metal rattle around 2000rpm or kicking the exhaust? | FerrariChat
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metal rattle around 2000rpm or kicking the exhaust?

Discussion in '348/355' started by bigpino, Feb 12, 2010.

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  1. bigpino

    bigpino Rookie

    Nov 4, 2009
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    Pino
    #1 bigpino, Feb 12, 2010
    Yet another tiny issue I hope.

    The 'metal' rattle is reasonably loud since one can hear it inside the car. The main resonance is around 2000rpm. At a stand still and motor off you can actually hear something bashing back and forth several times when you kick the exhaust. Yes, I said that, just like sokker.

    I also read something about a loose bypass valve could do that, but that tread was about 355s. Any idea and if so how to check?
     
  2. striker27

    striker27 Karting

    Feb 22, 2008
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    andy
    #2 striker27, Feb 12, 2010
    Last edited: Feb 12, 2010
    It may be the catalytic converter has become damaged and some pieces have broken off inside.....

    Try tapping it..

    It could also be a simple as a heat shield......


    It may also be simple like a heat shield rattling...
     
  3. bigpino

    bigpino Rookie

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    #3 bigpino, Feb 12, 2010
    I'll try tapping the cat, but really I kicked the exhaust with no effort. The piece that moves sounds as if it's too big to fit in a cat. Or are you saying that it is very uncommon that the exhaust does that?
     
  4. bigpino

    bigpino Rookie

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    #4 bigpino, Feb 12, 2010
    Dont mind this message. It's to test the new notification setting.
     
  5. FerrariDeeJay

    FerrariDeeJay Formula Junior

    Jun 2, 2009
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    Michael
    #5 FerrariDeeJay, Feb 12, 2010
    My muffler started to rattle also. It had a lot of the catalytic converter material inside of it, almost all of it, since my cat was empty when it was removed for replacement at 30k miles. I had to remove the exhaust and shake it out to remove it-then no more rattle.
     
  6. Miltonian

    Miltonian F1 Veteran

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    #6 Miltonian, Feb 12, 2010
    It's possible that the entire matrix inside the converter is moving around inside the housing. That's what happened on mine. It could move about 1/8" back and forth, and was totally detached, but didn't seem to have anything wrong with it otherwise. I drilled and tapped a hole in the housing, and installed a threaded screw to hold it tight in place. Worked fine.

    I also had a tab snap off the tail pipe right where it exits the lower muffler, and that caused a loud rattle. It just made a new tab here at home and clamped it onto the pipe. Easy fix.
     
  7. bigpino

    bigpino Rookie

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    #7 bigpino, Feb 12, 2010
    interesting, possible causes ranges from a complete shattered cat to something that can be fixed with screw driver:). Knowing my luck, it will be more on the costly side of the spectrum.

    Thanks for the replies. now I got a better overview of the possibilties. One more question: Can the exhaust be removed without detaching the bumper? And the cat without disasemble half the motor?
     
  8. INTMD8

    INTMD8 F1 Veteran
    Owner Silver Subscribed

    Jun 10, 2007
    6,683
    Lake Villa IL
    #8 INTMD8, Feb 12, 2010
    Not sure if about the exhaust/bumper question but the cats are fairly easy to remove.
     
  9. rbellezza

    rbellezza F1 Rookie

    Jun 18, 2008
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    Roberto Bellezza
    #9 rbellezza, Feb 12, 2010
    I had a similar issue on my Porsche and they ended up being the cats .... good excuse to go for High Flows ....
     
  10. BLAMPEE

    BLAMPEE Man Card Status: Never Issued

    Jun 28, 2008
    15,424
    Sunny Heavenly Beautiful Arizona
    #10 BLAMPEE, Feb 12, 2010
    Same thing for me in my 355. The left cat had completely disinigrated. So, during my 30k I had to replace the exhaust because my mechanic showed me what the inside of the OEM muffler looked like--there are like 8 baffles, which means that those pieces could not be shaken out nor would they likely come out on their own any time soon.

    Ok, enough of this posting crap--I'm in Hawaii on vacation and I'm going down to the beach for the fireworks display.

    :):):) Mahalo! :):):)
     
  11. bigpino

    bigpino Rookie

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    #11 bigpino, Feb 13, 2010
    Last edited: Feb 13, 2010
    high flows, huh? I'll look into that:)

    blampee you basterd. Only post to let people know you have too much fun;) I understand you had to replace both cat and exhaust?

