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Warm up time

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by stu_m, Dec 17, 2011.

  1. stu_m
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    stu_m Well-Known Member VCDS Map User

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    [Dec 17, 2011]
    I have a 1.9 diesel that to me seems forever to warm up the missus can drive to work about 8 miles away its a nice steady drive with about 2 miles of 60 mph the rest is 30's and 40's with the heating on the needle won't get to above 70 heating off it will get to 90

    It's had a new stat and temp sensor last year

    Is this about normal as I do know a diesel runs cooler then petrol cars
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  3. ScottD3
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    ScottD3 I want your faulty electronics Supporter

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    [Dec 17, 2011]
    Seems fine to me.
    My B5 TDI is the same.
    7mile drive to the ferry port, sit there for 5mins or so with the engine running till the ferry comes in and you can watch the needle drop as you wait.
    Drive on to the ferry and it warms up a little.


    I think the wind chill factor of driving cools the engine down more than it can heat it up.
    At least we never have to worry about our cars over heating in the winter. :)
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  4. simon.m
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    simon.m Active Member

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    [Dec 17, 2011]
    I'd say it seems fine this has been covered nearly every winter at some point my tdi will take a good 20 minutes of town driving to hit 90c and stay there you have to take into account we are using the heat. To warm are selfs first if you turn the heater down to 1 this will help with the time it takes. So I'd not worry about it mate seems fine
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  5. simon.m
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    simon.m Active Member

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    [Dec 17, 2011]
    I'm also told by many people diesel self cool. To a point so if left on tick oer will stay the same temp or drop a bit
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  6. stu_m
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    stu_m Well-Known Member VCDS Map User

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    [Dec 17, 2011]
    Sounds good to me then

    Yeah I know a diesel cools itself but not that much that it won't warm up

    Might try the cardboard on the rad to see if it warms up faster
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  7. ScottD3
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    ScottD3 I want your faulty electronics Supporter

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    [Dec 17, 2011]
    Then what?
    Stop, get out, remove cardboard and carry on your journey?
    Do a search, there is many posts about it on here and I don't think its any thing to worry about.
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  8. simon.m
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    simon.m Active Member

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    [Dec 17, 2011]
    My car if I just start it up will not move the temp gage well not that I can see. Evan if I leave it 15 minutes on tick over but as soon as I drive it will move
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  9. stu_m
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    stu_m Well-Known Member VCDS Map User

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    [Dec 17, 2011]
    no

    you cover half the rad up to stop the air flow in to the engine bay and it warms up faster leave the bottom half uncovered and when the stat opens there is more then enough cold air over that section of the rad to stop the car over heating

    used to have to do it to my dads landrover as that was a right cold arse
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  10. stu_m
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    stu_m Well-Known Member VCDS Map User

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    [Dec 17, 2011]
    yeah mines the same but just thought it was a bit slow to warm up on a 20 - 25 min drive even with heating off and not stuck in traffic

    but if its normal its normal :)
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  11. marktdisport
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    marktdisport Active Member

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    [Dec 17, 2011]
    mines the same stu, i aint to worried as the heaters blow hot within a minute or two of start up so its running fine, just the gauge spends more time on 70 than 90 unless a red hot day...... time to worry when it goes the other way lol
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  12. simon.m
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    simon.m Active Member

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    [Dec 17, 2011]
    This is true to hot is more of a worry . I read that the car keeps the heat for passengers first then the engine witch is a good thing as I hat the cold :tocktock:
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  13. white.akita
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    white.akita Member

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    [Dec 17, 2011]
    same situation, i recently replaced my cts and thermostat and has been fine but since the cold weather it takes forever for the temp needle to point straight up at 90 degrees.
    these engines also seem to cool down very very quick after they are turned off.
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  14. yendall24
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    yendall24 Member

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    [Dec 19, 2011]
    i would not of thought covering half the rad with cardboard would make the engine warm up faster . because until the engine is warm enough to make the thermostat open there is no circulation through the rad . but it will help to keep the temp up once the thermostat as opened
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  15. stu_m
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    stu_m Well-Known Member VCDS Map User

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    [Dec 19, 2011]
    It reduces air flow to the engine bay so you get a warmer engine bay and hopefully aids warm up

    Also I have noticed today that the top hose is warm within about 5 mins of running so there must be some sort of flow for that to warm up!
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  16. Mike B
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    Mike B Member

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    [Dec 19, 2011]
    A good stat should allow quick warm up even when very cold.I think they vary even when new and judging by the cheap one my son fitted to his S3 3 mos ago and which is now stuck open its best to use genuine parts only.My 2.5Tdi had a good one fitted this year and she blows warm air at me after 2/3 miles.Blanking off part of the rad can be risky and I wouldnt use cardboard
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  17. stu_m
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    stu_m Well-Known Member VCDS Map User

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    [Dec 19, 2011]
    Don't get me wrong I get warm air out the blower's after a few mins but the car doesn't reach operating temp

    I want fast warm up to save my fuel!

