1st Gen R53 Cooper S False knock sensor issue/exhaust rattle?

Discussion in '1st Generation: 2002–06 R50, R53 & 2004–08 R52' started by jasonsmf, Aug 23, 2011.

  1. jasonsmf

    jasonsmf Active Member

    Jun 12, 2009
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    In a thread just below, I had asked for tips replacing my knock sensor (06 R53), now I have a slightly different question:

    What are the chances of an exhaust rattle causing a faulty knock sensor SES light (P0326)?

    On Saturday, I replaced a faulty Hushpower muffler, the internals had failed and it was full of chunks that were rattling around and sounded terrible. This rattle began in June and has been getting progressively worse since. This hushpower was mounted immediately behind the stock cat at the flange. I replaced it with a 5" diameter magnaflow muffler. Rattle cured, and the SES light has been out since Sunday. It seems to me that the knock sensor is listening for a very specific frequency and an exhaust rattle shouldn't matter, this might be purely a coincidence. I'm waiting for a return of the SES light at any moment. Has anyone experienced this?

    Thanks again,
    Jason
     
  2. Crashton

    Crashton Club Coordinator

    Jun 4, 2009
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    I think that is possible. Jason you are the wizard of rattles. :Thumbsup: Well done!
     
  3. HRM

    HRM New Member

    Mar 16, 2011
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    I certainly would clear the code a few times before I did something about it.
     
  4. minimark

    minimark Well-Known Member

    Jun 24, 2009
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    Did you just clear the code or have you had the adaptations cleared? If it is an adaptive code and you haven't cleared the adaptation the code will keep coming back... 2cents
     
  5. KC Jr 54

    KC Jr 54 New Member

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    Did the seat of your pants say the car feels faster ? Maybe the failed muffler caused excessive back-up and actually caused knock w/in the motor ?

    Just a far fetched theory, but maybe...


    Jason, what does your exhaust consist of now ? I would be very interested to hear a clip if possible too.
     
  6. jasonsmf

    jasonsmf Active Member

    Jun 12, 2009
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    I actually didn't clear the code, the SES light went out on it's own after the muffler install. When I scan I have no pending codes, MIL status is off, although the P0326 is stored. How do I know if this is an adaptive code?

    Thanks,Jason
     
  7. jasonsmf

    jasonsmf Active Member

    Jun 12, 2009
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    I don't think there was any back pressure issues, as I could still see light thru the Hushpower and I didn't notice any loss of power.

    I'll have to work on getting a clip, but the system is all 304 Stainless, 2.5" from the flange back. 5" diameter x 14" body magnaflow right behind the flange, homemade spiral flow type baffle in the pipe under the gas tank, 11" oval body magnaflow on the rear passenger side, exiting "justa Cooper" style. 1/4 wave side branch resonator helps keep the drone in check.

    Jason
     
  8. minimark

    minimark Well-Known Member

    Jun 24, 2009
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    If it is stored I'm pretty sure its an adaptation plus a bad knock sensor probably would be. I had a P code that was a stopped up cat. Replaced the cat and cleared the code with a normal scan tool, after a bit it would cycle through and the light would come back on. Jan told me to get the adaptations cleared, Blimey cleared them with his Autoenginuity and no codes, no lights months later.... Dealer's want to rob you to clear them and make out like it takes a long time...took Paul about five minutes....

    The Autoenginuity is at the top of my want list...
     
  9. HRM

    HRM New Member

    Mar 16, 2011
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    I can't argue the adaptation/or not angle since I just don't know enough, but, I can say at a restart I did get the code a month or so ago and it hasn't come back and I can't sense any difference in the car. I just cleared it with a scanguage, now it says "no codes" and my SOP is forget it unless it reminds me.

    I think some codes are retained for the tech. My buddy (mini tech) when he worked on my wife's car said the right front ABS sender had tossed a bunch of codes. Some types include mileage in the report to help diagnose. This one did not, but wife has never mentioned any lights, so I figure it was a note from way back that was never cleared.

    Sorry I can't be more help.
     
  10. jasonsmf

    jasonsmf Active Member

    Jun 12, 2009
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    Just an update for anyone who's keeping score at home:
    The car has been running just fine, SES light has remained off. I've been occasionally scanning the codes to check on everything. Nothing pending, although the P0326 had remained stored (not active). I decided NOT to clear the codes, and continued to drive normally; just to see if the code would purge itself from memory. I am happy to report that after enough start cycles without tripping the P0326 again, it has cleared itself from memory and no codes are stored, pending, or active. Looks like the source of my SES light may have actually been the faulty muffler/vibration. Thanks for all the advice.

    Jason
     
  11. Crashton

    Crashton Club Coordinator

    Jun 4, 2009
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    Self healing MINIs what a brilliant car we drive.

    Glad it is going well for you Jason. :Thumbsup:
     
  12. quikmni

    quikmni Moderator

    Jun 6, 2009
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    I know that at least on my V8 Camaro the exhaust could affect the knock sensor. When changing to a header I also had to change the knock sensor module so that the sensor was less sensitive to the increased exhaust noise.
     

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