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Lumpy Idle - coolant sensor?

Discussion in 'A3/S3 Forum (8L Chassis)' started by recomdos, Sep 13, 2005.

  1. recomdos

    recomdos Member

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    Hello /ubbthreads/images/graemlins/smile.gif

    I ran a vagcom check not long before going to Oz and having got back I remembered there was an error with the engine coolant sensor.

    So I checked it over again the other night and it's there with a lambda sensor error too.

    Having not really seen any noticeable signs, I was thankful for the vagcom, just to be aware!

    This morning though, the car decided to be a bit weird. Tick over would sporadically rise to approx 2krpm, and the 'range' on the dis was going nuts!

    I know others have had similar problems and I was thinking just last week she seems to be drinking a little bit more thristier.

    So to get to the point, how easy is it to replace these parts? I was thinking the lambda may be best left to the garage when I can get it booked in, but how bout the engine coolant sensor? Any ideas on prices, and fitting? Is there any how to guides out there either?

    Lots to be asking there fellas and I appreciate any help at all!

    I can post fault codes later if it helps?

    Cheers,

    Rob /ubbthreads/images/graemlins/laugh.gif

    ...oh there was also a fault saying adaptation limit surpassed? (IIRC :S)
     
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  3. RichA3Turbo

    RichA3Turbo ...Watching you!
    Staff Member Moderator

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    [ QUOTE ]
    ...oh there was also a fault saying adaptation limit surpassed? (IIRC :S)

    [/ QUOTE ]

    Almost certainly the Lambda then! This means the fuel micture is not being reported correctly.

    Rich
     
  4. marctwo

    marctwo Member

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    I had the coolant sensor fault on mine using VAG-com. Didn't notice any running issues but took it into the stealers and they replaced the sensor under warranty. According to a friend with an Octavia vRS, there are 2 kinds of sensor, the old type and the new type. The old type (that I had) was prone to issues). I now have the new type.
     
  5. imported_gek

    imported_gek Guest

    I replaced my coolant sensor last weekend.
    Got the sensor off vagparts, plus a new o ring for just over £20.
    Had it fitted within 10 mins, it really is that easy.
    Instructions can be found here
     
  6. recomdos

    recomdos Member

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    [ QUOTE ]
    I replaced my coolant sensor last weekend.
    Got the sensor off vagparts, plus a new o ring for just over £20.
    Had it fitted within 10 mins, it really is that easy.
    Instructions can be found here

    [/ QUOTE ]

    Nice one Gek! that's at least some news I was kind of hoping for! /ubbthreads/images/graemlins/smile.gif

    as for the lambda, then I'll just have to get it done. is it just one sensor on the A3 T (98 model or two? :S) I'm tempted to buy the part and let the garage fit it. Some investigation to be doing me thinks! /ubbthreads/images/graemlins/book.gif

    here are the errors it was throwing back:

    Address 01 -------------------------------------------------------
    Controller: 06A 906 018 AQ
    Component: 1.8L R4/5VT MOTR HS D03
    Coding: 04000
    Shop #: WSC 06313
    2 Faults Found:
    16500 - Engine Coolant Temp. Sensor (G62): Implausible Signal
    P0116 - 35-10 - - - Intermittent
    16518 - Oxygen (Lambda) Sensor B1 S1: No Activity
    P0134 - 35-10 - - - Intermittent
    Readiness: N/A

    Address 35 -------------------------------------------------------
    Controller: 8L0 862 257 G
    Component: ZV-Pumpe, DWA, Funk D05
    Coding: 13130
    Shop #: WSC 06313
    2 Faults Found:
    00955 - Key 1
    09-00 - Adaptation Limit Surpassed
    00956 - Key 2
    09-00 - Adaptation Limit Surpassed

    Thanks /ubbthreads/images/graemlins/smile.gif
     
  7. HTC

    HTC Active Member

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    The coolant sensor is fooked or the wiring is duff. Most likey the sensor tho.

    As for the lamdba error, it does sound like its probably dirty or duff.

    You can check the lambda operation by looking at reading block display group 07 after the coolant temp has reached 80 degrees.

    Display zone 2 shows the voltage of the lambda probe signal.

    ‒ If the probe voltage fluctuates very slowly, then the the lambda probe heating is prob not working.
    ‒ If the display shows a constant lambda probe voltage reading of 0.45...0.50 V, this means there is an prob with the wiring.
    ‒ If the display shows a constant voltage reading of 0.0...+0.3 V (mixture too lean), this means that the lambda control has reached the control stop in the "enrich" direction, but the lambda probe is still registering "Mixture too lean".
    ‒ If the display shows a constant voltage reading of 0.7...1.0 V (mixture too rich), this means that the lambda control has reached the control stop in the "lean" direction, but the lambda probe is still registering "Mixture too rich".

    If everything looks cool, then you can check the lambda learned values, which is the ECU's learning ability to cope with different engines and provide the correct injection times to get the lambda vale of 1.

    Look at display group 08. Zones 2 and three are the learned values. Zone 2 is the value at idle and zone 3 is the value for across the rest of the rev range (when driving).

