Timing Belt Tension (or lack thereof) | FerrariChat
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Timing Belt Tension (or lack thereof)

Discussion in '308/328' started by David Lind, May 4, 2016.

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  1. David Lind

    David Lind Formula 3

    Nov 19, 2008
    2,248
    Full Name:
    David Lind
    #1 David Lind, May 4, 2016
    Last edited by a moderator: Sep 7, 2017
    I have as Mondial 3.2, & yesterday I was looking over all the accessory drive belts. Through the small opening (about 2 inches) which allows access (see center of attached photo) to the front bank timing belt I could feel that the belt was quite slack. It was really to the point of worrying about it. Nevertheless, I started the car & let it idle for 30 seconds. I shut off the engine, checked the belt tension, & it was quite tight. Is this normal to have the tension seemingly change within a 30 second span?
    BTW: From a time perspective, although not from a mileage perspective, I am very much past the due date for belts and tensioners.
    Any thoughts? Thanks!
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  2. Brian Harper

    Brian Harper F1 Rookie
    Owner Silver Subscribed

    Feb 17, 2006
    4,078
    San Jose area
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    Brian Harper
    #2 Brian Harper, May 4, 2016
    The valve springs acting on the cam lobes will make that run of belt tighter or looser depending on where the cam stopped. So that's normal. But how loose or how tight should it be? I'll let others comment on that.
     
  3. Squirrelmonkey

    Squirrelmonkey Karting

    Dec 27, 2010
    126
    Manitoba ,Canada
    Full Name:
    Tom Thieme
    #3 Squirrelmonkey, May 4, 2016
    The springs on the tensioner is ALL that is required to set cam belt tension. once the engine is rotated at least once to ensure there is no backlash in the oil pump/timing gears.
    You then lock the tensioners by tightening the nuts. some people chose to tension these belts like guitar strings !!!! That will cause roller bearing failures and cam journal wear..
     
  4. David Lind

    David Lind Formula 3

    Nov 19, 2008
    2,248
    Full Name:
    David Lind
    #4 David Lind, May 5, 2016
    Thanks!
     
  5. scowman

    scowman F1 Rookie

    Mar 25, 2014
    2,550
    Scottsdale AZ
    Full Name:
    Stu Boogie
    #5 scowman, May 5, 2016
    Change your belts and tensioners. Check your lower cam pulley bearings and cam pulleys at the same time. Consider changing the water pump and rebuilding your alternator as they are easy access at that time.
     

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