My 348 engine is out (pics) and a rattle question. | FerrariChat
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My 348 engine is out (pics) and a rattle question.

Discussion in '348/355' started by sspooner, May 26, 2008.

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  1. sspooner

    sspooner Karting

    Jan 14, 2007
    165
    Sunnyvale, CA
    Full Name:
    Simon
    #1 sspooner, May 26, 2008
    Last edited by a moderator: Sep 7, 2017
    My 30k service is nicely underway. The engine is out.
    The timing belt looks in pretty good condition. The alternator belt on the other hand was pretty much shot.
    The valve covers and plenum are obviously missing as we took those off early to get them powder coated.

    :)

    Can't wait to get the ol' girl back together and on the road.

    We do have one worry though. before it went in for the service we have a rattle at engine start that appeared to be coming from very close to the tensioner bearing on the "passenger" side of the engine.

    It sounds like a sloppy valve, but we checked the valve area with a stethoscope and it definitely seems to be coming from further back, not the valve area, but close to the tensioner (very difficult to tell while the engine is in place). We suspect tensioner bearing spring since the belt does seem a tad on the loose side.

    I also suggested (after reading about it here) to the mechanic that we also check the oil pump chain while we've got it out since neither of us want it to go back in with the rattle still present.

    The odd thing about the rattle is that it starts about 30 seconds after a cold start and stays rattling for only a few minutes (3 or 4) and then you won't hear it again all day until you leave the car overnight and cold-start again. It's very heat sensitive.

    Anyone ever experienced this kind of rattle ?

    It's not the "pebble in a can" sound of the oil pump chain guides, but a much more subtle "tink tink tink tink" sound.

    Anyway, here's some pics.
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  2. Lars_vet

    Lars_vet Formula Junior

    Feb 25, 2007
    603
    On the open road
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    Lars
    #2 Lars_vet, May 26, 2008
    Dosent sound like oil pump tensioner...

    How do you like your Cappy exhaust, what level?
     
  3. sspooner

    sspooner Karting

    Jan 14, 2007
    165
    Sunnyvale, CA
    Full Name:
    Simon
    #3 sspooner, May 26, 2008
    Yeah, I think the oil pump chain problem would be a much louder, continuous problem. Mine goes away after a couple of minutes warm up.

    It's sporting a cappy 2 and hyperflows.

    :)

    I love the sound ! It's very loud but just sounds amazing, it really screams at the high RPM's.
     
  4. FandLcars

    FandLcars F1 Rookie

    Aug 6, 2006
    3,057
    Tempe, Az
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    Rick Schumm
    #4 FandLcars, May 26, 2008
    Last edited by a moderator: Sep 7, 2017
    This sounds a lot like the rattle I heard on my 348. I found that it was the exhaust air injection system. This system works when cold to inject air into the exhaust for a few minutes to reduce emissions until the engine (coolant) warms up some. Other Fchat members seemed to say theirs didn't rattle, but mine made a very un-Ferrari-like racket. I assumed the check valves in the system must be rattling.

    To test, while you're getting the rattles, just remove the vacuum hose connected to the shutoff valve on the system (see second closeup pic). The rattle should immediately stop, if that's the problem. Check both the left and right systems. Since my car is old enough that I don't have to get it emissions inspected, I just removed the system, and am going to plug the holes in the head.

    By the way.... our cars have a vacuum reservoir, and if the system also rattles a while as soon as you start the car when warm, it could mean you have a few minor vacuum leaks which may allow the reservoir vacuum to leak down when it sits. If you have good vacuum in the reservoir, the system should almost immediately shut off. These leaks may be fairly minor, though, but enough to allow the reservoir to leak down more quickly than if everything was pretty leakproof. Good luck with your car!
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  5. sspooner

    sspooner Karting

    Jan 14, 2007
    165
    Sunnyvale, CA
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    Simon
    #5 sspooner, May 26, 2008
    Thanks for the tip Rick. I'll check that out.
    How's your engine-out going ?
     
  6. FandLcars

    FandLcars F1 Rookie

    Aug 6, 2006
    3,057
    Tempe, Az
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    Rick Schumm
    #6 FandLcars, May 26, 2008
    Hope the info helps and that's all your problem is ;) I'm moving pretty slow on the engine-out, but everything's going pretty well. I'm not in a big hurry at all, although it's going to start getting hot here in Phoenix area. I'm updating a thread periodically (link below). Although I'm pretty comfortable working on it, it's still a learning experience at times.

    I just finished checking valve adjustment... will probably have to reshim 8 valves or so... none too far out of spec, though. Worst exhaust 0.015, worst intake 0.011. I'm now fabbing up a dial-indicator stand to allow me to measure piston TDC, and make a piston stop. Since I'm replacing all cam seals, I plan to take out cams. But first I'm also going to do my own leakdown test with a Moroso tester I got on Ebay. It was great during the PPI in January, but I want to get my own measurement for future reference.

    Good Luck!

    http://www.ferrarichat.com/forum/showthread.php?t=192646
     
  7. db4

    db4 Karting

    Oct 24, 2009
    94
    ny
    #7 db4, Nov 25, 2009
    1993 348ss just put my engine back in after 30k service , i have the same rattle at cold start
     
  8. ferrari 512 tr

    ferrari 512 tr F1 Rookie

    Nov 16, 2008
    4,181
    Australia
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    Paolo
    #8 ferrari 512 tr, Nov 26, 2009
    Last edited: Nov 26, 2009
    simon
    u reckon a stage 3 capristo would be too loud
    or should i go with a level 2 like yrs.
     
  9. sspooner

    sspooner Karting

    Jan 14, 2007
    165
    Sunnyvale, CA
    Full Name:
    Simon
    #9 sspooner, Nov 26, 2009
    Last edited by a moderator: Sep 7, 2017
    Mine turned out to the be the oil chain tensioner. It would rattle for about 10 mins during warm up and sounded terrible.

    We hunted for it for a while and when we dropped the bottom pan and got the front off we saw the attached pic. We installed new tensioners and I don't get the rattle any more

    :)
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  10. sspooner

    sspooner Karting

    Jan 14, 2007
    165
    Sunnyvale, CA
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    Simon
    #10 sspooner, Nov 26, 2009
    Oh man, I'm so glad I went with 2 and not 3.

    :)

    Don't get me wrong, I LOVE them loud, but I think a 3 would have been too loud for me.
    My "2" has already drawn attention from the local cops. None have done anything yet, but they are definitely curious about it. My local indy who installed it asks me frequently if I've been busted for it yet. He's convinced it's just a matter of time. :)
     
  11. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
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    #11 ernie, Nov 26, 2009
    Thanks for the update Simon, and I'm glad to know you fixed it.
     

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