    Zone 2 shouldn't be more than +/- 10% and zone 3 shouldn't be more than +/- 8%

    I won't go too much into the causes as it can be down to air leaks, dodgy injectors, bad maf or incorrectly functioning fuel pump relay amongst others.

    I think you should swap or clean the probe and then see how you go. Your car should have two sensors and I think S1 is the one before the cat.

    Hope that helps a tad.
     
  8. recomdos

    recomdos Member

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    wow - very helpful HTC.

    Thanks a bunch man!

    Swapping/cleaning the probe - how difficult is this? I heard from someone else that a special tool is required /ubbthreads/images/graemlins/frown.gif

    Cheers /ubbthreads/images/graemlins/laugh.gif
     
  9. SimonPoole

    SimonPoole Member

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    I have a similar problem at the moment, my local stealers said that no fault codes were showing, but there was a value which was outsided normal spec. They want to try a new airflow meter, although I have serious doubts about this being the cause. The car is now booked in for Tuesday for a more in depth diagnosis, looking at the new throttle body which they fitted in February. Like I say, no fault codes at the moment, but an idle which rises and falls and a black exhaust.
     
  10. HTC

    HTC Active Member

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    Rob, swap the temp sender first and then clear the codes. Then take it for a drive and then stop and check the fault codes again. Basically start with the easy stuff first.

    I'll respond to your PM here as its good reading for other people.

    If the lambda codes return, then look at measuring block 07 as described above, then let us know the results of that before heading onto other stuff. But I've just realised that I haven't ask for your engine code. If yours is the throttle cable AGU engine then you only have one lambda sensor. If yours is a different engine code then the proceedure above won't be correct.

    To remove the sensor you'll just need a spanner, but it may be pretty subborn. Sometime a hot exhaust pipe can help. There is one connector under a plastic cover on the underside of the car near the cat. You'll see it no probs.

    A new probe for an AGU engine is £85.70 inc vat.
     
  11. recomdos

    recomdos Member

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    I /ubbthreads/images/graemlins/1luvu.gif you HTC! /ubbthreads/images/graemlins/laugh.gif

    The coolant sensor arrived today, so fitted it this afternoon. At first it still reported faults /ubbthreads/images/graemlins/frown.gif but after manually looking in the fault blocks i deleted them, ran specific scans - and hey presto all gone!

    Asides from a double check, it was so obvious whilst driving - so much smoother through the rev range, and no jerkyness! /ubbthreads/images/graemlins/laugh.gif

    Thanks again mate - all fixed for under £20. /ubbthreads/images/graemlins/beerchug.gif

    Rob /ubbthreads/images/graemlins/smile.gif
     
  12. HTC

    HTC Active Member

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    [ QUOTE ]
    I /ubbthreads/images/graemlins/1luvu.gif you HTC! /ubbthreads/images/graemlins/laugh.gif

    [/ QUOTE ]

    Steady on! /ubbthreads/images/graemlins/shocked2.gif

    Glad I could help.
     
  13. recomdos

    recomdos Member

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    ...heh

    hey - did you ever decide on the exhaust?
     
  14. HTC

    HTC Active Member

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    [ QUOTE ]
    ...heh

    hey - did you ever decide on the exhaust?

    [/ QUOTE ]

    Yeah. I got the Milltek downpipe and sports cat.

    I'm going to run it into the standard exhaust via an adapter that milltek made for me.

    I want the quicker spool up but with no extra noise.

    Been chatting to the yanks and this is a tried and tested setup with the K03s turbo for a little bit extra power than your average remap.

    Now, all I have to do is find the time to fit everything. Its been sitting in my bedroom for the last few months!!
     
  15. recomdos

    recomdos Member

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    /ubbthreads/images/graemlins/groovy.gif
     
  16. mnadeem1984

    mnadeem1984 Member

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    where can you get this coolant sensor from and also how much does it cost?
     
  17. imported_gek

    imported_gek Guest

    [ QUOTE ]
    where can you get this coolant sensor from and also how much does it cost?

    [/ QUOTE ]

    [ QUOTE ]
    I replaced my coolant sensor last weekend.
    Got the sensor off vagparts, plus a new o ring for just over £20.
    Had it fitted within 10 mins, it really is that easy.
    Instructions can be found here

    [/ QUOTE ]
     
  18. necroeire

    necroeire Active Member

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    /ubbthreads/images/graemlins/swear.gif I have the same symptoms since last week. Dag nammit.
     
  19. recomdos

    recomdos Member

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    [ QUOTE ]
    /ubbthreads/images/graemlins/swear.gif I have the same symptoms since last week. Dag nammit.

    [/ QUOTE ]

    well at least it is cheap to rectify and easy to fit! /ubbthreads/images/graemlins/laugh.gif It's a great feeling of satisfaction that it didn't cost hundreds! /ubbthreads/images/graemlins/smile.gif

    vagparts is your place!
     
  20. necroeire

    necroeire Active Member

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    Cheers mate. Was talking to a mechanic last night and managed to get this problem into the conversation. He told me that it's just the accelerator cable housing and that all it needs is a clean maybe with something like diesel.

    He said that it's very common and that it's just dirt causing the sensor to go a big erratic.

    I'll give it a try first and let you know rather than forking out more cash on the car.
     

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