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MAF and knock sensor problems??

Discussion in 'A3/S3 Forum (8L Chassis)' started by <tuffty/>, Nov 20, 2008.

  1. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 20, 2008]
    Hi all

    Seem to be having some probs with my car atm, went for a remap a couple of weeks ago and it seems to have highlighted a problem that I may have already had prior to the remap.

    I had a few probs with the remap which turned out to be due to the remap not taking properly and ended up being redone by taking the ECU out...

    Before I realised it was this though, I replaced the MAF with a recon Bosch unit from GSF (yes, I know!!!) and fitted new Audi coil packs and Audi plugs to see if this would cure my prob. I didn't...

    I have been back to Chipped UK today and they have done a stirling job tweaking the remap so its more progressive and ran some diagnostics too (many thanks again) however on the drive home and while not really thrashing the car the ESP light came on so I pulled over and restrated the car and it went off only to come on again a little while later.

    I VAGCOM'd the car when I got home and got:

    VCDS Version: Release 805.1

    2 Faults Found:

    16487 - Mass Air Flow Sensor (G70): Signal too High
    P0103 - 35-10 - - - Intermittent
    16712 - Knock Sensor 1 (G61): Signal too High
    P0328 - 35-10 - - - Intermittent

    Readiness: 0000 0000

    Does this mean that I have a naff MAF and knock sensor? or just the knock sensor fault is due to a naff MAF?

    GSF have said that they can't take the MAF back as its exchange and my old one is long gone. They can sell me anouther and then if the previous one is found to be faulty then they will refund me. I even called Parklands Audi and they only do exchange units too.

    I am not really sure what to do next. Anyone got any suggestions as the car wants to go but when the boost kicks in there is a definate feeling of it holding back.

    Thanks in advance

    <tuffty/>
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  3. h100vw
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    h100vw Member

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    [Nov 20, 2008]
    You need to monitor the MAF with VAG-COM to see what it's doing. Same with the knock sensor.

    You guys at chipped uk should be the first port of call, to stop you blowing money on stuff you don't need. Far better to diagnose the problem first.

    Gavin
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  4. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 20, 2008]
    Thanks mate, do you know the best way to go about this? Chipped UK ran some MAF tests on the dyno and it suggested that things were flowing ok in so much that the mg/s readings were right for the power etc, just seems that when the boost comes it can't handle the initial request for air then indicates that things are flowing ok... I am of course not talking from any form of knowledge as I am a complete n00b at this (Only had the car about 2 months and VAGCOM about 2 weeks)

    Cheers

    <tuffty/>
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  5. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 21, 2008]
    Is there anyone in the Gloucestershire area that would be happy to swap out their working MAF just to prove if it is actually the MAF on my car thats buggered as GSF won't refund without proof :(

    Guessing you would need to have an AMK engine like mine as the parts maybe different...

    Cheers

    <tuffty/>
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  6. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 21, 2008]
    Additional info while I remember. I am running a Forge 007DV with yellow spring and a pipercross airfilter. One thing I have noticed is that DV noise has increased due to the airfilter (normal so I am told) but this morning I noticed a kind of screeching noise too when the turbo boosts up. Its not a mechanical screech and only really does it if I stick the boot in so I don't think its the turbo on its way out.

    Any ideas?

    <tuffty/>
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  7. h100vw
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    h100vw Member

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    [Nov 21, 2008]
    Have you cleared those faults out? Did they come back?

    Gavin
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  8. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 21, 2008]
    Yes I did and yes they have :(
    Seems to me that when boost kicks in, the MAF doesn't read the volume of air correctly and the mixture leans out as it fuels for a lesser vol of air, the knock sensor then kicks in and retards the timing causing the loss of power but due to the remap and increase of air required it makes the knock sensor fault as the reading is above normal params. I could of course be talking ****** as my previous tuning experience is based on ford pinto engines, cams and side draught carbs (old skool) no knock sensors, just pinking :p

    <tuffty/>
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  9. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 21, 2008]
    Does anyone have the correct Audi part number for a 2001 AMK engined S3 so I can try and source a brand new MAF rather than the recon **** that everyone seems happy to sell?

    Ta

    <tuffty/>
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  10. h100vw
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    h100vw Member

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    [Nov 21, 2008]
    Have a look at the boost, timing retard and airflow all at the same time. I can't remember the measuring blocks they are in but if you log into the engine ECU you can scroll through them one at a time.

    Go for a drive, need to do a long run from 2000 revs, before boost has built up to the red line if you have enough road. If you can do it in 3rd and uphill.

    After that maybe try it again looking at Lambda instead of boost.

    Have a look at the logs and see what you see. Timing retard should be less than 6 degrees or so.

    I had an A4 that I chipped and the MAF only played up under boost and the airflow would intermittently drop to zero and it went like a std car. Fitting a new MAf cured that fault.

    Gavin
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  11. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 21, 2008]
    Cheers gavin, I'll have a pop over the weekend.

    Paul
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  12. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 22, 2008]
    Bah!!! the saga continues... car went into limp mode again today, VAGCOM came up with a new fault this time...

