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

engine struggling for temp on a run,

Discussion in 'A6/S6/Allroad forum (C5 Chassis)' started by Carlisle v6 tdi, Apr 22, 2014.

  1. Carlisle v6 tdi
    Offline

    Carlisle v6 tdi New Member

    Joined:
    Apr 7, 2014
    Messages:
    25
    Likes Received:
    2
    [Apr 22, 2014]
    hi, after searching the site I've found a few similar problems others have had, but not quite the same as mine,
    I've noticed that both my oil and water temps don't seem to move a lot, on a good motorway run I've seen 70 deg on both, but day to day they barely move, or at best register just above 60, heater seems to work but not boiling hot air at any point.
    I'm guessing a dead stat but just wanted to have it confirmed before I part with the cash lol

    could this have caused any issues engine wise as I've my suspicions its been like this for a while with the previous owner
    #1
  2. B5 BIKER
    Offline

    B5 BIKER Member

    Joined:
    Jul 24, 2011
    Messages:
    251
    Likes Received:
    16
    [Apr 22, 2014]
    Try the coolant temp sensor first.
    I had the same symptoms and they were gone as soon as I replaced it. Had same issues on a b5 A4 also before
    #2
    Carlisle v6 tdi likes this.
  3. Carlisle v6 tdi
    Offline

    Carlisle v6 tdi New Member

    Joined:
    Apr 7, 2014
    Messages:
    25
    Likes Received:
    2
    [Apr 23, 2014]
    cheers fella, I know in my heart of hearts its the right call, just wanted a second opinion as I said lol.
    now if only I could prise my wallet open lmao

    any idea on cost of genuine vag parts v's ebay specials??
    #3
  4. wesmaster
    Offline

    wesmaster Member

    Joined:
    Apr 22, 2012
    Messages:
    299
    Likes Received:
    18
    [Apr 23, 2014]
    If the oil temp is also low(less than70-80) then I would put money on the thermostat.
    Speak to adamss24.
    #4
  5. BlackQuat
    Offline

    BlackQuat Well-Known Member VCDS Map User

    Joined:
    Nov 24, 2009
    Messages:
    1,830
    Likes Received:
    45
    [Apr 23, 2014]
    Personally I'd do the thermostat and temp sensor at the same time with genuine parts. Piece of mind and the cost is fairly low.
    #5
  6. B5 BIKER
    Offline

    B5 BIKER Member

    Joined:
    Jul 24, 2011
    Messages:
    251
    Likes Received:
    16
    [Apr 23, 2014]
    I wouldn't bother with the eBay cheapo ones to be honest.
    Bought mine from a dealer over here who does the febi ones nice and reasonable, and hasn't given me any trouble since.
    Not sure where the thermostat is located on the the v6, would be handy if anyone had a pic for future reference
    #6
  7. ms1083
    Offline

    ms1083 Member

    Joined:
    Dec 26, 2010
    Messages:
    136
    Likes Received:
    4
    [Apr 23, 2014]
    Assuming you are talking about the 2.5 v6 TDI. The thermostat is located behind the timing belt so to change it you have to take auxillary belt off & timing belts off. Bit of a job really, worth replacing along with waterpump at timing belt change.

    Temp sensor easy to replace & quite cheap - about £8. located on top of engine near the front, quite obvious.
    #7
    B5 BIKER likes this.
  8. quattrojames
    Offline

    quattrojames Moderator Staff Member Moderator

    Joined:
    Mar 28, 2008
    Messages:
    13,973
    Likes Received:
    514
    [Apr 23, 2014]
    When I did my 2.5 CTS it was £30 with a litre of coolant.

    As mentioned, thermostat is a front off job. Needs new timing gear etc so you're looking at typically £500 ish with genuine parts.
    #8
  9. quattrojames
    Offline

    quattrojames Moderator Staff Member Moderator

    Joined:
    Mar 28, 2008
    Messages:
    13,973
    Likes Received:
    514
  10. Carlisle v6 tdi
    Offline

    Carlisle v6 tdi New Member

    Joined:
    Apr 7, 2014
    Messages:
    25
    Likes Received:
    2
    [Apr 23, 2014]
    Cheers James.
    I'll look into it.
    Was kinda hoping it would be on the top of the block somewhere but what to hoo it's gonna have to be done lol.
    Pretty sure cam belt and pump haven't long been done so saving cash already :0)
    #10
  11. BlackQuat
    Offline

