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

A4 1.8T -Idle speed fluctuating and Camshaft Position Sensor fault!

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by AudiStew, Sep 2, 2010.

  1. AudiStew
    Offline

    AudiStew New Member

    Joined:
    Sep 2, 2010
    Messages:
    3
    Likes Received:
    0
    [Sep 2, 2010]
    Hello!
    I have a A4 1.8t which developed a starting problem and an engine management fault (camshaft position sensor), took it to my local VW/Audi specialist who after a week failed to find the cause. My next step was to take the car to a tuning specialist, they also struggled to find the cause of the problem and after two weeks advised me to have the cars chip replaced. On completion of this I was told the starting issue had been fixed, this was true as it started first time! unfortunately this is not the end of my headache as the engine management light is still on (same fault) and worst of all the cars rpm's are all over the place when ticking over.
    Any help would be greatly appreciated!
    #1
  2. Ads

    Ads

    [Nov 23, 2014]

  3. S3PEG
    Offline

    S3PEG Member

    Joined:
    Jan 15, 2008
    Messages:
    101
    Likes Received:
    0
    [Sep 2, 2010]
    I recently found that my a/c compressor was siezing and putting a strain on the engine causing the revs to bounce all over the place... could be worth checking. Mine has just been disconnected for now undtil I find a second hand replacement. Good luck!
    #2
  4. itsmeagain
    Offline

    itsmeagain 1.8T Sport Cabriolet

    Joined:
    Mar 6, 2010
    Messages:
    439
    Likes Received:
    0
    [Sep 3, 2010]
    Mine was diagnosed with the same fault, I was advised to try the coil packs as I had a misfire on cylinder 3. After changing the coil packs its fine, runs smoother now.
    #3
  5. S3PEG
    Offline

    S3PEG Member

    Joined:
    Jan 15, 2008
    Messages:
    101
    Likes Received:
    0
    [Sep 6, 2010]
    Interesting! Do you remember if there was a fault code or not?
    #4
  6. CHRIS555
    Offline

    CHRIS555 DOPE with added OCD

    Joined:
    Jul 4, 2010
    Messages:
    1,941
    Likes Received:
    2
    [Sep 6, 2010]
    I'd put money on it being your CRANCASE BREATHER VALVE - it's buggered. I had the same thing, when the car is moving all is well, but when at idle it feels like the wind is battering it! Audi NEVER seem to diagnose this fault - they always look at pipes, coil packs, boost leaks etc first! It's a real simple fix, you can DIY for less than a fiver and then have your fault codes re-read and the engine management light will not come back.

    If you need the part numbers, fault codes and know how, let me know! I will copy and paste a thread for you to read through as well from when I had my problem.
    #5
  7. CHRIS555
    Offline

    CHRIS555 DOPE with added OCD

    Joined:
    Jul 4, 2010
    Messages:
    1,941
    Likes Received:
    2
    [Sep 6, 2010]
    Hi I have a missfire from my car at Idle. When in motion all seems okay but when at idle the car shakes around (like the wind is hitting it) and the exhaust garbles along with the missfire.

    It is stage one tuned with a Milltek Cat Back system, remap and carbonio. I've had the throttle body cleaned and reset and recently changed the diverter valve at the top of the engine due to the old one leaking/hissing.

    The car has been in today and been serviced along with new plugs. The fault codes have been read and are as follows:


    18062 – Please check DTC Memory of Instrument Cluster
    P1654 – 004 – No signal / communication – Intermittent

    (If it helps I recently took the ECU Fuse out by mistake!)

    17544 Fuel Trim BANK 1 (Add) System too lean
    P1136 – 001 – UPPER LIMIT EXCEEDED – MIL ON

    16891 – IDLE CONTROL SYSTEM RPM – HIGHER THAN EXPECTED
    P0507 – 001 – UPPER LIMIT EXCEEDED – INTERMITTENT

    17705 – PRESSURE DROP BETWEEN TURBO AND THROTTLE VALVE (CHECK D.V.!)
    P1297 – 001 – UPPER LIMIT EXCEEDED

    16684 – RANDOM/MULTIPLE CYLINDER MISSFIRE DETECTED
    P03000 – 008 – IMPLAUSABLE SIGNAL

    16685 – CYLINDER 1 – MISSFIRE DETECTED
    P0301 – 008 – IMPLAUSABLE SIGNAL

    16686 – CYLINDER 2 – MISSFIRE DETECTED
    P0302 – 008 – IMPLAISABLE SIGNAL

    Also, the CAT does appear to glow quite a bit!

    I only use 99ron super unleaded fuel.

    Any advice or suggestions would be most welcome!

    ++++++++++++++++++++++

    Hello my friend,

    You have the classic crankcase breather valve problem.

    Its a valve that is inside a T piece pipe near your oil filter/under manifold

    Basically your car is running lean at idle when you stop, a valve doesnt close and your engine is flooded with air, and not enough fuel, hence jerking, also because of this problem it will have broken your Pressure regulating valve (PRV) black disc at the back of the engine (£25) that is causing the pressure drop between the turbo and throttle valve, I went through 3 or 4 of these whilst I had the problem

    [​IMG]
    http://www.ecstuning.com/Search/Cran..._Valve/ES5957/


    [​IMG]
    http://www.ecstuning.com/Search/Cran...alve/ES258895/

    Do a search on crankcase breather valve and you will find a thread I made a while back


    Took me over 6 months and £600 to fix it, if I had known the fault straight away looking at £50 all in, aslong as you dont break any of the brittle rubber pipes attached to the breather valve, might be an idea to change them aswell



    Audi charged me £280 robbing feckers

    PRV £25
    Breather valve £20
    New clips etc etc £5

    ++++++++++++++++++++++++++++++++

    Update - SORTED!!!