    17963 - Charge Pressure: Maximum Limit Exceeded
    P1555 - 35-00 - -

    Getting silly now :(
    #11
  13. Essflee
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    Essflee Well-Known Member

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    [Nov 22, 2008]
    My car used to have that fault come up, it's to do with there being to much boost, the turbo shuts down to save any damage being done....i never solved the problem till i took it to be remapped...since then i've had no issues.

    Don't let it get you down, i had all sorts of issues when i bought mine which really cheesed me off too, but like i said, since the remap everythings been ok.....(touch wood)
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  14. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 22, 2008]
    Thats the problem, mine has been... :(
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  15. Essflee
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    Essflee Well-Known Member

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    [Nov 22, 2008]
    Where did you take it ? i had mine remapped when i bought it, then had problems, and within weeks took it to another company who redid the map and everythings been alright...
    #14
  16. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 22, 2008]
    Got it done at Chipped UK.
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  17. Essflee
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    Essflee Well-Known Member

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    [Nov 22, 2008]
    It might be worth going back to see them, it could be a manner of things but the remap worked for me....i've had the knock sensor issues too which my local specialist reckons isn't a very common problem, i think there's 2 knock sensors from what ive been told.....the first few weeks of ownership there always seemed to be something.....
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  18. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 22, 2008]
    Tell me about it!!! I am seriously tempted to get the remap removed and make sure the car is ok in std power.

    I may get another MAF though but it would be real useful if I could just swap mine out with someone else's just to see if it would make any difference.
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  19. h100vw
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    h100vw Member

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    [Nov 22, 2008]
    Could be a wastegate problem. If the wastegate is stuck shut or not opening when it should?

    Or even the N75 I think is supposed to open the wastegate if it is told to.

    It's the canisitor on the side of the turbo. If you can get to suck on it it should move the actuator rod. In fact the rod should move by hand with very little force.

    I'd go to chipped uk and have them look at it. Expect them to charge if they find it's not related to the MAP and wasn't a problem in std trim.

    Do you have a boost gauge fitted. Have you logged anything yet?

    Gavin
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  20. jimbobery
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    jimbobery S3

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    [Nov 23, 2008]
    If you've got vagcom its really easy to work out if your MAF is ok.
    My S3 has been mapped by ChippedUK in Bromsgrove. Previous owner did it but he did say they were really helpful.

    My MAF failed - full story here:
    http://audi-sport.net/vb/showthread.php?t=58999

    I've got a word document that tells you how to log your MAF - pm me your email and I'll send it to you.
    #19
  21. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 23, 2008]
    PM'd :)

    Been paid now so hopefully have some spare cash to get another MAF, from Audi this time..
    #20
  22. h100vw
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    h100vw Member

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    [Nov 25, 2008]
    Have you proved that's the problem? I would go spending the money without doing so.

    A shot MAF would play up with the std map or chipped one. Admittedly you may not have noticed.

    Gavin
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  23. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Nov 25, 2008]
    Not yet... got a load of info from deece so I am gonna have a pop at logging it all in VAGCOM when I get a spare 1/2 hr this week. Failing that I am going to take it to a VAG specialist tuners near my brothers pub so I can drown my sorrows and get the car fixed (hopefully).

    <tuffty/>
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  24. h100vw
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    h100vw Member

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    [Nov 26, 2008]
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  25. <tuffty/>
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    [Nov 28, 2008]
    Righty... done the checks although not really 100% on my ability to understand the figures but seems to be a combo of dodgy MAF and/or boost leak. So... got a silicon TIP this week and I am gonna fit that and check out all the pipes too.

    Once I have done that, I will see if that fixes the issue else its off to Audi for a pukker MAF.worries me at the moment is the intermittant screech I get while the turbo is boosting. I have done a quick search and it would appear that screeching could be... Bad!

    This is intermitant though but seeing as my car seems to either be backing down from boost related issues or in limp mode then its difficult to tell if this is a permenant problem.

    Assuming every thing was ok and limp mode/MAF issues were non existant, does anyone know what the screeching could be?

    Ta

    <tuffty/>

    The only real thing that
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  26. <tuffty/>
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    [Dec 23, 2008]
    OK, now have an Audi sourced MAF and has made a load of difference but still not fully cured the problem.

    I did the cambelt over the weekend and took the opportunity to check all the boost hoses, nothing obvious but I undid them, cleaned them up and tightened the clamps up again so hoped that would cure any potential boost leak issues.

    Problem is still there. Intermittent as ever but still there. Actually got around to jury rigging my boost gauge in to see what is going on, spikes to 1.5 bar then holds at around 1 bar. The squealing noise is still there and when it happens power drops off.

    After a bit of research and discussion with various peeps, problem could be related to the remap (map) or possibly the turbo oil feed pipe. It seems like the noise is the turbo either spinning too fast from too much boost from the map which also ties into vagcom showing 'charge pressure exceeded' faults and MAF 'upper limit exceeded' faults or possibly obstructed oil feed pipe that intermittently cannot supply enough oil causing the turbo to complain.