    BlackQuat Well-Known Member VCDS Map User

    Joined:
    Nov 24, 2009
    Messages:
    1,830
    Likes Received:
    45
    [Apr 24, 2014]
    Never even thought it would be a V6 TDI. Fingers crossed it's the sensor then!
    #11
  12. Carlisle v6 tdi
    Offline

    Carlisle v6 tdi New Member

    Joined:
    Apr 7, 2014
    Messages:
    25
    Likes Received:
    2
    [Apr 24, 2014]
    Not sure it would be the sensor as oil temp is low too, am guessing thermostat, explains why previous owner was happy to snap up a ropey trade in. Cash is tight atm so scraggs inline adaption is looking favourable, especially as mot is almost due and I doubt she will manage the emissions test with a cold lump.
    Purely a stop gap measure though before the purists jump on me lol, I figures an inline unit can be reverted to a straight through configuration when the time comes.
    #12
  13. YSN
    Offline

    YSN Member

    Joined:
    Sep 17, 2013
    Messages:
    93
    Likes Received:
    3
    [Apr 24, 2014]
    I had a similar problem on my 1.9 Tdi and replaced the old sticky thermostat and the engine sees 90 degrees and stays there.
    #13
  14. Carlisle v6 tdi
    Offline

    Carlisle v6 tdi New Member

    Joined:
    Apr 7, 2014
    Messages:
    25
    Likes Received:
    2
    [Apr 27, 2014]
    I've just had a suggestion that may work,
    Full rad flush and coolant change may unstick the stat, got to be worth a try, Damn sight easier than changing it, again only a temp measure.
    #14
  15. himbigchief
    Offline

    himbigchief New Member

    Joined:
    Jul 27, 2011
    Messages:
    6
    Likes Received:
    0
    [May 22, 2014]
    I've got similar issues with an Allroad I've just bought and I am suspecting that the clutch on the viscous fan is seized meaning it is running at full rpm all the time. May be worth looking into that if the temp sensor doesn't fix it, before the expense of the thermostat change.
    #15
  16. BlackQuat
    Offline

    BlackQuat Well-Known Member VCDS Map User

    Joined:
    Nov 24, 2009
    Messages:
    1,830
    Likes Received:
    45
    [May 22, 2014]
    Even if the fan is running all the time. The thermostat should close to stop over cooling.
    #16
  17. myth
    Offline

    myth Member

    Joined:
    Dec 15, 2012
    Messages:
    142
    Likes Received:
    5
    [May 22, 2014]
    You can test the viscous fan very easy: with the engine stopped, rotate the fan blades. If it moves ( you should feel a little friction), then it's all ok.

    If you plan to change the viscous fan, you are already halfway to change the thermostat. Also, BlackQuat is right. Even at full speed, your temp should be at 90.

    To test your thermostat: after starting the engine, drive until the temp needle starts moving. Open the hood and put your hand on the coolant hose circled in the picture. If it's warm/hot, then it's the thermostat.

    Attached Files:

    #17
  18. Carlisle v6 tdi
    Offline

    Carlisle v6 tdi New Member

    Joined:
    Apr 7, 2014
    Messages:
    25
    Likes Received:
    2
    [May 25, 2014]
    Cheers for the advise guys, seems it's the dreaded thermostat after all. Can't afford to swap it out just at the minute unless I can aquire the cam tool then I'll do it myself. As a temp measure I have a (cringe) board between the rads which is helping vastly, almost getting to temp on a warm day lol.
    As soon as funds allow I'll be looking to complete the work and to also drop her oil and sort a bodged repair on the sump that is weeping a little.
    Oh and sort the rear tailgate light board which is leaking water in onto the fog light harness, half hearted attempt today was fruitless, going to rape a scrap car for newer parts to replace the corroded items on mine.
    #18
  19. BlackQuat
    Offline

    BlackQuat Well-Known Member VCDS Map User

    Joined:
    Nov 24, 2009
    Messages:
    1,830
    Likes Received:
    45
    [Jun 7, 2014]
    I will lend you the cam locking tools if you need them.
    #19
  20. Carlisle v6 tdi
    Offline

    Carlisle v6 tdi New Member

    Joined:
    Apr 7, 2014
    Messages:
    25
    Likes Received:
    2
    [Jun 8, 2014]
    Fantastic I'd really appreciate that, it's the only thing stopping me doing the work myself really, I'll pm you.
    Cheers fella.
    #20

Share This Page