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Loss of power lumpy and smoking A6 2.5 TDI

Discussion in 'Diesel forum' started by Flatdog, Apr 21, 2009.

  1. Flatdog
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    Flatdog New Member

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    Hi Guys
    Can anyone offer me advice please. 2000 130,000 miles. Car running like a dream until yesterday I started her up and she was runny lumpy, then noticed smoke (White/hint of blue) Lost a lot of power. Car shuddering a bit on tickover. Felt all the world like a vacuum hose was leaking (experienced on previous cars) Checked what hoses i could and replaced a couple that looked a bit dodgy. Made no difference. I plugged in a VAgCom thingy I had bought on fleabay about a year ago. No faults. Looked through the forum and just managed to confuse myself with all the advice.
    Doesnt seem to be excessive pressure when I open the oil filler after a run.
    Smokes like hell when i accelerate up hill or even maintaining speed. No smoke on deceleration.
    Could it be the EGR? Is it worth cleaning it or getting a new one?
    How would I diagnose that?
    Could it be the Turbo? How would I diagnose that?
    Could it be anything else?
    Anyone in East Lothian or Edinburgh sort of area with a proper VagCom?
    Any advice appreciated. Thanks for looking.
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  2. etronic
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    etronic TDI

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    Check you intake hoses/clamps. Also this may be turbo failure. Have you had you crankcase breather replaced? These are main scenarios but full diagnostics would tell more(no just errors check).
    #2
  3. Flatdog
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    Flatdog New Member

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    Thanks. I will check all the intake stuff, I looked at the air filter but I just replaced that a couple of months ago and it is clean as a whistle. I used an unregistered vagcom so i presume it has limited functionality. I am reluctant to take it to the dealers as I fear they will say the turbo (whether it is or not) and I suppose I am looking for a real diagnosis before I go there. I once got stung with a new water pump on another car when it turned out that the radiator cap was all that was wrong in the first place. The belt is due to be changed soon, is it possible that the belt has slipped? What about N75 and stuff like that?
    Hoping in vain that it is not expensive, but such is life.
    #3
  4. etronic
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    etronic TDI

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    N75 wouldn't cause white smoke.

    Slipped belt is possible as beginning of injection will be retarded and white smoke will appear as effect.

    Best thing is to find someone who can diagnose your car properly.
    #4
  5. fjtwelve
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    fjtwelve Moderator Staff Member Moderator

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    White smoke is crankcase breather filter blocked
    Black smoke is N75 valve (pressure relief valve on turbo)
    EGR generally clogs up slowly, sudden power loss unlikely to be this, but giving it a thorough clean is always a good idea
    Head gasket? Has it used oil or water?
    Unfortunately your engine is in the right age bracket for dodgy cams and followers. If you can't diagnose the fault electronically i would say the belts get checked then lift the cam covers.
    The fuel pump is a complicated beast and can fail, if you haven't found it after the above checks then there are specialists around who can check and repair - new ones are a tad expensive.
    Best nearest independent I know to you is Star Performance at Dysart in Fife but suspect someone can find you a closer one.
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  6. Flatdog
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    Flatdog New Member

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    Thanks Guys, went to a garage run by 2 ex Audi Edinburgh mechanics today. Nothing showing on diagnostic. They reckon the car runs slightly better with the MAF unplugged so that is probably stuffed. Said they would have to take rockers off and check compression? They mentioned a similar but worse problem with another 2.5 TDI was a broken camshaft. So you may be spot on fjtwelve.Taking it back tomorrow and leaving it with them for a good look. Will keep you posted.
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  7. fjtwelve
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    fjtwelve Moderator Staff Member Moderator

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    Exchange MAF should cost you around £75 and its a DIY job to fit. Could well be gone but when i have had a MAF fail it has not given the symptoms you describe. Would have thought a bust cam would make quite a lot of noise. Anyway if they are checking compression they can look at all the valve gear too. They can have a more thorough check of all the hoses too if its up on a ramp eg the intercooler hose running around the bottom of the front of the engine which is bloody awkward to get at.
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  8. Flatdog
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    Flatdog New Member

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    O well!! Cams, etc all stuffed. Quote £1400 before they find any more damage. That includes new belts. They don't know why it happened though. Slipped belt? Is that usual or possible?
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  9. quattrojames
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    quattrojames Moderator Staff Member Moderator

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    The belt skipped on mine because the tensioner pulley disintegrated so it is quite possible for the belts to slip/skip - however it should be obvious if this had happened. They should be able to tell from the positioning of the cam pulleys if the belt has skipped.

