355 valve issue | FerrariChat

355 valve issue

Discussion in 'Technical Q&A' started by feliciano, Mar 27, 2007.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. feliciano

    feliciano Karting

    Mar 18, 2006
    89
    Monterrey
    Full Name:
    Feliciano D. Molina
    Does anyone know the symptoms when a valve in a 355 is bad? Is this the cause of backfires?

    Thanks!
     
  2. Darolls

    Darolls F1 Veteran
    BANNED

    Jul 2, 2003
    7,782
    Full Name:
    Sparky
    It can be, but the real issues with the 355 were the valve guides, not the valves.
     
  3. Intheflesh

    Intheflesh Formula 3

    Jun 2, 2006
    1,180
    Salem NH
    Full Name:
    John T
    i believe blue-ish exhaust smoke was a symptom
     
  4. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    18,054
    USA
    High oil consumption is another hallmark of bad valve guides.
     
  5. Darolls

    Darolls F1 Veteran
    BANNED

    Jul 2, 2003
    7,782
    Full Name:
    Sparky
    If the condition is due to the valve guides, and the guides drop, you've got a major problem and expense.

    Best to have the problem checked by a pro!
     
  6. nunojcmaia

    nunojcmaia Formula Junior

    Dec 16, 2004
    389
    porto - portugal
    Full Name:
    nuno maia
    Is there anything we can do on a 355 to prevent the so talked valve guide issues?
    My car has not had any troublesome till today, has not high oil consumption neither blue-ish exhaust smoke or any other symptom.
    Changing oil more frequently or driving at lower speed (please say NO!!!) has anything to do with that?
     
  7. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    18,054
    USA

    Yes, stop driving the car.
     
  8. Bobert

    Bobert Formula Junior

    Jan 17, 2004
    277
    Oak Hill VA
    Mine (98 GTS) had absolutely no symptoms....except for exhaust header problem...took it in for the major...

    after that u reacha inna you wallett...you taka out alotta money...you give it to a good repair man...you getta you car back. Itta will runna reel good after dat!
     
  9. feliciano

    feliciano Karting

    Mar 18, 2006
    89
    Monterrey
    Full Name:
    Feliciano D. Molina
    I am posting a new thread with photos under the title: 355 BACKFIRES MISTERY SOLVED.

    Like some might have noticed, I have been posting threads for almost a year on backfires with no precise answers about the cause. Many pointed air leaks, too rich on the mix, manifolds cracked (most popular) and although I really appreciate everyone´s input, I have to give the credit to Daniel at Ricambi and the Guys at Weber Automundo, in Monterrey Mexico.

    I had made my mind up about getting new manifolds (which I will but not right now) with new cats (which I AM getting -Hyperflows) and called Daniel at Ricambi, after doing some shopping arround. The reason I want to give this man credit is because instead of jumping into selling me manifolds right away, he was genuinely interested in getting the facts and symptoms over the phone. He then suggested that backfires could be related to the bypass valve or vaccum guides, not precisely manifolds cracking. That although 355´s in fact go bad on headers, the symtoms are more "tapping noises" than back fires.

    I took the car to Weber automundo where they noticed the valve hose been worn out and the vaccum guide to be almost broken. They had to take the valve appart and revise it. The mechanic sucked on the pipe to see if it wasn´t getting stuck, and found out it was ok. He then put a new guide (it goes from the bypass valve to a selenoid connector on the passanger side) and a temporary hose to see if the backfires stopped. We left the car iddling for an hour until it got really warm and then drove it with "enjundia" (that´s spanish slang for "intense"). The result: backfires are gone!

    Hope this thread helps other 355 owner´s when dealing with backfires that only occur on decelleration and when car gets hot.

    PD. The hose has to be high temeperature resistant, others won´t last much (days maybe) and it can make one there is another problem.

    Good luck.
    Feliciano
     
  10. Darolls

    Darolls F1 Veteran
    BANNED

    Jul 2, 2003
    7,782
    Full Name:
    Sparky
    Looks like you lucked out. :)

    There's no better diagnosis than hands on.

    Glad the problem is fixed.
     
  11. delaney

    delaney Formula Junior

    Nov 8, 2003
    721
    Montgomery TX
    Full Name:
    PETER DELANEY
    I'm no mechanic but I don't think dropping a valve is associated with bad valve guides. Bad valve guides just consume oil...drop oil into the cylinders and then foul the plugs and may screw up the catalytic converters.

    As Dave H says ..you can avoid the problems with the valve guides by .... only...stopping driving the car ...sorry!

    Again..I'm no mechanic ..just thinking logically.


    Pete
     
  12. Darolls

    Darolls F1 Veteran
    BANNED

    Jul 2, 2003
    7,782
    Full Name:
    Sparky
    My tech has a 355 in the shop right now where the valves 'grew', due to bad guides, and the car was run hard.

    Result; valves kissed the pistons, bent valves and a big ticket!
     

Share This Page