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Intake Air Tempature reading too high - MAF?

Discussion in 'A3/S3 Forum (8L Chassis)' started by danderton, Apr 27, 2013.

  1. danderton
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    danderton Member

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    Hi,

    My S3 hasn't been running as it should so took it a local garage where we ran some test.

    Smoke test showed no boost leaks :)

    However when reading engine statistics it showed the air intake temperature as 58c. As much as i wished it was that warm it clearly isn't.

    Does the S3 have a separate air intake sensor or is it part of the MAF?

    Any one else experienced this?

    Thanks

    Dan
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  2. badger5
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    badger5 RIP S3dave Site Sponsor

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    its by throttle body on 1.8t

    stood after being run heatsoak like this would give those temps static.. drops when you drive/rev it and airflow passes by sensor
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  3. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    IAT sensor is on the inlet manifold just past the throttle body... FMIC needed really to get the temps sensible as the SMICs are a little stretched especially if your car mapped..

    <tuffty/>
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  4. danderton
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    danderton Member

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    Thanks guys, my cars not mapped.

    It wasn't sat for very long and didn't change when revved.

    Would you recommend changing that sensor then?

    Does anyone have a image of where it is located?

    Thanks

    Dan
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  5. danderton
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    danderton Member

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    Would the IAT sensor log a fault? I have no fault codes.
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  6. superkarl
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    superkarl MAN OF STEEL

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    You need to record temps on a WOT pull. Stationary means absolutely nothing.

    Standard intercoolers arent very good. Not to mention heatsoak through components.

    Unless yiure seeing 50+ on a WOT run, dont worry
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  7. danderton
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    danderton Member

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    Ok. Looking at the symptoms of IAT Sensor thou - struggling to start, and less power than normal, (poorer than normal mpg) does seem plausible.

    Unless any other suggestions?
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  8. badger5
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    badger5 RIP S3dave Site Sponsor

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    is mani hot to touch?
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  9. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    Never seen an IAT sensor go wrong unless its a wiring issue (not the sensor) or some ham fisted pillock had twated it somehow...

    IAT sensor (if non functional) will give a -48 deg reading in VCDS and will throw fault codes of some description... that said its not always the sensor and more likely the wiring...

    58 deg on idle assuming the engine up to temp and has been driven for a while is not unusal its the recovery back to sensible figures thats the tell... this can only be achieved by getting air though the SMICs so you will need to drive... if its that hot on idle then you won't recover it unless you drive the car as heat soak from the engine will just keep temps up..

    Struggling to start and down on power could be lots of things... airleaks being the prime candidates... smoke test would be advisable...

    the IAT sensor is just one that the ECU uses... if the temps are 58deg then you have to ask why rather than blame the sensor...

    Logging the car in VCDS under WOT should give an indication of where things are...

    <tuffty/>
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  10. danderton
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    danderton Member

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    Cheers Tuffy.

    I had it smoke test this morning too and found no issue. I will try getting a WOT rest and see what happens.

    Thanks Guys
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