High pitched chirp/fluttering sound - 355 | FerrariChat
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High pitched chirp/fluttering sound - 355

Discussion in '348/355' started by TrojanFan, Nov 9, 2015.

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  1. TrojanFan

    TrojanFan F1 Veteran
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    #1 TrojanFan, Nov 9, 2015
    Anyone have any thoughts on a potential cause of a high pitched chirp/fluttering sound that's coming from the left rear of the engine compartment? Almost sounds like it's coming from the area of the left CAT.

    CAT was replaced about 18 months ago with a Fabspeed re-core of the OME and recently tested good so I don't think it's that unless something came lose inside and is vibrating.

    Anything else in that area subject to vibration that would make a high pitched chirp/fluttering sound? My bypass valve is bad but I was hearing this after I isolated that from the mix.

    Thanks
     
  2. emac

    emac Formula Junior
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    #2 emac, Nov 9, 2015
    Take a piece of hose and put it to your ear and move the hose around the engine compartment and try to figure out where it is coming from. They make auto stethoscopes
    but the hose will work.
     
  3. plugzit

    plugzit F1 Veteran
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    #3 plugzit, Nov 9, 2015
    Throwout bearings sometimes chirp. Does it dechirpify (that's a scientific term) when you depress the clutch? If it does, you need to perform a dechirpification procedure (medical terminology). As a point of interest, a dechirpification procedure was first performed by Dr. Dechirp Pakra, cousin of the famous motivation doctor Deepak Chopra.
     
  4. bcwawright

    bcwawright F1 Veteran

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    #4 bcwawright, Nov 9, 2015

    could be DePrairie Doggin gone depuckin(Dr BS terminology)
     
  5. KM1959

    KM1959 Formula Junior

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    #5 KM1959, Nov 9, 2015
    Without hearing it it is nearly impossible to diagnose but I've had blown header gaskets sound like your description. Hopefully it's not a header issue.
     
  6. ///Mike

    ///Mike F1 Veteran

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    #6 ///Mike, Nov 10, 2015
    Leak in the air injection system for the exhaust?
     
  7. Robbe

    Robbe Formula Junior
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    #7 Robbe, Nov 10, 2015
    as there are no belts or bearings on the left rear, I would think air injection as well.
    Or maybe the airco pump belt, which sits on the front left, but the sound travels to the back?
    The air injection system travels all the way to the right rear, but has not too many connection points on the left. So best start there.
     
  8. watkinsgt

    watkinsgt Karting

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    #8 watkinsgt, Nov 10, 2015
    My flutter sounded like it was immediately behind my left shoulder. Never could track it down and of course the car never exhibited the symptom at the dealership. However, as a precaution I replaced the OEM headers with stainless and haven't heard it since. So maybe a header gasket.
     
  9. yelcab

    yelcab F1 World Champ
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    #9 yelcab, Nov 10, 2015
    Get a hose, stick it in your ear, go fish.
     
  10. Shorn355

    Shorn355 F1 Veteran
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    #10 Shorn355, Nov 10, 2015
    Are you running the stock muffler? Mine had what seems comparable to the sound you are describing and it was the factory muffler starting to delaminate. Only occurred at certain RPMs but unfortunately right at the RPM for parking/maneuvering and dawdling in traffic so a bit embarassing and annoying. Replaced factory muffler with Capristo and sound is gone.

    Just something to check out - Good luck - Cheers :)
     
  11. TrojanFan

    TrojanFan F1 Veteran
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    #11 TrojanFan, Nov 10, 2015
    Stock exhaust except for the CATS. Before I replaced the CATS, one of them was completely blown out. There may be parts left in the muffler that are vibrating.
     
  12. Shorn355

    Shorn355 F1 Veteran
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    #12 Shorn355, Nov 11, 2015
    That was exactly what the FoD guys found when they stethed it so might be your culprit. I would have someone (or you) steth it and see. New factory muffler slightly cheaper than Capristo but weighs a lot more and IMHO does not sound as good. Tubi also the normal option but like the Capristo better on the 355 - Tubi a bit high-end pitch for me. All a matter of preference though.

    If is is indeed the original muffler I imagine it is or will be soon delaminating so probably something to budget for even if it is not the source of your annoying noise.

    Cheers and good luck :)
     

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