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2.5tdi changing thermostat - whats involved?

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by mystic.bertie, Oct 27, 2011.

  1. mystic.bertie
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    mystic.bertie Member

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    i have read before that its a big job changing the thermostat on the 2.5tdi, i have the front of the car up on stands as im investigating why my alternator drive belt came off, so the carrier will be going into the service position.

    can the thermostat be changed without having to remove the timing belt and removing the service carrier??
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  2. Mike B
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    Mike B Member

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    The front has to come and most would replace the belts unless it had just been done when the stat s/b replaced anyway with the w/pump
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  3. mystic.bertie
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    mystic.bertie Member

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    thanks mike, the timing belt was done at 160,000 its now at 208,000, i want to avoid changing the timing belt as from what i have read the fuel pump timing needs done with vagcom after the belt has been fitted.

    im hoping i can change the thermostat and any other belts while im in there but leave the timing belt in tact, but im not sure what needs to be removed to get access to the thermostat.
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  4. swarcup
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    swarcup Active Member

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    Not a chance im afraid to say its buried behind the cambelts covered over by a plate next to the waterpump. There isnt the room to get it all out, Why change them now if they are ok? youve only another 20k before you have to do the belts anyway. I would just replace what has broken and leave the rest alone. You are correct with the fuel pump timing and vag-com. Adamss24 will be the right guy to advise you on this engine. When i watched him do my cambelts tensioners and all the other parts the car was always in the service position, the front can be hinged out if you want to see what you are doing but not necesary
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  5. mystic.bertie
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    mystic.bertie Member

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    hi mate. thanks for the reply. i never made it clear but the thermostat is faulty, the temp gauge is low and the heater air only gets luke warm. Its a high miler and not in great condition and its unlikely im gonna be keeping it long term, so i dont want to go spending lots of money on it or lots of time. I would rather fix the thermostat but if it means doing the timing belt too i may just leave it, what a crazy design, thanks audi.

    i dont mind so much tackling the timing belt if i need to but the fuel pump timing with vagcom is putting me off.
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  6. adamss24
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    adamss24 Active Member

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    There is a way to change the thermostat without replacing the cambelt but it needs slackening the LH Side cam pulley and the belt pulled to the side to get the thermostat cover off. The factory workshop manual states that there's enough room to do without taking the belt off but i did not find it easy and the seal is easy to get pinched. I have tried it a few times and i would not advise doing it that way. If the aux. belt tensioner bush is worn then it will need a new cast bracket which means you need to remove the AC compressor and the oil cooler to be un-bolted from the block ! Not as easy as it seems !
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  7. mystic.bertie
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    mystic.bertie Member

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    hi mate did you manage to change the thermostat successfully with loosening the left hand cam pulley? I still have not diagnosed the problem yet as im stuck on the viscous fan as per my other thread lol.

    also were you able to change the thermostat using this method and the carrier in the service position?

    many thanks
    Last edited: Oct 28, 2011
    #7
  8. adamss24
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    adamss24 Active Member

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    That's the way am doing it- done a few dozens that way ! You will nee the genuine locking tools to lock the crank and camshafts at TDC so they dont slpip...
    #8
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  9. mystic.bertie
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    mystic.bertie Member

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    oh i dont have genuine locking tools in fact the only kit available is the sealey one at £150, so it does not make it worth while, ill just leave the thermostat for now, its a real pain in the a$$. thanks for your help.

    now i know the price of the locking kit it makes it not worthwhile doing the timing belt myself either. when i done the a6 1.9tdi engine the locking tools were not that expensive.
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  10. mystic.bertie
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    mystic.bertie Member

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    hi mate sorry for the delay in updating my progress, as for as the repair to the power steering pump bracket goes, i have removed the bracket and i have a second hand one on its way.

    I ended up removing the service carrier so i now have great access to the front of the engine, with having this access can i replace the thermostat without removing the cam belt or is the situation still the same?

    many thanks
    rab
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  11. Turkster
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    Turkster Bro.Paul 2.5TDI Quattro Sport

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    it don't matter how much it gets sugar coated, the belt has got to come off or your in for a pig of a job, is changing the belt 20k early really such a bad thing?
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  12. mystic.bertie
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    mystic.bertie Member

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    well i know i will be criticsed for this but i cant afford to just splash out and do a timing belt, tensioners and water pump ie the works, i would rather fix it as cheaply as possible and i dont expect to have the car in another 20k. so i would rather do the minimum necessary to swap the thermostat. I have read the manual and its a major job changing the cambelts, there is a mechanic across the road from me was gonna help with removing the belt and changing the thermostat but im not sure if its possible without the pro[er locking kit, can it be done by using pins that fit the locking holes? If its so much hassle and cost i might just leave the thermostat as is.
    #12
  13. adamss24
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    adamss24 Active Member