    I have spoken to Mark at Chip 'n' Spin who suggested removing the map and trying the car for a week std to see if it cures the prob and also offered a full refund. I am not convinced this will highlight the problem even though it may prevent the faults and turbo squeal initially. I really need to find out if the turbo is buggered or the oil feed pipe is blocked or its just a **** map...

    Any suggestions? I do not want to spend out needlessly as I can see me just changing the turbo and the oil pipes and it still not fixing anything.

    For the record, the car was on AVS servicing before I got it. I am now changing the oil every 5k and due to do one after Christmas.

    <tuffty/>
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  27. Essflee
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    Essflee Well-Known Member

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    [Dec 24, 2008]
    Its good that Mark has agreed to give you a full refund on the map...that would be my move, see how the car runs in standard form.....and keep your fingers crossed.....a map can play all kinds of havoc if the car hasn't taken to it !!
    #26
  28. <tuffty/>
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    [Dec 24, 2008]
    I will be contacting Chipped UK in the new year to get that sorted but still looking for advice and direction about the squealing noise.

    One thing I am tempted to do is perhaps try engine flush of some description. I really didn't like the idea of AVS servicing and a little worried its clogged stuff up.

    Does anyone know of a suitable engine flush product I could try? Would removing the turbo oil feed pipe and cleaning it out be of benefit and how dificult is this?

    I will get the car put to std to see if there are any further probs but still really concerned that the damage has already been done or at least will happen no matter who maps the car and really want to get that sorted.

    Ta

    <tuffty/>
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  29. mateik
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    mateik New Member

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    [Dec 5, 2009]
    hi

    I get the same error code on my car, it`s a 2000 tt that has been maped to 270 hp. I get the errorcode P0103 or 16487.

    The thing is that I have just a week ago changed my MAF at a shop and the car did not get any bether.

    My problem is that the engine cuts when I drive normaly increasing the gas. But when I floor it it works greate.

    Do anyone know what does this?? I would gues that it`s a airleak on the hose from the MAF to the turbo?? can anybody help me pleace.
    #28
  30. m444ty p
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    m444ty p Member

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    [Dec 6, 2009]
    My s3 had a new turbo due to the oil feed getting blocked. The owner before me said the turbo made all sorts of noises before it gave up the ghost.
    #29
  31. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Dec 6, 2009]
    Does anyone know if Tuffty ever got this sorted before he went BT? Tuffty?
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  32. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Dec 6, 2009]

    Mine turned out to be an issue with the map so I had it removed and got Custom Code instead... Never
    had the MAF problem after that

    The knock sensor issue was resolved by simply rewiring it back to the ECU

    <tuffty/>
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  33. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Dec 6, 2009]
    Perfect timing. :)

    did you ever find out why the turbo was screeching?
    #32
  34. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Dec 6, 2009]
    It was cavitation, the turbo had reached its volumetric capacity which is typical on a mapped K04.

    Custom Code improved the situation but didn't cure it completely.

    That was one of the reasons I went BT rather than hybrid.

    K04 is just too small to run high power efficiently.

    <tuffty/>
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  35. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Dec 6, 2009]
    Ok so not the end of the turbo due to oil starvation, phew! I have a chipped uk map and I also get the same hi pitched screeching sometimes on full whack. I've not been worried about it as I just assumed it was the map until I read this thread!
    #34
  36. Essflee
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    Essflee Well-Known Member

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    [Dec 6, 2009]

    How simple a job is that for a novice tuffty as my car still chucks out this fault ??
    #35
  37. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Dec 6, 2009]
    Dunno how I would define it... Basically you need a length of shielded 2 core cable and you solder this to the plug of the knock sensor and run it back to the ECU where you cut the original wires and solder it to them.

    I had access to ElsaWin so was easy enough to find the right wires but I guess its how happy you are to solder etc.

    I used 4 core individually screened cable from Maplins, twisted them in pairs. There is no connection needed for the screen just 2 connections for the sensor. Cut the plug off at the sensor end leaving enough solder the new wires too... solder and tape up making sure its taped enough to give it some strain reflef.

    Run the wire back to the ECU, choose a path that means its well protected and not going to get in the way. I ran mine to the conduit that runs under the airbox and into the scuttle. You can get away with not removing the airbox to access the top part of the cover.

    Remove the passenger wiper blade to allow access to the ECU. The smaller plug on the passenger side had the wires I needed for my AMK engined S3, not sure if they are the same on a BAM but would have thought so...

    Wiring diag from Elsa..
    [​IMG]

    Pins 99 and 106 were the right ones for mine. I took the cover off the plug after removing it from the ECU then cut the wires long enough to solder to them.

    Put it all together and jobs a good un.

    <tuffty/>
    #36
  38. Essflee
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    Essflee Well-Known Member

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    [Dec 6, 2009]
    Cheers for the response mate, I'm not going to lie though, some of that has gone straight over my head, think I'm going to have to uncover the ecu and see what I'm dealing with, failing that I'll get someone to do the honours for me...lol
    #37

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