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355 questions

Discussion in '348/355' started by TomF, May 15, 2006.

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  1. TomF

    TomF Rookie

    Feb 21, 2006
    22
    Cardiff UK
    Full Name:
    Tom Good
    This is probably a really silly question but after shutting down my 1998 355 after a run, I've noticed a motor-like whine coming from the engine - it sounds like a pump motor and I've only heared it as the engine is cooling down. I've only had the car a couple of months so forgive my ignorance.

    I've also noted a buzzing sound from the car bay at idle and around 2,700 rpm - I assume this is the bypass valve. My question is has anyone fitted the Kreissieg bypass-valve and thought it a good replacement? I know you can wire the valve open or fit a Ferrari part but would like to keep the car stock but with a better replacement part if poss.

    Thanks for your advice.

    Tom
     
  2. edmo7

    edmo7 Formula Junior

    Jul 8, 2004
    280
    Irvine, CA
    Full Name:
    Ed
    To answer the Kriessieg bypass valve question: Kreissieg only sells their bypass valve along with their exhaust system. However, Kreissieg does carry a PIPE that replaces the secondary cats which lead to the factory bypass valve.
     
  3. FL 355

    FL 355 Formula 3

    Nov 3, 2002
    1,665
    Ft Laud
    Full Name:
    Frank Lipinski
    I think Tubi may make a by pass hollow tube also. However, I don't think it's the problem. Normally, when they go bad they make more of clanging rather than a buz. (real techno terms here).

    Typically, before they go bad you can here it on cold start banging around. Actually, it will bang until the temp comes up, expands the metal then it noise will go away. You can temp. wire it open and see if the noise is still here and go through the process of elimination. The only buz I'm aware of is the air pump on cold start will "buz" until warm up. If you do a cold start and stand at the back of the car the pump noise comes from the right corner next to the tail lights.

    I also never experienced a motor like sound on shut down... Is the noise similar to that if you turn the key on without spinning the motor? I'm referring to the ecu and fuel pump cycling up....? And the engine is completely off, right?
     
  4. CarCrazy

    CarCrazy Karting

    Oct 2, 2004
    104
    Douglassville, PA
    Full Name:
    Bob
    Do you have 6 spd or F1 ?? I have '99 355 GTS1. You may be hearing F1 pump priming on startup. Can't say anymore in regards to F1 pump / relay problems vs exhaust unless one knows what kind of tranny you have.
     
  5. TomF

    TomF Rookie

    Feb 21, 2006
    22
    Cardiff UK
    Full Name:
    Tom Good
    Thanks for the replies.

    What I thought was the valve noise isn't a clatter its more of a buzzing sound so perhaps its just something on the rear deck lid. I'll wire the valave open as you suggest and check it out. Thanks for the tip.

    The car has an F1 gearbox
    I only hear the motor sound once the engine has been shut off. It could be present whilst the engine is running - but I wouldn't hear it because its high pitched. After a minute or so after shut down, the sound comes on for about 30 sec then a pause for another minute or two and then once again the motoric sound starts up for 30sec and then that's it - all quiet.

    I just wondered whether it was something to do with the fuel system - perhaps relieving pressure in the system once the engine has been shut down?

    I don't think (hope) its anything serious - I just wanted to understand what the car was doing as I'm a total 355 rookie.

    Thanks for any advice.

    Tom
     
  6. chrisx666

    chrisx666 Formula Junior

    Dec 6, 2004
    562
    YorkshireUK
    Full Name:
    Chris B
  7. TomF

    TomF Rookie

    Feb 21, 2006
    22
    Cardiff UK
    Full Name:
    Tom Good
    Yup that sounds like the motor sound I'm getting. Thought it might be related to the fuel system. Not sure about a cow tho - more like the whining noise I get from my 8-year old on being told its bed time.

    Thanks very much for spotting the link.

    Regards

    Tom
     
  8. davehelms

    davehelms F1 Rookie

    Jan 3, 2004
    4,629
    Full Name:
    Dave Helms
    Coolant cap venting or the carbon canister venting the fuel tank from heat expansion

    Dave
     
  9. jaydens1

    jaydens1 Rookie

    May 17, 2006
    33
    new zealand
    Full Name:
    tony j downes
    on shutdown try depressing the accellerator lightly.if it alters it could be just atmospheric air filling the vacuum in the manifold past idle control valve
     
  10. jaydens1

    jaydens1 Rookie

    May 17, 2006
    33
    new zealand
    Full Name:
    tony j downes
    can anyone recommend oils i should use in the motor and f1 transmission
    have been told shell helix 5w40 synthetic and spirax synthetic.mobil1 5w40?
     

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