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Mass air flow sensor - S3 (8P)

Discussion in 'A3/S3/Sportback (8P Chassis)' started by warren_S5, Mar 20, 2008.

  1. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 20, 2008]
    Yesterday my car decided to cut out on me on a motorway whilst doing a fairly legal speed. Needless to say I was quite shocked, and I managed to coast it to a hard shoulder to stop and check the car.

    No dash lights, so I started her back up and all seemed fine. When I drove it the acceleration was inconsistent and lumpy, but the engine seemed absolutely happy under no load so assumed it would be OK to get car to dealers.

    Anyway to cut long story short managed to find a local dealer to where I was (50 miles from home), and they put the diagnostics tool on it. Turns out its got an inconsistent fault with a dodgy mass air flow meter. It is due to be replaced today.

    I had no end of problems with these on my Leon Cupra R (had 2 replaced on one car in 18 months). Although they are supposed to run fine with aftermarket panel filters, it is generally accepted that the heavily oiled filters such as K&N can cause the element in the MAF some issues.

    My Carbonia panel is a dry filter so I am surprised to have seen issues. May just be a defective unit. Oxford Audi have been very good so far so a big thumbs up to them.

    Initial problems had felt like clutch slip as the car had been surging and then holding back with no apparent consistency to how it would do it. Issue got worse over time as the unit started to fail. Strangely at my 1st service a couple of weeks ago Audi Reading said they found no fault with the car (if they even checked for DTC's), but I could feel the issue starting to happen over 4 weeks ago.

    Wanted to post incase anyone else starts to get any similar symptoms. I had to drive with a very lazy car for 4+ weeks until it failed as no one could diagnose it / replicate it until it failed. Leaves you feeling a bit left in the dark really. Never mind, hopefully all sorted now, and I have had the pleasure of testing an A3 2.0TDi Quattro which is actually a really good car, very impressed by it (which is a bit sad coming from an S3, but more a reflection of the strength of the new diesels).

    cheers
    Warren
    #1
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  3. S3IZZO
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    S3IZZO Guest

    [Mar 20, 2008]
    This has been a common problem as you say from the 20vT engines, considering they've been around for getting on 10 years now you'd have thought they would have come up with a solution or at least better reliability.

    Best start carrying spare MAF's and Coilpacks around with me again :blink:
    #2
  4. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 20, 2008]
    Update:

    Still issues. Got the car back and the rev counter was flying round to 7000rpm without any real drive under full load.

    Replicated it to the dealer and the car is due back in next week for a new clutch as the dealer now agrees it slipping. Car has done 12.600 miles and I never ride the clutch so I am somewhat surprised.

    They have the car for the whole week so if I find anything else will report back.

    Can I ask, under full acceleration does anyone else hear the DV hiss slightly between each gear change or is this the start of yet another issue? I'd never noticed it before, but seems much louder now.

    Fortunately new MAF has made the acceleration much smoother.

    Big thumbs up to Audi Oxford who are being very helpful. This is the 1st decent service I've had from Audi so I am somewhat relieved.

    So that is:
    1) Spark Plugs
    2) Front O/S damper
    3) MAF
    4) Clutch

    The rear bumpers started to bow at the back and the brakes are squealing pretty badly so maybe they're next!
    #3
  5. phantom
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    phantom On Boost

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    [Mar 20, 2008]
    Ive not noticed any hissing/whistling on the S3 , so much so i think is it really a turbo? LOL

    p
    #4
  6. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 20, 2008]
    AARRRGHHH, and know I've just noticed my windscreen is cracking from the outer edge inwards. Why is it that some cars are doomed to feck you off?!?!

    Phantom, I'm sure mine didn't used to do it, just something else to add to my list of casualties. It used to be silent!

    Big deep breath and count to 10! If only everything in life was as reliable as a VW?!?
    #5
  7. phantom
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    phantom On Boost

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    [Mar 20, 2008]
    Or in yeor case mate, a Seat? Lol:)

    leon
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  8. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 20, 2008]
    You're not joking :yes:

    If someone offered me my Leon back I'd snap their arm off!
    #7
  9. DemianM
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    DemianM RWD sucks!