    Covering the rad is only risky if you can't read a temp gauge as common sense would tell you your not getting enough air flow if the temp starts rising above normal

    Well I'm going to trail it anyway to see if it does make any difference I will report back
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  18. ScottD3
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    ScottD3 I want your faulty electronics Supporter

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    [Dec 19, 2011]
    You're going to put card board in front of rad?
    Apart from the issue of stopping the rad from doing a very important job.
    you also run the risk of the cardboard getting damp, breaking up, blocking or damaging the fins with on your radiator, condenser (you guys still have that in front of the rad right?) and any other cooling device you have.
    Also the crappy ass job of picking up broken, soggy cardboard from with in your engine back, bumper and any where else it can go.
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  19. mikeh126
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    mikeh126 Member

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    [Dec 19, 2011]
    I wouldn't put cardboard in front of the rad for the reasons mentioned by scott b5.
    FWIW, diesels take longer to warm up than petrols, and if you are getting warm air out of the vents within a couple of miles of start up, I wouldn't worry - it's doing it's job.
    Although I have the 2.5tdi, mine behaves much in the same way as yours. I was watching the temp needle today - and it took about 4 miles to reach 90C.
    BUT, gently wafting along at 40mph, flat road, empty car, in 6th gear, it was only doing about 1100 revs. So the engine isn't doing much work for it to heat up quickly - it's only just above tickover - but warm air out of the vents after about a mile.
    Putting cardboard in front of the rad won't improve your mpg, IMHO.
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  20. Tooks
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    Tooks Active Member

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    [Dec 20, 2011]
    Definitely no to the cardboard thing too, there just isn't any need for that these days.

    If the car is taking a long time to warm up, then the thermostat isn't working properly.

    Yes, diesels are efficient, but not that efficient, and the cooling system is designed to get the engine up to operating temp quickly, and then keep it there regardless of whether it's sitting in traffic or on the motorway and whether it's warm or cold outside.

    When I was running my 1.9tdi, the needle was always at 90 within 4 or 5 miles, and never moved off 90 even in traffic. The only time it didn't do that is when the thermostat was broken. It was at 85/90 when charging down the A1, and then dropped down to 70 when in traffic. A new stat got it working properly again.
    Last edited: Dec 20, 2011
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  21. stu_m
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    stu_m Well-Known Member VCDS Map User

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    [Dec 20, 2011]
    like I say above it goes on a run that is around 7-8 miles each day and never reaches 90 unless the heating is turned off and it will reach just under 90 just as the missus gets to work

    when i take her with the heating on it will reach 90 halfway back home so your talking a good 12 mile run of 30-40 and a run on a 60 never stopped for more then a few seconds which is only at round abouts so its actually worked too so should warm up rather quick

    think i will get a new stat as I know it souldn't take that long to warm up! it could even be the temp sensor playing up!

    anyway yes i know not to use cardboard its a figure of speech as people used to use card wrapped in tin foil to stop it falling apart i had a nice piece of sheet steel that fits between the 2 rads only covers about 7 inch of the top half so i tried it this morning and the car under the same driving conditions at 4°c this morning was at full temp within 4 miles so this proves that covering the top section does indeed warm the car up quicker

    i will buy a new stat and temp sensor from audi as i have a feeling that mine could be on the way out it could be a case that the stat is just allowing some coolant by and taking a bit longer to warm up

    i have also noticed that once the car does get to 90 if you give it the beans the temp actually goes down to 70 ish
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  22. Mike B
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    Mike B Member

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    [Dec 20, 2011]
    There is no harm in blanking off part of the rad if you are careful.Used to be common practice many years ago and I still do it with my 70s Spitfire in winter otherwise it would never warm up.Best material is the plastic reflector sheet for behind household rads wont tear or rattle and is easy to slot in and out but you still need a better stat.Mine gets to 90 in about 3/4 miles and stays there
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