99 355 hot manifolds | FerrariChat

99 355 hot manifolds

Discussion in 'Technical Q&A' started by 355f, Jan 18, 2004.

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  1. 355f

    355f Formula Junior

    Nov 1, 2003
    ok! expertise required here!.

    Car runs fine and I replaced the standard manifolds with tubi ones some time ago.

    After returning from a hard run this evening I opened the hood to check and both manifolds were glowing a bit - which is normal if you look in the dark but the left hand manifold ( as you look at the engine) seemed more red than the other.

    This could be due to different airflow over each side of course.

    Any views at all?? car runs fun, does not run hot, no check lights!!!
  2. ART360

    ART360 Guest

    Check your CATs. I'd bet you that their plugged. That problem cost me my manifolds on my 355.

  3. rketex7

    rketex7 Formula Junior

    Jan 8, 2004
    Full Name:

    Where did you get your Tubi headers? I am looking to get one in the future when I finally find the right F355. If they were replaced once by the dealer, would they still creak? I read they replaced the old ones with the newer design, is it true?


  4. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    If one header is visibly hotter than the other, I would suspect leanness in the mixture on the hotter bank of cylinders. If this proves to be the case, I would look at the oxygen sensor and thermocouple.
  5. malibumk

    malibumk Karting

    May 14, 2002
    Malibu, CA
    Full Name:
    Mike Klein
    I agree with Mitch, I've never heard of plugged Cat's but if so, something big is wrong upstream. Exaust temperature is a key indication of engine operation, and too hot is destructive in a big hurry. Need to plug an exaust gas analyzer in upstream of the cat's ....the OE headers have a port (don't know about the tubi's) and take it from there. Either the red hot one is too hot, or the cool one is running poorly (rich?) and may foul the cat. Either way your on the way to big $$ expenses if you run it much....I would not drive it beyond a few miles max...and very easy at that.

    I've heard of fuel injectors stuck open....but then one header pipe ought to show very hot...not all 4 on a side. Also have heard of a cold start injector failing open and frying the cat. Alternaively, the cold side may not be getting enough fuel...or.....

    Please let us know what you learn...very interesting problem.

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