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MAP sensor & MAF sensor.

Discussion in 'A3/S3 Forum (8L Chassis)' started by SamiG, Nov 27, 2010.

  1. SamiG
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    SamiG On Boost, ish.

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    Okay i've searched the forum and google and not really turned up much.

    I'm looking to replace these two items, i know where the MAF is and i know how to change it (easy peasy) :D

    But where is the MAP sensor and how do i change that?

    I have a 2001 AMK.

    Also, what region of price is about right to expect to pay for either of these?

    I want genuine parts so if anyone has p/n's that would be useful too :)

    Thanks in advance!
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  2. Sandip
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    Sandip Active Member

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    The MAP sensor is located near the battery, if you look down near the passenger side intercooler, there is a pipe what comes off the intercooler the MAP sensor is on this pipe. It's held on by 2 allen bolts. You will probably need to buy the pipe aswell because the bolts normally get buggered.

    Any reason for changing the MAP bud, symptoms?
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  3. SamiG
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    SamiG On Boost, ish.

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    Went to RTech today to get a stage 1 map but the car is under boosting. They checked a few things and came to the conclusion that it's either the MAP or MAF sensor dude :(

    Do you know if it's a bumper off jobby to change the MAP sensor?
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  4. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    When they logged the car did they log block 115 boost request vs actual boost? Can't see how its the MAP sensor without a shed load of fault codes coming up like pressure deviation etc (17964/P1556/005462 - Ross-Tech Wiki for example)

    What airflow did you get? normal S3 should do around 180g/s rising to 200g/s once mapped... if no fault codes and decent airflow then there is something else going on IMO...

    <tuffty/>
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  5. Sandip
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    Sandip Active Member

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    No, just remove the battery and it's pretty straight forward
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  6. SamiG
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    SamiG On Boost, ish.

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    Tuffty, there were no faults whatsoever. The printout they gave me literally just shows Tq and Hp but they did mention the actual boost was a lot lower than requested boost. Up to 400MB. He didn't mention airflow.

    They tried a new N75, then tried bypassing the N75 both with no success. They smoke tested it which showed no leaks on Boost and Vac pipes. They also checked the actuator all with no avail.

    He come down to the conclusion as process of elimination that it's either the MAP or MAF sensor..
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  7. SamiG
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    SamiG On Boost, ish.

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

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    Nick has a fine reputation so while I cannot question his judgement I would have liked to know what the airflow/actual pressure readings were...

    Tough one to say but never personally heard of a MAP sensor going faulty... MAF is an easy out as they go wrong regularly enough to be warrant being a service item...

    If the actual boost was registering lower (up to 400mb) then I would still be sceptical about the MAP sensor being faulty... was boost logged on the dyno with a gauge or as part of the dyno's own logging capabilities? do you have a boost gauge?

    What was the timing pull like? seen a few cars recently with excessive oil in the charge system... try taking the pipe off the throttle body and check for oil... this and your lower boost pressure could be symptomatic of a failing turbo... they don't always blow oil straight out the exhaust... can be circulated pressure side...

    TBH I would need to see the logs before commenting any further but one suggestion would be to borrow a MAP sensor from someone if you can and eliminate that first... would like to know the airflow readings before suggesting a MAF change... had an S3 in the other day that had really low MAF readings, replaced the MAF and airflow was still down...

    Not really sure what else to suggest tbh mate..

    <tuffty/>
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  9. SamiG
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    SamiG On Boost, ish.

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    The boost reading were just given through the dyno logging.

    He also checked the TB.
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  10. s3gazz
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    s3gazz Active Member

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    had my car on vagcom yesterday and got this fault code 16497 what is this anyone tar gaz
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  11. wibble111
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    wibble111 needs to scratch the itch

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  12. SamiG
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    SamiG On Boost, ish.

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  13. tony696
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    tony696 Member

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    map is 038906051
    maf is 06A906461EX

    this web site mite help u mate

    Audi A3/S3/quattro 2001
    #13
  14. s3gazz
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    s3gazz Active Member

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    hi mate do ya no where it is by any chance tar gaz
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  15. badger5
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    badger5 RIP S3dave Site Sponsor

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    What did the logs show (boost actual vs logged via map sensor)
    Is a simple check to confirm if MAP sensor is working and correlating to measured boost...
    Logs of the engine during the dyno would have confirmed whats up surely?
    #15

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