chirping noise - didn't improve with changing water pump/alternator belt | FerrariChat

chirping noise - didn't improve with changing water pump/alternator belt

Discussion in '206/246' started by rbsloan11, Dec 21, 2019.

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  1. rbsloan11

    rbsloan11 Karting

    Apr 25, 2007
    117
    Carmel
    Full Name:
    Rob
    I developed this noise after not using the car for a few months. It is fairly loud - did not resolve with changing the water pump belt. In person it sounds like an air leak? I found some fuel on the pan area below the intake but could not see new leakage with the engine running or sitting with the fuel pump on. I attached a video.

    Thanks,
    Rob

    watch
     
  2. TonyL

    TonyL F1 Rookie

    Sep 27, 2007
    3,811
    Norfolk - UK
    Full Name:
    Tony
    Sounds like it coming from the water pump side of the car, very similar to a metal to metal rubbing sound.

    I would remove the rear wheel (place a axle stand under the car chassis for safety) and start the car and try to dial in where the sound is coming from.

    Sounds like water pump, check if you have bearing play on the pulley, could be alternator pulley rubbing on something as well?

    Did you remove any pulleys when replacing the belt?
     
  3. dgt

    dgt Formula 3
    Owner Silver Subscribed

    Jan 14, 2011
    1,283
    Northeast, USA & Oz
    Full Name:
    Andrew
    Right, The oil hose for the heat exchanger runs past the alt pulley, might be touching?
    It has a metal braid outer sheath
     
  4. TonyL

    TonyL F1 Rookie

    Sep 27, 2007
    3,811
    Norfolk - UK
    Full Name:
    Tony
    Did you replace the "complete" water pump? if so then some of them dont have enough clearance using the old pulleys!
    Tony
     
  5. rbsloan11

    rbsloan11 Karting

    Apr 25, 2007
    117
    Carmel
    Full Name:
    Rob
    The sound started out before I replaced the belt. I thought it was the belt and started there. Same water pump/alternator and pulleys that never made the noise. This morning I took the belt off and started it and the noise is still there so not from the water pump, alternator or belt/pulleys. Could it be an exhaust leak?
     
  6. DinoLasse

    DinoLasse Formula Junior
    Silver Subscribed

    May 26, 2009
    598
    Sweden
    Full Name:
    Lars
    Yes, I think it could. The repetition rate of that chirping noise sounds like it could be an exhaust leak from one of the cylinders.
    Since it appears that you have a seemingly unmolested US version, you have the whole exhaust air injection system to take into account. One of the air injectors - if you still have them - could have developed a leak. If the injectors have been removed and replaced with a blocking plug, one of those plugs could be leaking.
    Well worth checking.
     
  7. rbsloan11

    rbsloan11 Karting

    Apr 25, 2007
    117
    Carmel
    Full Name:
    Rob
    Lars - Thanks for the advise. It still has the air injectors in place. I will check those next.

    Rob
     
  8. TonyL

    TonyL F1 Rookie

    Sep 27, 2007
    3,811
    Norfolk - UK
    Full Name:
    Tony
    Could be exhaust leak but doesnt sound like it to me!
    Surely with the belt off you can zero into where the sound is coming from?
    Distributor?
    Cams?
    Clutch?
     
  9. DinoLasse

    DinoLasse Formula Junior
    Silver Subscribed

    May 26, 2009
    598
    Sweden
    Full Name:
    Lars
    I agree that it sounds more like a mechanical rubbing sound, Tony. If so, from something that rotates fairly slowly, so distributor or cams (hope not!) are possibilities. But Rob said it sounded like a leak when you hear it in person, so well worth checking the exhaust manifold too. Yes, it seems like it should be possible to locate the area where it comes from. It is certainly loud enough.

    Rob, I hope you can track it down by following the sound, perhaps with the aid of a hose or tube as a stethoscope. And let us know what it was.

    Lars
     
  10. rbsloan11

    rbsloan11 Karting

    Apr 25, 2007
    117
    Carmel
    Full Name:
    Rob
    I finally figured out the source of the chirping noise. The passenger side carburetor insulation block (made of some type of phenolic material) had broken allowing air to pass thru a small defect. The gasket was fluttering and acting as a whistle. I ordered all new blocks, gaskets and o-rings this am.
     
    dgt likes this.
  11. racerboy9

    racerboy9 Formula 3
    Silver Subscribed

    Nov 3, 2003
    2,499
    It did sound like an intake leak to me but I've never seen those phenolic blocks break.
     
  12. npwmd2

    npwmd2 Karting

    Mar 31, 2015
    226
    Hudson Valley
    Full Name:
    Neal
    Hey Rob,
    Could you send a photo along of the crack, so we all can see for reference!
     
  13. rbsloan11

    rbsloan11 Karting

    Apr 25, 2007
    117
    Carmel
    Full Name:
    Rob
    Yes I will post some pictures. I am waiting for the new parts before taking things apart. A friend of a friend who is a great mechanic figured out with a stethoscope in a few minutes. He had a stethoscope with a bell shaped end unlike my cheap tube shaped one. The phenolic spacer broke into several pieces, one piece was sitting barely attached under the carb but angled outwards. I have no idea why that happened? I am glad it didn't go thru the intake but as it isn't metal I would hope it wouldn't have damaged anything. Maybe a super rare failure? - doesn't seem like anyone else has had this happen.
     
  14. rbsloan11

    rbsloan11 Karting

    Apr 25, 2007
    117
    Carmel
    Full Name:
    Rob
    Finally replaced the carburetor spacers (the other 2 were cracked but still intact), all new gaskets and o-rings. Problem fixed, car runs perfectly now. It had a hesitation and had been running a little rough for a while - this has all resolved. Here are a few pictures:
    View attachment 2904856 View attachment 2904857
     

    Attached Files:

    dgt and TonyL like this.
  15. Nuvolari

    Nuvolari F1 Veteran
    Owner Silver Subscribed

    Sep 3, 2002
    6,370
    Toronto / SoCal
    Full Name:
    Rob C.
    I had the exact same cracking take place. Carbs are to be tightened down very lightly. Over tightening will break the spacers and can warp the carbs.
     

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