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    [Mar 20, 2008]
    Nice to know about other possible future issues! I still cant find what caused my remap experience to go wrong.....the car now runs like a champ on the stock map, so maybe there is a MAF or some other sensor on its way out....
    #8
  10. jamiekip
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    jamiekip Guest

    [Mar 20, 2008]
    Worrying to hear that... I'm driving to the alps tomorrow and don't want the thing forcing me to the hard shoulder on an 800 mile drive!

    I currently have the carbonio and BMC panel filter fitted. Not had any probs so far, but sods law says, if it's going to happen it'll happen at sometime in the middle of the night, in the pee'ing rain in a foreign country.... I'll be crossing my fingers!

    Keep us posted on the final diagnosis!!!
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  11. siu00adg
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    siu00adg Member

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    [Mar 20, 2008]
    Are you kidding?! Mine has always made a PsssSSSHH PSSST in each gear, less so when gunning it to high revs, but when I change around 3k its very audible.
    #10
  12. siu00adg
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    siu00adg Member

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    [Mar 20, 2008]
    Mine is still totally fine running the 330 GIAC map. I recon you should give the remap another go, mine had exactly the same error as you and, well, you read my thread.
    #11
  13. phantom
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    phantom On Boost

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    [Mar 20, 2008]
    Your DV must have a hole in it then......just like Mr cox!:)

    Only joking lads

    p
    #12
  14. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 21, 2008]
    Both my DV's do it. The Forge one and the stock one. It seemed to have got noticeably louder recently, but I have changed back to the OE panel filter which may create more back pressure (whilst its been in the stealers).

    I've noticed a slight surging at full rpm, so I suspect there could be a leak somewhere, as with all these things its finding it so I'll get them to check when they have the car apart, and if they can't sort it I will take a trip to Forge for silicone hoses all round. The OE ones aren't much cop.

    The MAF seems to be affected by a remap; on my Leon initially when I went back into stock mode it would reduce the effects of the problem, but I'm sure I read many moons ago there is a way to check whether your MAF is on the way out by using a multimeter to check (can't remember whether it was resistance) across the terminals. I'll have a search for the post. I may be dreaming so don't hold your breath.

    Its an expensive piece of kit to carry on the off-chance something goes wrong, but then I'm at the point where I now carry a small toolkit, some spare plugs, the OE DV, some oil and some jubilee clips just in case.
    #13
  15. Sand
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    Sand New Member

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    [Mar 21, 2008]
    Interesting that the standard accepted cause for MAF failures point the finger at K&N filters

    K&N have spent a lot of money and effort testing "failed" MAF sensors and have yet to find any link with their products "funny old thing that" is the obvious response but their case is well researched and worth a read , follow the link.

    http://www.knfilters.com/faq.htm#27

    No I don't work for K&N but had one on my Z3 without any problem despite all the toothsucking I heard from the peanut gallery

    Good luck with your troubleshoot , if you send your MAF to K&N I am sure they will be pleased to hear from you

    Sand
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  16. newbiecrg
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    newbiecrg windsurfer

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    [Mar 21, 2008]
    mine always hissed since day one...

    Worrying to know about clutch problems and maf sensors so early in the car's life... mine has done just over £10k miles... let's hope everything goes fine.

    Pedro
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  17. cooni
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    cooni Member

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    [Mar 21, 2008]
    you should be able to hear the wastegate letting out air as you accelerate but if this noise has become louder and you are lacking power, i'd really check over the DV to check if its popped........
    #16
  18. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 22, 2008]
    Government ministers tell us that "I didn't have sexual relations with that woman". I'm not disputing your correct, and that the research isn't independently conducted, but people who I trust to protect my investment have suggested I steer clear of K&N. As I am no expert I have to assume they are saying so for a reason, and NO they haven't then sold me another brand, I have always sourced elsewhere. With cars being as sensitive as they are these days I try to take every precaution I can, but I'm glad you didn't suffer any issues with yours.
    #17
  19. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 26, 2008]
    So it appears that I may be the first of the new S3's to suffer a clutch.

    Dealers are replacing it tomorrow so hope to have the car back Friday. 2 dealers laughed in my face when I said clutch, but then WTF do I know, I only drive it every day.

