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

A3 2001 Limp mode and excessive fuel consumption.

Discussion in 'A3/S3 Forum (8L Chassis)' started by Sniper210010, Jan 15, 2013.

  1. Sniper210010
    Offline

    Sniper210010 New Member

    Joined:
    Jan 15, 2013
    Messages:
    17
    Likes Received:
    0
    Hi all,

    I hope you can help :(

    I have just bough a 2001 a3 1.9 TDI, the issue i have is that the car goes into Limp mode at around 3000 RPM reguarly and i cant figure out why? i have also used almost a quater of a tank of fuel and i have only done 40 miles on very sensible driving!

    I have previous tickets for work done and the Mass airflow was replaced in 2005 due to "Poor Performance"??

    I had a friend look at it and he found some small pipes (part of the Vac in/out) had holes in them and these were replaced but the problem persists :/

    When i started the car this morning it really struggled (Its cold and been snowing) and snorted a big puff of white smoke when it did start. i had read somewhere that the turbo may be leaking?

    I have a code reader on its way so should be here this week for more info.

    Can anyone shed any light on this in the meantime??
    #1
  2. Paul_TDi
    Offline

    Paul_TDi Member

    Joined:
    Jul 1, 2010
    Messages:
    216
    Likes Received:
    0
    Limp mode will usually produce a fault code along the lines of boost deviation which usually means either leaking vac lines (have you replaced them all?) dodgy N75 valve or choked up/dieing turbo.

    Boost leaks may be something else to look into before replacing the turbo, as the intercooler pipe work have joints prone to leaking. (assuming to have a PD130)
    #2
  3. Sniper210010
    Offline

    Sniper210010 New Member

    Joined:
    Jan 15, 2013
    Messages:
    17
    Likes Received:
    0
    Thanks for the quick response Paul_TDi

    Not all of the Vac lines have been replaced yet, i will certainly do that - Oh good please do let it be the turbo :/

    Would any of the issues you have listed above contribute to poor fuel economy then?

    The car is a 110 SE <---- im not sure if that helps.

    If i may ask.....what would you check first as process of elimination and how would i know whats faulty or not?

    I have a Diagnostic tool on order so hopefully that will shed some light on this in a couple of days.

    Aside from a new turbo are the other parts expensive do you know? fitting is not an issue as i have a mechanic on hand for the labour :D

    Many thanks again!
    #3
  4. Sniper210010
    Offline

    Sniper210010 New Member

    Joined:
    Jan 15, 2013
    Messages:
    17
    Likes Received:
    0
    hey guys,

    got these codes when running a diag scan....

    17965
    19561
    17664
    18062
    18058

    Any help is much appreciated.
    #4
  5. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,726
    Likes Received:
    20
    Have a look here and post up the result :)
    Category:Fault Codes - Ross-Tech Wiki

    <tuffty/>
    #5
  6. Paul_TDi
    Offline

    Paul_TDi Member

    Joined:
    Jul 1, 2010
    Messages:
    216
    Likes Received:
    0
    Well your first code is what I suspected, unfortunately I don't know what the others mean.

    the 110's had a simpler intercooler pipework connectors so less likely to be a boost leak from the joints.

    The N75 valve is fairly inexpensive about 30 quid tops from dealers.

    Naturally do the cheapest things first basically, vac lines, N75 valve and the N239 valve was mentioned in those codes to.

    You could also attempt cleaning the turbo, a lot of people are working the actuator loose with Mr. Muscle oven cleaner, see here
    #6
  7. Sniper210010
    Offline

    Sniper210010 New Member

    Joined:
    Jan 15, 2013
    Messages:
    17
    Likes Received:
    0
    So a mechanic friend told be to clear the codes and drive around until it hits limp mode again, then do another check:

    Here's what I got....

    17965 - Suspect N75 valve, have just been to parts specialist to pick up a new one, its also worth noting that the mass air flow sensor was replaced by Audi in 2005. If the vac lines are the culprit would that explain the 17965 error code? and mean that I might not even need a new N75?

    18062 - Please check DTC memory of instrument cluster <---- I don't know what this is?

    Is it safe to say that the turbo almost defiantly is NOT at fault??

    Again thanks for the great info!
    #7
  8. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,726
    Likes Received:
    20
    17965/P1557/005463 - Ross-Tech Wiki

    17965/P1557/005463 - Charge Pressure Control: Positive Deviation

    VNT vanes in the turbo are blocked by the sounds... common problem...

    <tuffty/>
    #8
  9. Sniper210010
    Offline

    Sniper210010 New Member

    Joined:
    Jan 15, 2013
    Messages:
    17
    Likes Received:
    0
    would that cause the car to use excessive fuel then?
    #9
  10. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,726
    Likes Received:
    20
    From what I understand yes...

    <tuffty/>
    #10
  11. <tuffty/>
    Offline

    <tuffty/> Badger 5 Edition Staff Member Moderator

    Joined:
    Sep 14, 2008
    Messages:
    15,726
    Likes Received:
    20
    #11
  12. Sniper210010
    Offline

    Sniper210010 New Member

    Joined:
    Jan 15, 2013
    Messages:
    17
    Likes Received:
    0
    So I have replaced the vac lines and the n75.... Still getting limp mode with the 1 code: 17965 :/

    Something else just happened an it's the first time it's done it. Started the car from cold pretty much and had it running while i de-snowed (been snowing here). About a mile down the road it completely lost power after a sudden shudder and was billowing white smoke from the exhaust..... Pulled up and no lights came on, did an immediate code check with the U281 but no codes appeared. Drive the car 10 mins home and limp mode kicked in.... That's when I got the code 1965?

    So potential boost leak? Or turbo issue?

    Dont even know where to start with what just happened :(

    Again still thankfull of any advice :)
    #12
  13. Cobra88
    Offline

    Cobra88 Member

    Joined:
    Sep 20, 2011
    Messages:
    489
    Likes Received:
    3
    Mine has done this a couple of times and it turned out to be my Glowplugs.
    just not heating the charge enough in the cold weather and basically blowing out the source of ignition.

    Dont use a lot of throttle when the engine is cold and it should be fine (and get someone to check that all the glowplugs are working and the heaters near the Vac Pump (3 glowplug like items) that heat the water on initial start)

    Regards
    Rick
    #13

Share This Page