    Big shout to Balckpool1974 - without you I would not have solved this, nor would my garage and nor would my wallet!

    I located the valve (hidden inside the t-junction pipe beneath the intake manifold) and after some effort getting between al the other hoses and pipes (thank god I have skinny wrist's!) I manage to remove the old one and fit the new one. The car now runs as though it is brand new and is certainly a lot quicker!

    The old one had broken. The flap inside had collapsed and basically remained open at all times from when I can see. I took a photo of the old and new next to each other to help anyone else in the future as below.

    If you decide to do this repair yourself the Part Number is 035 103 245 G and is currently £6.70 + VAT. If you are off a big build I will say that there is not much room to do this job - you really have to get between a lot of pipes and hoses all very close together in a small space without much sight of the object - you can remove the other hoses but this will all take a long time. Make sure you allow your engine a few hours to cool down as well.

    +++++++++++++++++++++++++++=

    LET ME KNOW IF YOU NEED ANY HELP IDENTIFYING THE LOCATION OF THE VALVE!!
    #6
  8. AudiStew
    Offline

    AudiStew New Member

    Joined:
    Sep 2, 2010
    Messages:
    3
    Likes Received:
    0
    [Sep 9, 2010]
    Thanks for your time CHRIS!
    (i will have a look on my days off)
    #7
  9. AudiStew
    Offline

    AudiStew New Member

    Joined:
    Sep 2, 2010
    Messages:
    3
    Likes Received:
    0
    [Sep 9, 2010]
    I cant remember the actual code (sorry), all i know is the fault description "camshaft position sensor"
    #8
  10. S3PEG
    Offline

    S3PEG Member

    Joined:
    Jan 15, 2008
    Messages:
    101
    Likes Received:
    0
    [Sep 9, 2010]
    This thread has been really useful - Chris555, do you know the part no of the PRV that you mention in your post?

    Thanks.
    #9
  11. itsmeagain
    Offline

    itsmeagain 1.8T Sport Cabriolet

    Joined:
    Mar 6, 2010
    Messages:
    439
    Likes Received:
    0
    [Sep 11, 2010]
    I went to Audi and got the valve, but I must be stupid cause I cant find where its located.
    #10
  12. CHRIS555
    Offline

    CHRIS555 DOPE with added OCD

    Joined:
    Jul 4, 2010
    Messages:
    1,941
    Likes Received:
    2
    [Sep 11, 2010]
    No your not stupid, it's realy difficult to find! Stand in front of your car and look at the engine. You have the main block in front of you. Look to the right of it towards the top and look at the pipes underneath - basicall lean over your engine and look at the pipe to the right hand side - the valve is in a pipe itself - i will try and photo mine and will email you a picture - PM me your email address!
    #11
  13. CHRIS555
    Offline

    CHRIS555 DOPE with added OCD

    Joined:
    Jul 4, 2010
    Messages:
    1,941
    Likes Received:
    2
    [Sep 11, 2010]
    Hi there, I will get you the part number in the morning no problem
    #12
  14. CHRIS555
    Offline

    CHRIS555 DOPE with added OCD

    Joined:
    Jul 4, 2010
    Messages:
    1,941
    Likes Received:
    2
    [Sep 11, 2010]
    I've just put a thread in this section called "Crankcase Breather Valve Location" with pictures etc - hope it helps!
    #13
  15. murran
    Offline

    murran Active Member

    Joined:
    Aug 10, 2010
    Messages:
    1,540
    Likes Received:
    35
    [Sep 11, 2010]
    this is really easy to diagnose tbh. cant think why a garage would struggle to work it out!
    first off, with it ticking over, take the oil cap off.... does that make a difference to the idle? it shouldnt.
    place the cap back on (without twisting it) try pulling it back off, does it seem to be held on at all by suction? it shouldnt be.
    ultimatley once youve found the valve in the breather "t" piece under the inlet manifold, trace the smaller pipe up to the inlet manifold. get a pair of long nose pliars/mole grips and clamp the pipe..... does it make any difference to the idle? it shouldnt make any difference.

    if it does then the vacuum in the inlet manifold is subjecting the crankcase to too much vacuum cus the said one way valve is knackard.
    takes about 2 minutes to diagnose!

    youd have misfire faults and fuel trim too lean in the memory. not really cam sensor faults?
    Last edited: Sep 11, 2010
    #14
  16. itsmeagain
    Offline

    itsmeagain 1.8T Sport Cabriolet

    Joined:
    Mar 6, 2010
    Messages:
    439
    Likes Received:
    0
    [Sep 12, 2010]
    Just changed my faulty valve, it looked knackered. Engine management light is off now and it seems to idle fine now. I wish i had tried this first before changing the coil packs.
    #15
  17. CHRIS555
    Offline

    CHRIS555 DOPE with added OCD

    Joined:
    Jul 4, 2010
    Messages:
    1,941
    Likes Received:
    2
    [Sep 12, 2010]
    06A 129 101 D
    #16

Share This Page