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A6 Avant 2.5tdi quattro tiptronic - new pump = bad MPG and power

Discussion in 'Diesel forum' started by JohnG60, Dec 28, 2010.

  1. JohnG60
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    JohnG60 New Member

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    [Dec 28, 2010]
    Hi there

    Just a quick question - hope I'm posting in the right place

    We have a 1999 A6 Avant 2.5tdi Quattro tiptronic which we've had for the past 7 years. Fontains did a cambelt change and full service 5,000 mile ago. about 1,000 miles ago the car just wasn't right, down on power etc, then 4 weeks ago it just cut out dead when I was accelerating. Got it into TC Garage in Sussex and after a week looking around (no error codes apparently) they announced it was the high pressure pump. We needed the car over Christmas so could not afford to wait for a recon unit so told TC's to fit a new one (not cheap! )

    Anyway we were told the car was ready at 11.00 Christmas eve so went down to pick it up but it's not right. Did a couple of 60 mile dual carriageway runs the last 4 days and whereas we would normally get high 30's to low 40's mpg on that run we are struggling to get 31mpg - around town I'm lucky to get 20 mpg. The power is down as well - previously acceleration from 60 - 90 was a good solid push in the back, now it's gutless - torque feels really low and the tiptronic keeps trying to change down a gear to get the power on - it never used to do that unless I floored it. Also it's not starting as easily as it used to

    I suspect they rushed the job and didn't time the pump properly - How would I find out if the pump timing is out and how much of a job is it to get it done properly ? Bearing in mind we just paid a lot for investigation, new pump and fitting, I'm thinking of going to GCS engineering in Horsham, Sussex, has anyone tried them before ?

    The car has 130k on the clock - it runs relatively cool but always has done.

    Any suggestions would be very welcome
    Last edited: Dec 28, 2010
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  3. adamss24
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    adamss24 Well-Known Member

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    [Dec 28, 2010]
    As you said, the pump might not be timed properly... If you could drive to N. London i could time the pump for you for a few beers ! Regards, Chris- 077 899 12128.
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  4. JohnG60
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    JohnG60 New Member

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    [Dec 28, 2010]

    Hi Chris

    Many thanks - I might take you up on that if I can get it running

    Just went out to take it down to the garage to fill up -wouldn't start. cranks but doesn't even try to fire. dead as a Dodo.

    TC Garage in Sussex - don't touch them ! car went in last July as the Air con wasn't working - they diagnosed a leak on the compressor which the said they could fix, also said they needed to change the A/C cooling radiator. bill was for over £650 and it worked for one day ! I wasn't prepared to pay them another £600 for a new compressor so currently still no A/C - will get it done in March.

    Had little choice on garage location for this fuel pump replacement - cost over £1,800 for diagnosis time, new pump and fitting (I got the new pump via a friend at trade) and it's worked for 4 days ! They will never touch one of my cars again.


    Bunch of cowboys
    Last edited: Dec 28, 2010
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  5. adamss24
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    adamss24 Well-Known Member

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    [Dec 28, 2010]
    For 1800 quid i would have bought a new car mate ! Most i've paid was 600 + VAT for a fully rebuilt pump from Dieselbob. You could have fuel draining back to the tank if the pipes were not tightened properly and/or the pump is waay off the spec- not timed properly ! Did they mark and pray ?! The easy way to start the V6 is by tow start-it if its MANUAL ! Saves a load of the starter and battery... Yours is an auto so it wont work...U can use easy start/brake cleaner but its easy to hydrolock the engine if to much is squirted into the intake...If you cannot get it started i might be able to came and time-it on your driveway but i would charge a little extra for fuel...Let me know where you standing but i will have time from thursday on, quite busy with changing a alternator on a v6 and i also have a 2.0Tdi in for a service and brakes all round... Regards, Chris- 077 899 12128.
    Last edited: Dec 28, 2010
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  6. JohnG60
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    JohnG60 New Member

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    [Dec 28, 2010]
    Thanks Chris