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    You can buy the genuine v6 tdi locking tool kit from Philip Walker at PW Motorsport. Getting the belts changed might get you some money back or the car will be easier to sell than without the belts done !
    #13
  14. murran
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    murran Active Member

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    buy the kit, use it, then stick it on ebay. i bet youd get most of your money back.

    ive done many of these... the belt isnt easy. where abouts are you?
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  15. mystic.bertie
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    mystic.bertie Member

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    i done that with a locking kit for the 1.9 tdi, it only cost about £20, but the one for this engine i have seen is sealey and its £150 so i would be worried that nobody bought it as its not as common an engine.

    im in ayrshire scotland, there is a mechanic across the road from me, i was gonna get him to do the timing belt since it was so tricky but he cant really do it without the right locking kit.
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  16. Turkster
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    Turkster Bro.Paul 2.5TDI Quattro Sport

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    my money is on you leaving it as it is then, each man to his own pocket as they say,
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  17. mystic.bertie
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    mystic.bertie Member

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    quite possibly lol, if i knew i was keeping this car longer term i would do the timing belt etc for sure, the fuel econeomy is not as good as i hoped on this, i get 35mpg which i believe is average for this car, also im only on a temp contract at work, so as if the worst happens and i lose my job the car is first to go. I will then go back to running an old car on veg oil again lol.
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  18. scrag
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    scrag New Member

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    hi,i have the same problem.....thermostat.(and no money to spare!)
    what do you boys think about putting an inline thermostat in the top rad hose.....i read on another forum about using a thermostat from a renault 5 gt turbo..... 88 degree(not 82) someone suggested making fit inside the hose.....at the moment I have about 3/4s of my coolant rad blocked off ice road truckers style....ive replaced the temp sender and have 70/80 degrees showing on the dash during town driving,if i turn all the heating off i get up to 90 degrees on a run...(the second fan stays off)
    any thoughts?
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  19. mystic.bertie
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    mystic.bertie Member

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    i was about to do this, i was going to buy a renault 5 thermostat and somehow fit it inline, i cant see any reason why it wont work, there is a big thread on it on the rover 75 forum, thats where google took me with my research, if you have money to spare you can buy some nice metal oem looking inline thermostat from the states. This is better than having no thermostat at all and why pay all that money just to change a stupid thermostat, stupid stupid audi.

    oh i wrote my car off so problem solved lol
    Last edited: Jan 31, 2012
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  20. adamss24
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    adamss24 Active Member

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    Scrag, where about are you based mate ?
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  21. scrag
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    scrag New Member

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    im in winchester boss.....ive read some of your posts,and its obvious you know your stuff.......what do you think of the idea?
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  22. scrag
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    scrag New Member

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    oops sorry to hear your audi is finished...yeah it must be the same thread I've read..............but since buying the car last week and then finding out about the thermostat placement,I've read hundreds of pages trying to find a cheap cure!
    I've seen that meziere metal one...looks good and could be the way to go.
    the belts and pump and thermostat(contitech) were changed a little under 3 years ago...29000 miles on the thermostats goosed!
    #22
  23. adamss24
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    adamss24 Active Member

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    If you drive down to london, i could change the stat for you for about £100 labour + £20 for genuine thermostat and seal, i drive up and down the country often so i might be in your neck of woods sooner or later !
    #23
  24. scrag
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    scrag New Member

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    aye thanks for the offer.where in london are you?how long would the job take?
    #24
  25. adamss24
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    adamss24 Active Member

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    About 4-5 hours...
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  26. PAULF
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    PAULF Member

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    I'm also looking at a remote stat fix for my B5. I'm trying to get a top hose to chop up and try out a few ideas - the Rover boys seem to have had a good time with this one!
    The main thing is to get a small flow of coolant through as just sticking a thermostat inline may not work, as it needs some flow to give it enough heat to open. Ford or Landy stats and housings may be the way to go, with the bypass going back to the header tank.
    If I get a hose to chop and test, I'll post my results on here/on the B5 forum.
    #26
  27. scrag
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    scrag New Member

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    where abouts in london are you? i work twelve days on 2 days off but do have a bit of holiday to take...c
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  28. scrag
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    scrag New Member

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    hopefully my r5 gt thermostat arrives tomorrow,i will check if its got a pressure relief hole pre drilled or if not i will drill a 2mm hole....
    keep us informed of your findings on here mate and likewise....
    #28
  29. adamss24
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    adamss24 Active Member

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    Stop bodging it ! You most likely spend the money and maybe not work at all. Thermostats fail open for a reason so the engine does not overheat. Fit a new, genuine stat and you wont have problems again for years.
    #29
  30. scrag
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    scrag New Member

