9tdi AFN engine) but I'm not sure. I'll pay attention when I set out tomorrow and let you know how long it takes to get up to running temp. FYI - my temp gauge needle is always a baw hair left of 90oC.
     
  10. neal

    neal Member

    30
    0
    6
    my b5 a4 1.9tdi afn engine temp gauge goes up to 90 but it soon comes back down again never stays at 90 on a run gauge tends to stay at 60-70 sometimes goes up to 90 but mostly stays at 65.does this means i have a dodgy thermostat as i thought this was normal????:unsure:
     
  11. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    17,956
    701
    113
    the guage should sit completely upright when upto temp

    If its dropping back then i'd guess the stat is getting weak and not closing enough to keep the temp under control!
     
  12. andybnwc

    andybnwc Member

    752
    0
    16
    is this not safe on a long journey then?
     
  13. dieselfitter251

    dieselfitter251 Blow ma own trumpet?

    1,120
    0
    36
    Hey, Yendall24.
    I checked my car out with you in mind today. The 'ole girl hadn't moved in a day. It took almost 7miles exact to get coolant up to 90oC and the oil sat at the usual 80oC. My guages don't move no matter how I drive or what the temp is doing outside.
    Hope this was of help.
     
  14. yendall24

    yendall24 Member

    571
    8
    18
    thanks for that the problem with my car is the gauge only starts to move after seven mile if it was up to 90 at seven mile i would be happy with that
     
  15. dieselfitter251

    dieselfitter251 Blow ma own trumpet?

    1,120
    0
    36
    Ah, gotcha. I'm not sure what else it could be other than a faulty guage or what else has been mentioned in this post. Good luck!
     
  16. ALPINE

    ALPINE Yes its diesel, now cry u lost

    3,093
    3
    36
    Since i changed my engine both my gauges now work!! :) yay!! but i notice mine also take a good while b4 they move. ill sit at 70-80 untill i stop in traffic then it will sit at 90. I also thought this was normal.

    i know mine is petrol, but no point starting another thread eh.

    my oil sits at about 70c.

    This not normal then ??
     
  17. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    17,956
    701
    113
    alpine: nope sounds like your stat is stuck open, mine was exactly the same when i got the car, 70-80 when driving dropping to 60 cruising on the motorway on a cold day, and only climbing to 90 when stationary. Car also did ***** to the gallon. Swapped the stat out and now it comes round to 90 within a few miles and doesnt move.

    Seen as the guage shows 90 at anything between 75 and 105, the fact its not showing 90 means that its <75c which also explains why your oil is only at 70. Oil does take a LONG time to warm up, but thats normal with any car. think its about 10mins before ours settles.
     

Share This Page