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False Knock

Discussion in '2013-14 Shelby GT500' started by mebetter, Mar 1, 2017.

  1. mebetter

    mebetter Member Established Member

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    Trying to trace the false knock on my 2013. Mods are JLT CAI and FRPP dual blade throttle body. The tuner is saying 9/10 times it's the exhaust; but my exhaust is completely stock. Has anyone had a problem with the stock exhaust causing false knock?
     
  2. 02GTKB

    02GTKB Nolimits Established Member

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    Could be multiple issues including the fuel quality which usually is the main culprit..These years have had the problem of oil blow by from what I have read, and contaminates the intercooler below the s/c if not running a good oil separator, causing poor fuel quality which is most likely the cause of the knock sensors..when are yours going off? what rpm?
     
  3. mebetter

    mebetter Member Established Member

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    At wot it's seeing 2 counts of knock between 4k and 7k, at part throttle it sees up to 4 counts of knock from 2k - 5k rpms. I added a tank of 101 and knock is still the same. I'm thinking perhaps it's spark plugs or the maf?
     
  4. Slow Five-O

    Slow Five-O Member Established Member

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    Your tuner could be right, even with stock exhaust. From the factory, the bolts that connects the bottom of the cat to the h pipe are upside down and tap the car and often this is where false knock comes from.


    EDIT: I just realized I accidentally ventured into the gt500 forums. The above statement goes for the coyotes and I'm not sure if it applys to the trinitys as well. Worth looking into though.

    Sent from my iPhone using Tapatalk
     
  5. Slow Five-O

    Slow Five-O Member Established Member

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  6. mebetter

    mebetter Member Established Member

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    Location:
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    Thanks for the help guys. I did see where the heat shield may have been rattling against the body of the car. The fix was that I was actually datalogging the wrong PIID. I was logging global knock and should have been logging my knock sensor. Actual knock was only .25 and not 2+.
     
  7. 02GTKB

    02GTKB Nolimits Established Member

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    Oh then that is not much to worry about, could just be the fuel if that
     
  8. Black Thunder 715

    Black Thunder 715 Member Established Member

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    Nice video and good info. Thanks.
     
  9. 03kbredfire

    03kbredfire Member Established Member

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    richland washington
    Sure is nice to see a tuner help out the community like this.
     
  10. Grabber07'

    Grabber07' Member Established Member

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    Glad you got it sorted Teddy!
     

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