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    bodging......im afraid that started when the petrol tank split on me puch maxi.....i strapped an austin allegro washer bottle to the back rack and filled it full of 2 star(17pence worth) and piped it to the carb....i were only 11 haha.
    on a more serious note......
    the renault 5 gt turbo thermostat arrived and looks too big to simply slide inside the top rad hose..
    i phoned 3 garages within 30 mile radius,all claiming to specialise in german car repairs.
    2 said 5 hours labour quoting from autodata timescales....
    1 said 1.5 hours quoting from AUDI data......i presume this is because audi say the belt does not need to come off???????
    at £50 per hour and 20 for the thermostat it seems good enough for me not to buy a merrier inline thermostat and "bodge"it (i hate that word.......adapt it sounds so much better haha)
    adamss24 ......WHERE ARE YOU IN LONDON? i would prefer to give the work to you boss....but i aint coming round the m25 too far when i can go to h a s in fareham cos its about an hour from me.....
    i have asked you a few times where you are in london.....its a big place!
    cheers
    #30
  31. adamss24
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    adamss24 Active Member

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    ^^^Muswell Hill, North London mate... As i said, i cannot see the audi way of doing it in 1.5 hours, they are old cars and some bolts might be too tight or they seized + the housing is way too big to slide behind the belt. Trust me, i tried it and it does not work- the pulley needs to come off then the whole re-timing of the engine: vacuum pump off then the cover on the driver side, fit the locking tools, lock the crank, etc. All this take time, the front bumper alone takes about 15-20 min to remove !
    Last edited: Feb 3, 2012
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  32. Mike B
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    Mike B Member

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    This is right I have watched him and he is quick and no way could anyone change the stat in 1.5 hrs.I would also get the belts changed as 30k would justify the expense if there is cash ready and I was keeping the car.
    #32
  33. Turkster
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    Turkster Bro.Paul 2.5TDI Quattro Sport

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    1.5Hrs to do a cam belt change on a 2.5TDI, WTF whos on crack here? it could take that to get the front off and on again on its own!
    #33
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  34. adamss24
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    adamss24 Active Member

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    Paul, we were on about a thermostat change, one garage told the OP that they can do it in 1.5 hours estimate as per audi guidelines ! I cannot do-it in less than 4 and i have done dozens of these ! Here's the one on my allroad...i don't take pictures when i work, these were taken by friends whilst i was working !
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    #34
  35. spartacus 68
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    spartacus 68 Member

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    My thermostat has been playing up for around a year and a half. (B5 150PS) Sits flat until I have to tow a trailer, heaters blow luke-warm, etc. Still return 43mpg over full tank (500 miles). Timing belt and water-pump due this year too.
    How does the 1.9 TDI timing belt job (B6 130PS) compare? [​IMG]
    #35
  36. scrag
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    scrag New Member

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    ok i fitted the renault 5/volvo 340 thermostat into the top radiator hose.......about 30mm into the hose from where it joins the engine.....89 degrees showing on dash.....
    260 miles later and no problems.....except for one i have caused when i took apart the i think intercooler alloy part that has a valve of some description.....
    when in park and i rev her up.....on the way down the revs seem to stutter a little around the 1200rpm mark...but within a second they drop to 800ish and idle is perfect.a thin black vacuum pipe came from somewhere under the header tank....i found where i think it came from.(a two port small part with electric connector going in on top.....and popped it back in.....no change
    any ideas n what i have disturbed?????

    adamss24 i take on board your concerns about this bodge,i will keep a close eye on my work... and i thank you for your time mate.....if you are free saturday 18th i would drive up and gladly pay you a couple of hours at your hourly rate for you to have a look around her and plug her in to vcds,and give me your honest opinion..
    i do have a bit of holiday left to take if one week day would be better for you?
    Last edited by a moderator: Feb 7, 2012
    #36
  37. scrag
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    scrag New Member

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    o dear sorry quattro james......so its ok for turkster to insinuate I'm a crack taker,albeit tongue in cheek....the boy needs to read posts properly.....but i can't tell him that or mention turkeys darkest export huh????never mind eh?

    too add to my post,it were the throttle body that i took off for access to the rad hose.......it were gunned up wi oily muck so i cleaned that out....but maybe not good enough and i might have pushed some crud somewhere it shouldn't be????in the butterfly valve area????
    anyhow ile take it off again tomorrow and clean it all up.....see if that cures it....
    #37
  38. quattrojames
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    quattrojames Moderator Staff Member Moderator

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    My interpretation of Turksters post was that the garage were 'on crack'... not you. So don't take all you read so personally.

    It was the garage quoting 1.5 hours, not you I believe?

    He did indeed misread your post, not the first person and not the last to misread a forum post I'm sure.

    I edited your post as it contained a personal insult.
    #38
  39. scrag
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    scrag New Member

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    ok...now i see it that way as well so i apologise.
    #39
  40. PAULF
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    PAULF Member

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    Well done with the Renault fix Scrag. I'll let you know how I get on with my efforts,although it's low down my list at the moment.
    I would prefer to have a housing solution of some sort, as it seems wrong to just fit it into the hose - and,yes,I know it is supposed to be like that!
    #40

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