    Oxford Audi have been absolutely fantastic, so a big shout out to them for superb customer service. It's the first time I've felt like a valued customer since I walked in and showed interest in buying an S3. Alex on the service desk is new to their team but she is everything you would expect from a prestige brand, best service I've had from service to date. Not condescending, and seemingly knowledgable.

    In the meantime I'm running about in a new A6 3.0TDi Quattro S-Line with 19" RS4 alloys, and all the toys which makes the pain of being without the S3 quite bareable.

    Lets hope this is the start of trouble free motoring!
    #18
  20. julians
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    julians Member

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    [Mar 26, 2008]
    My s3 whistles quite noticeably when accelerating, has done since day 1 (now at 4000 miles/4 months old), and so did the demo I test drove. There is also a faint release of air pressure when lifting off the gas, but this is quite hard to hear.
    #19
  21. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 29, 2008]
    Cars been at dealers a week now.

    New MAF, clutch, flywheel, new windscreen.

    Dealer calls late Friday afternoon.....

    The rear diff is leaking :banghead:

    Now not planned to be back until next week. Thank god its under warranty.

    If its like this at 12,000 miles, imagine the cost of running one thats 5 years old. Once its out of warranty its gone!
    #20
  22. julians
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    julians Member

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    [Mar 29, 2008]
    The main thing that concerns me out of that list is the new clutch, did they offer a reason why the clutch has worn out at such low mileage?

    Is/Was your car modified/remapped?
    #21
  23. L60N
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    L60N Guest

    [Mar 29, 2008]
    Sorry to hear of your troubles Warren. On the plus side though, it should feel like a new car when you get it back ;)

    On the hissing front, I only hear it whilst accelerating, i dont hear the waste gate at all.

    Regards

    Leon
    #22
  24. newbiecrg
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    newbiecrg windsurfer

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    [Mar 29, 2008]
    yeah that concerns me as well... maybe drag racing? or is it faulty?

    Pedro
    #23
  25. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 29, 2008]
    No reason offered at all. I've never had a clutch replaced in any car in 17 years! I've had some cars for 60,000miles.

    I hope you're right, feel like a right Friday afternoon car at the moment!
    #24
  26. Longman
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    Longman vassdignostics.co.uk

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    [Mar 29, 2008]
    Back on the MAF issue, if you don't secure the filter housing properly and it is left to vibrate and knock, I have heard that this can damage the MAF as it is really delicate.

    I read on the Seat forum that this has been an issue with a few Carbonio and BMC owners and some have made brackets to keep better secured.

    Sorry to hear about all of the probs warren. Its a nice looking car. Its a shame these probs have lead you to want to sell it after the warantee ends. Not what you would expect from an Audi!!

    Good luck with it...
    #25
  27. warren_S5
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    warren_S5 Moderator Staff Member Moderator VCDS Map User

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    [Mar 30, 2008]
    Hmmm, sounds sensible to get a bracket on there. There is quite a bit of vibration so I'm not surprised. Cheers for the heads up.
    #26
  28. newbiecrg
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    newbiecrg windsurfer

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    [Mar 30, 2008]
    rear diff leaking..... God!! It is a new car... what is happening?

    Feel for you! I just hope we didn't buy a lemon after all it is a £30k car!!!

    Pedro
    #27
  29. jamiekip
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    jamiekip Guest

    [Apr 2, 2008]
    Can you expand on this a little?
    I have the carbonio and BMC on my car - it's just succesfully covered off a 1600 mile round trip to the alps and back without a hitch, but should I be looking out for something????
    #28
  30. Longman
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    Longman vassdignostics.co.uk

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    [Apr 3, 2008]
    In some cases I have seen, engine vibration can cause the MAF to fail so some people have made up brackets to bolt to the side of the wing from the BMC to try and reduce this.

    To be honest, with a newer car like yours, you probably won't have a problem but with older cars perhaps its worth looking at??

    It might be worth getting someone to start it while you look at the engine to see how much the filter moves about. I would imagine that to be the worst case. Normal running wouldn't be to bad, unless you are really irratic.
    #29

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