    Hope you get it sorted and they don't find too much else wrong.
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  10. Flatdog
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    Flatdog New Member

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    Just going through the service history. I bought the car Feb 08. Invoice from Stirling Audi dated Dec 07 for £1491 for replacing cams. The car has done 22,000 miles since then, driven by me. I am by no means a boy racer or hard on the car and has mostly been motorway at circa 70 mph. I have changed the oil twice in the 22k with fully synthetic Miller oil. Why should the cams go again? So soon? Do you think I have any hope of some sort of recompense from Audi? Their warranty says 3 months or 3k. Anyone else this unlucky?
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  11. etronic
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    etronic TDI

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    Sorry to hear that mate.

    Slipped belts are not common fault in these engines unless they are heavily overrun. Maybe tensioner failed...

    Another "done" V6 TDI owner... Shame on AUDI...
    #11
  12. quattrojames
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    quattrojames Moderator Staff Member Moderator

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    On my original engine the tensioner pulley disintegrated and the belt skipped four teeth wrecking all the cam and some of the valves. Bought a reconditioned engine which was in 6 days before the bolt holding the idler pulley on broke and the same thing happened again. Oh the irony ......

    Got to be worth talking to Stirling Audi, I know it is well out of warranty, but if you can establish why the cams have gone again I would give them some stick. It certainly shouldn't have happened again after 22k :slapped:
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  13. Flatdog
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    Flatdog New Member

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    Absolutely. Will certainly be calling them in the morning. It shouldn't happen again so quickly. Sorry to hear about your probs. I love the car, I had Audi 100s many years ago, loved them too, but I fear paying all that cash and it happening again in another 22k.
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  14. quattrojames
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    quattrojames Moderator Staff Member Moderator

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    How did you get on?
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  15. Flatdog
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    Flatdog New Member

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    Spoke to the independant and also Audi Stirling, I have to call and speak to I presume the Service Manager on Tues at Stirling Audi. Both agreed that the cams should not go so quickly. Back of the invoice from Audi states warranty for 3 months or 3k but independant state that parts should be at least 2 years. Will keep you posted.
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  16. fjtwelve
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    fjtwelve Moderator Staff Member Moderator

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    You have my heartfelt sympathy. On the upside it looks as if you may pay considerably less than i did.
    I don't know if you've read my thread but the cams on mine had to be replaced twice, but the big difference is that the first time the job was done by a company that turned out to to be a bunch of cowboys who have a reputation for not doing the work they said they had and now gone broke to trade under another name so i don't believe they ever replaced them. The first job the car never felt quite the same, the second job very quickly brought the car back to its old self.
    In your case the parts and work was supplied by an Audi dealer. I cannot believe that a set of genuine Audi cams has failed in 22000 miles. Even the defective batch that has caused the original problem lasted 100k. If you get the run around go to trading standards with all the info.
    Most definitely do not just assume the cams are the only problem. You must get them to check around the rest of the engine. If the cams are fooked the followers almost certainly will be too. Also check valves and valve stem seals haven't been damaged. Oil pump should be checked - all that metal that wore off went somewhere. If the front of the engine is all in bits check the water pump and all the idler pulleys, cheaper to replace now than pay the labour for getting the front of the engine off again later.
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  17. Flatdog
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    Flatdog New Member

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    Sorry to hear of your troubles with cams. Everyone I speak to says they have never heard of cams going like this. Anyway, car sent to Audi Stirling and I will await their judgement.
    I cannot praise enough the helpful attitude of Autohaus Edinburgh http://autohausedinburgh.co.uk/default.aspx and will definately be using them in future.
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  18. Flatdog
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    Flatdog New Member

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    RESULT. I am over the moon, Stirling Audi repairing my A6 under warranty. Also discovered that the belts and water pump etc. had been done same time as last cam repair so all is well with me. Getting the car back on Tues so cant wait. Thanks for all your ears and support and I hope you all have the same luck I have just had.
    :rockwoot:
    #18
  19. quattrojames
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    quattrojames Moderator Staff Member Moderator

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    Nice! I am glad to hear one 2.5TDi owner walks away from engine failure quids in for once! :)
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  20. fjtwelve
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    fjtwelve Moderator Staff Member Moderator

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    I couldn't possibly comment, can't decide if i'm pleased or envious, just glad you're back on the road. Good for Stirling Audi. I would be very interested to know why the cams went after 22000, can you find out.
    #20

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