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Problems starting since new DMF

Discussion in 'Audi S4/A4/A4 Cab (B7 Chassis)' started by A4mikep, Aug 13, 2014.

  1. A4mikep
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    A4mikep New Member

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    [Aug 13, 2014]
    Hi All,

    New to the forum, please bear with me here as ill try to fit as much info in as i can, im looking for advice as now im stuck with my car in garage looking at in excess of more than a weeks labour and numerous new parts.

    Audi A4 S-line 07

    Problem - I had my DMF changed at a local garage over a year ago, initially they thought it could of been an injector so they were sent of for inspection with no avail they moved on to the DMF, once changed everything was fine for a while during the winter months. Then when the weather started to warm up the car started having problems starting when left overnight, it takes AT LEAST 20 seconds to turn over, cranking seems fine just takes ages to actually turn over. This has got gradually worse to the point that if the car is left for over 2 hours it does this every time. The car runs fine once its started and any time within the 2 hours turns over like a normal car should.
    I took the car back to garage, as the car is not throwing any codes, they advised me to get an auto electrician to see if he could find anything (the garage thought it could be the crank sensor).
    So i took my car to a different garage near my work that specializes in auto tuning and remapping to ask if he dealt with electrics (he didnt), however he ran the vag-com for free to see if he could find anything, nothing showed up apart from the car idling a bit high at 8700.
    He then put me on to his business partner who owns a garage across the road i find him quite an honest guy he advised me that he doesn't think its a problem with the electrics and thinks its a problem with fuel somewhere as fuel seems to be draining back in the car with not enough to turn over.

    He pressure tested all the fuel lines all seemed fine, but proceeded with my authorization to change the fuel pump sensor and the fuel filter, checked the fuel pump, car seemed to run smoother but the problem persisted.

    Then moving on to other parts which he thought could be the answer to the problem changed the crank sensor, engine coolant sensor, then sent the injectors of to be tested a new injector came when they sent the rest back obviously there was a problem with one. we thought this could be it however when starting the car the next day the same problem was there.

    Then checked the timing out and found the timing was out slightly, hes had the front end of and with help from a friend who works at a volks garage using his tools to align everything perfectly, and tried a new starter motor (teeth are *******), he said the car seemed to run with more power after this fault was found however the car still would not start properly

    Today he has had an auto electrician out to test the flywheel, apparently the wrong flywheel could of been fitted as there are a few to use, electrician said it all checked out fine

    The questions are; has anybody had this starting problem before and found out what the issue is? Or could anybody advise me what this could be?

    apologies for the long post i know its a lot if information to take in, just trying to get all the key points across.

    Many thanks in advance
    Mike
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  3. Giosabcsl
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    Giosabcsl Active Member

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    [Aug 13, 2014]
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  4. joinerman
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    joinerman Well-Known Member

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    [Aug 13, 2014]
    Glow plugs !!!
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  5. A4mikep
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    A4mikep New Member

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    [Aug 14, 2014]
    Hi Giosabcsl,

    Thanks for the reply, this doesn't seem to be the case with mine, my problem is in the morning or when the car is sat for while (2 or more hours) then it take ages to turn over like i said about 20 seconds. Once the car has started up its fine, it runs fine and will start perfectly every time unless i leave it again.

    Mechanic now saying he is baffled by it, hes tried everything he thinks it could be and advised me to take it to Audi to see if they can shed any light on the situation, i really don't want to do this i know it will cost a fortune!
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  6. A4mikep
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    A4mikep New Member

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    [Aug 14, 2014]
    Hi Joinerman,

    Glow plugs have been checked, battery been checked, im sure the mechanic said he tried a more powerful battery as well to see if it would turn over quicker.
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  7. martynash
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    martynash Ask ....I don't Bite....much!

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    [Aug 17, 2014]
    Check the amperage being drawn by the starter (need an inductive ammeter for this) this will prove starter OK.
    In VCDS check for rpm reading while cranking. This will test crank sensor and give you a figure (speed rpm) compare with spec. If not correct, could be as simple as and earthing fault.
    Also in VCDS you should be able to see the fuel pressure (in BAR 1 bar=14.2 psi) check to see if this remains in tolerance during cranking. You may need to attach a pressure gauge to the fuel rail as another test.

    I sincerely hope your car is not idling at 8700 rpm as you state. If it is, turn it off immediately :eek:

    Probably be helpful to tell us if its petrol or oil fired and even what engine might be under the bonnet size/cc and code. and also whether manual or auto.

    Find a Tech who traces the fault and doesn't just keep changing things hoping to cure the fault without finding/knowing what the issue is.

    Regards

    Marty

    PS: - MODS where did all the toys go on the site????o_O
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  8. martynash
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    martynash Ask ....I don't Bite....much!

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    [Aug 17, 2014]
    Re-think

    If you had the dual mass replaced they removed the gearbox I hope! This means all the earth's would be removed. If they are not replaced or not tightened sufficiently this will create the slow cranking you describe. Cost nothing to check/tighten. Repair manual will show locations of all earth's

    Regards

    Marty :)
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  9. theo289
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    theo289 Member

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    [Aug 19, 2014]
    is there any update on this as i have exactly the same issue on mine
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