    Let me see if I can get the thing going tomorrow and then take it from there
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  7. JohnG60
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    JohnG60 New Member

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    [Dec 31, 2010]
    Just to say thank you to Chris

    Drove the car up yesterday and Chris re-timed the pump for me - took less than one hour, my local Audi specialist had quoted 3 hours plus a diagnostic to do the same job. On the 80 mile drive back to East Grinstead the car was pulling cleanly again, fuel consumption for the trip back came in at 38mpg and it started on the first turn this morning. happy days :)

    Chris - you certainly know your Audi's - I'll contact you in the new year to get that gearbox oil changed. Again many thanks

    John
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  8. adamss24
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    adamss24 Well-Known Member

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    [Dec 31, 2010]
    It was nice to talk to you John, please get in touch when you have time to spare for changing that gearbox oil + strainer (oil filter to you and me !)... Thanks again for the recomendations and beer monery ! Happy new year folks !
    Chris.
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  9. HerefordQuattro
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    HerefordQuattro Member

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    [Jan 3, 2011]
    Love it when the forums work for each other, wish Chris lived a bit nearer to me for advice etc,

    out of interest was the timing massively out?
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  10. JohnG60
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    JohnG60 New Member

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    [Jan 4, 2011]
    Hi there

    No not massively out I don't think - although far enough retarded that Chris had to physically adjust the pump as it was outside the compensation limits. Chris would be able to clarify exactly how much it was out.

    I'm still getting air in somewhere though. yesterday it fired then died on a cold start and I had to crank for quite a while - TC's had identified air getting in somewhere and changed the washer seals on the injector return pipes but obviously that wasn't the problem.

    Apart from that it's running well at the moment
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  11. adamss24
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    adamss24 Well-Known Member

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    [Jan 4, 2011]
    If you have a 17mm spanner then i would just try to tighten the hard likes a touch but me money are on the platic tee (thermostatic valve on the fuel filter). I had a few v6 tdi with hard starts due to the said valve but you said the fuel filter has not been disturbed wich is odd especially if the hard starts started since the main pump has been replaced ! Out of curiosity, did the garage messed about with the lift/priming pump inside the tank ? The plastic is brittle and there it could be the air ingress... As i said i would check every union that has been disturbed on the pump/fuel filter and make shure they torqued properly !
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  12. JohnG60
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    JohnG60 New Member

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    [Jan 4, 2011]
    Hi Chris

    The garage originally thought the problem was the lift/priming pump so they were messing around at the rear for 3 days until they figured it was working and it must be the injection pump - so nothing can be ruled out as to what they've done !

    I've just received my set of Elsawin CD's for the car today and am currently loading those up which hopefully will help me find my way around a bit better - 25 years ago I thought my Alfa GTV6 was a complicated car ! little did I know :)

    I'll go through the checks/steps you mentioned and see how it goes. On a warm start it goes first turn and apart from yesterday has started from cold with no problems either.

    I'll keep you posted, and thanks again
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  13. swarcup
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    swarcup Well-Known Member

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    [Jan 5, 2011]
    Chris is amazing with the 2.5 v6. I travelled from east yorkshire down to london and he did my cambelt thermostat and all the trimmings including a pump retime. Very nice guy dont be afraid to go down and see him. I certainly wont think twice about it
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  14. adamss24
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    adamss24 Well-Known Member

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    [Jan 5, 2011]
    Thanks a lot chaps for the kind words... Jon, i would check the lift pump in the tank- remove the black round pannel and check the jubilee clips are tight. Also you can see if you park the car nose down on a slope- if it starts in the morning without sputtering then the fuel runs back to the tank. I will also replace the leak-off pipes from the injectors to the pump. Dealer also sell a non return valve wich fits inline to the fuel line and it wont let the diesel drain back in the tank. i would also buy a thermostatic plastic valve and genuine vw or Hengst filter from Euro Car Parts. Its a minor thing wich might have been overlooked but it's frustrating till you get to find the culprit !
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