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MAF Problems

Discussion in 'A3/S3 Forum (8L Chassis)' started by kevy, Sep 4, 2007.

  1. kevy
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    kevy New Member

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    Hi,

    I have had a bit of trouble with my MAF sensor lately and need a bit of advice.

    About a month ago I was getting hesitation when accelerating steadily, but I couldn't really notice it when I had my foot down. Checked on the forums and found a few people with the same thing that suggested I unplug the MAF sensor to see if things got better.
    That seemed to work, so I went to Audi to get a new MAF. Replaced it myself, but it was still ****. Unplugged it again and acceleration was fine. It did look like it had been fitted to another car before as it had a bit of grease on it, so I took is back to Audi.
    They had the car in and ended up replacing the MAF.

    When I got the car back it was all fine for 2 or 3 days, when it started playing up again.

    Surely I can't have another faulty one can I?

    I have a REVO remap and thought this might have something to do with it.

    Has anyone else had the same problems and is there a different MAF I can use to cope with the higher power?
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  2. S3 Dave
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    S3 Dave Now running on Heavy Oil

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    Had problems with MAF's before. What Air filter do you have?? Re-maps and non stock filters seriously shorten MAF life!! If you have a K+N etc the oil from these can kill it!. If you got it fitted at Audi then I would take it back. All parts with 2 year warranty etc!!! Had mine changed under warranty after 22 months!
    #2
  3. jojo
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    jojo S3 Drift King! Staff Member Moderator

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    It seems clear to me that your MAF is at fault, as you say it was running fine for 2-3 days, then goes faulty again.
    Note likely, but it's not impossible to have a faulty MAF again bud.
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  4. shineydave
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    shineydave Member

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    i had a faulty MAF replaced which subsequently went faulty, got a replacement FOC and that was faulty also, the third one has been fine
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  5. S3quatt
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    S3quatt Flat Oot like a ducks Foot

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    One question on this issue.

    Does a knackered MAF cause a lumpy idle too?

    Just had my throttle body off & cleaned but doesn't seem to have helped.
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  6. kevy
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    kevy New Member

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    It seems to on mine, yes. Only slightly though.
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  7. kevy
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    kevy New Member

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    My air filter is standard so it shouldn't be that causing a prob.

    Another thing is, I reset the ECU the other day to try and get the one touch on the leccy windows working and the car seemed run fine again for a few days. But now it's poo again.

    Anyone know why this is? Something to do with the ECU learning??
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  8. kevy
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    kevy New Member

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    Finally Audi had tracked down the problem to a leak on one of the vacuum hoses.

    They quoted me £450 for the work and £150 for parts claiming they need to remove the inlet manifold to do the work.

    I told them no of course, but now I need some help.

    Firstly, I need a pointer as to where I can get the hoses cheep, and or better hoses?
    Secondly, do I need to remove the inlet manifold to replace these? Is it an easy job?

    Audi recommend I replace all my vacuum hoses and I do agree on this one as it's done over 100k.

    Thanks in advance for any advice.
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  9. flippy
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    flippy New Member

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    Any update and conclusion for this topic, my S3 also has same problem no matter i change my MAF to new one and still problem, unless i unplug.
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  10. HTC
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    HTC Active Member

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    When you swap the MAF to a new one you have to reset the ECU. This is why you didn't feel the difference before.

    Lumpy idle = vacuum leak as mentioned.

    You do not need to remove the inlet manifold to replace the vacuum pipes underneath it. I'm surprised they said that. You can remove the various engine covers and then the black metal plate that attaches to the inlet where the oil dip stick sits and you'll have room to get to things.

    You might find that it's either one of the two thin vacuum pipes or part of the breather system that's split. I've had to fix both in the past.

    Also the v shaped pipe on the drivers side next to the cam cover is a common one to fail on the S3. That's a very easy one to get to.

    You don't need to replace them all by the way, just the faulty one(s).
    #10
  11. flippy
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    flippy New Member

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    Instead of reset ECU, i did the Throttle Body Alignment (TBA) via VAGCOM instead which i believe ECU should re-learn the new figure but seems i didn't see any change, more funny is even no DTC show when new MAF / old MAF plug. Hope the vaccum leak thing u mentioned can help. but that part i need ask my garage do so, do you have any more detail about it ?
    #11
  12. 1.8tplym
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    1.8tplym Member

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    BUMP

    I think i am having the same problem as these guys a few years ago. The engine Mgt light has come on recently. When i start the car it will quite often run rough (like its being overfuelled) for about 20 seconds but seems to clear once underway? my idle is also a bit carp. It coughs every few seconds but not bad enough to stall the car. MPG is in around 25 but i only do to work and back at about 30mph. I put a K+N panel on so i reckon the oil has destroyed the MAF. If i unplug the maf all does seem to improve.

    so the questions are -

    Im guessing best bet is to change the Maf? (cheaper than the hoses)
    I have read elswhere that it is best to buy a new MAF from the stealers rather than ebay/ gsf etc?
    What price should i pay. about £100 inc vat?
    I guess they are easy enough to fit, its only the barrel leading into the air box?
    And how do i res-set the ecu. Is it just unplug the battery for 15 minutes?
    Should i ditch the K+N and if so replace with what?

    That should do me for now!

    Any help much apreciated.
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  13. 1.8tplym
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    1.8tplym Member

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    Oh, and no ribbing because its a five door!!!!!!!
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  14. s3dave
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    s3dave TFSI Hybrid

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    I removed mine and gave it a good spray with fuel injector cleaner , blew it dry with an airgun and presto!! different car :icon_thumright:
    #14
  15. 1.8tplym
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    1.8tplym Member

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    That sounds even cheaper! trip to halfords this afternoon i think! i take it you just removed the barrel and sprayed all over? did you leave it to dry and did you reset the ecu? im full of questions today!
    #15
  16. S3 Nattie
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    S3 Nattie Quattro ist für sissies

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    This exactly the same problem as I have, replaced the MAF but still runs the same. I think I may also have a vaccum leak.

    Every now and then when I put my foot down it seems to make more noise than go. Sometimes its quick sometimes its not but it does feel better with the MAF unplugged. I replaced that and it didnt make a difference so got my old one back.

    My car also sounds like it overfuelling when I take off sometimes weather the MAF is plugged in or not.

    Stumped now.
    #16
  17. s3dave
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    s3dave TFSI Hybrid

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    yes removed it and sprayed it, i made sure the fluid did not go into the electrics... hold it so the prong is pointing to the floor and spray both sides..it should evaporate but i used an airgun too as i was in a rush, i reset the throttle body adaptions on my liquid guage :icon_thumright:
    #17
  18. finesse
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    finesse Active Member

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    Pick one
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