    I hoped it would be the exhaust, since it is hanging low. Like, if you look at the pipes relative to the bumper. it's down like 5cm or more. And the whole exhaust seems to hang a bit loose, but I saw some spring suspension and guessed it must be that.

    but then again, one slow down light comes on after relatively short high rev session. The light goes off in a very gradual manner. I thought it was a grounding issue.
     
  12. BLAMPEE

    BLAMPEE Man Card Status: Never Issued

    Jun 28, 2008
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    #12 BLAMPEE, Feb 13, 2010
    Yes, I'm having LOTS of fun--8:53am and I'm still lying in bed. ;)

    I had to replace both cats AND the exhaust muffler--I went with Quicksilver SuperSports because the price was less than half of a Tubi, Capristo, etc. The sound is amazing. I pit Hyper-Flow cats AND rebuilt headers from QV. Call Daniel @ Ricambi to get the best deal on the headers and/or cats. I bought the Quicksilver from an FChatter who sells them new. Let me know if you need his info. :)

    I'm off to have a relaxing nap at the beach now.

    :D
     
  13. ferrari 512 tr

    ferrari 512 tr F1 Rookie

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    #13 ferrari 512 tr, Feb 13, 2010
    well done son
    and also
    lucky you
     
  14. lindsey

    lindsey Karting

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    #14 lindsey, Feb 13, 2010
    Before you get to far ahead of your self take a long screw driver and put a little pressure on the lever of the exhaust by pass valve sometimes they go bad and will rattle at a low RPM I had this same problem.
     
  15. Loser

    Loser Formula Junior

    Apr 11, 2008
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    #15 Loser, Feb 14, 2010
    I had a rattle once that I thought might be the bypass valve, but it ended up being that one of the bolts that held the muffler in place had come loose. I tightened it and no more rattling.
     
  16. msa

    msa Rookie

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    #16 msa, Feb 16, 2010
    check the spring mounts for the exhaust when reving the engine, if it rattles alot at 2000 rpm that can be the source but not the problem. my exhaust was cracked in the L/H mount
    but the noise was from the spring assy so check for cracks. good luck
     
  17. bigpino

    bigpino Rookie

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    #17 bigpino, Feb 18, 2010
    Last edited: Feb 18, 2010
    So you're saying even if I hear something loose when kicking the exhaust (engine off), it can still be the bypass? Just for addition clarification: When I kick the exhaust tale pipe, I hear something going back and forth banging against metal. And it's relatively slow, so it got some mass. Differs on the temperature of the engine/exhaust. When cold it sound sturdy and when warm it sound very loose and takes a few seconds to stop.

    The whole concept of an exhaust bypass is new for me. Do you have a pic of it and can you point out where to put the screw driver? I looked at some pics, but can only find pics of the sole part. They're kind of expensive too!

    I noticed that the exhaust basically have two sections (upper and lower) that are suspended (spring bolted). The upper one is connected to the cats and the lower one. Are you referring to the bolts at the 'joints' or the 'bracket' as described below?

    By L/H mount, do you mean the 'bracket' that holds the whole exhaust inside the car? And what is a spring assy?

    I feel like a noob.
     
  18. Miltonian

    Miltonian F1 Veteran

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    #18 Miltonian, Feb 18, 2010
    I don't think your 348 has the bypass valve, isn't that just the 355?
     
  19. bigpino

    bigpino Rookie

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    #19 bigpino, Feb 19, 2010
    Currently it's not to cold so I had the chance to knock around and take a good look. It appears to be the heat shield of the cat on the inner side. Gonna put a metal strap on it for the time being and will make an 'appointment' with a welder later on. I guess I was lucky this time.

    Thank you guys, it's because of these kind of sites that it is worth it to take a risk and buy one;).

    Makes sense couldn't find any for the 348 so I thought it's all the same for the 355.
     
  20. Jeff Pintler

    Jeff Pintler Formula Junior

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    #20 Jeff Pintler, Feb 23, 2010
    I found two metal rings that hold the ceramic matrix in the 355 cats. The pieces can be cut apart by using an air powered cut-off wheel and slice along the seam of the two halves of the cat. The rings are 1/2" by 1/4" and you can weld right over the seam and it looks unmolested. Remember this is stainless. FWIW


    Jeff Pintler
    89 348tb, 86 tr, 99 360 3-pedal
     
  21. HMF

    HMF Rookie

    Feb 25, 2010
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    #21 HMF, Feb 25, 2010
    If its your cats are bad, I do have a set of metallic race cats forsale, carb approved
     

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