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Noise after belt and tensioner bearing change

Discussion in '308/328' started by Doug, Nov 5, 2009.

  1. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
    Louisville KY
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    Doug
    Just completed a belt and tensioner bearing change on my 308. Everything was lined up TDC before removal and confirmed nothing had moved after installation of new belts and tensioner bearings. Turned the motor by hand for tension adjustment and a few more turns to make sure everything lined up again at TDC. All seems well so I buttoned everything back up. Started it up without problem, but I have a loud clacking or knocking noise that coincides with RPM.
    It is hard to tell exactly where the noise is coming from so I pulled the alternator/WP belt and the noise still happens. I pulled the AC and left it off completely during the change so that does not factor in. Turned the motor by hand again and everything still lines up on the flywheel and the rear cam mark through the oil fill. Pulled the belt covers off so I could see everything and re-adjusted the tension and the noise continues so I called it a day. I have not let the car run for more than 45 second and have not revved it above 1500 rpm. Am I being too cautious and it needs to run to settle in, or does it sounds as though some damage has already been done?
     
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  3. yelcab

    yelcab F1 World Champ
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    Nov 29, 2001
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    That is not normal Todd. It does not need to break in.

    I would get somebody to start the car while you watch the engine from the wheel well to see what is making that noise and go from there,
     
  4. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
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    I have started it and looked while it ran. Saw nothing that looked to be making any noise with the covers pulled.
    Forgot to mention that the car is a 2v motor 1977.
     
  5. AZDoug

    AZDoug Formula 3

    Jun 17, 2009
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    Are you SURE a cam didn't slip and now you are getting piston/valve contact?

    Do you still have the noise with the belt covers removed? If so,

    I would suggest you go down to pep Boys or Autozone or any other FLAPS and buy a mechanics stethoscope, the one with the long needle probe.

    Put the needle probe on the tensioner bearing axle bolts and listen, put the probe on each head end surface and listen.

    You can't put it on a rotating part, but put is as close as possible to the rotating part.

    You will hear the noise no matter where you put the probe, but when you find the place the noise is coming from, you will know it. Very good for locating bad roller bearings also.

    An 18" piece of 3/8" fuel line stuck in the ear works OK also, but is not as definitive, but has an advantage when listening to rotating parts.

    Doug
     
  6. BillyD

    BillyD Formula 3
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  8. Artvonne

    Artvonne F1 Veteran

    Oct 29, 2004
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    If its a valve whacking a piston, its probably too late. But I wouldn't run it anymore until you determine the cause by carefully checking it out. Pull the front cam cover and check your marks.

    If they are dead on, you'll need to look further.
     
  9. Doug

    Doug Formula 3

    Nov 13, 2003
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    I don't know how to be sure it didn't slip. Pulleys and old belts were marked with liquid ink before removal. Counted teeth and marked new belts before install and everything lined up. Double checked TDC at flywheel and on rear cam. Turned motor by hand to get tensioners set. Turned a few more times and checked to make sure all lined up at TDC. Everything looked good so I fired it right up. If something moved, it could not have been more than 1 deg otherwise the flywheel mark would be way off.
    I didn't hear any clanks or clunks or bangs. Just had the noise that follows the RPM. Thought it could be something with the alt. or WP so I removed the belt and the noise remained. Removed the belt covers thinking something may be hitting them and it still is there....
     
  10. Doug

    Doug Formula 3

    Nov 13, 2003
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    #8 Doug, Nov 5, 2009
    Last edited: Nov 5, 2009
    BillyD, did the bearings solve the issue at all? The thread had no outcome with the bearings, just the mechanic saying it is normal. The sound in the video is similar. I will get at it again tomorrow. Need a beer or two now.
     
  11. ulf308qv

    ulf308qv Karting

    Nov 1, 2003
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    Ulf M
    V-belts are a known source of clattering noise on 308´s. Did you install new ones?
    I used to have the same issue on my car during cold start. If you have confirmed that the camshafts are in the correct orientation, try to spray some WD40 or similar on the v-belts.
     
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  13. AZDoug

    AZDoug Formula 3

    Jun 17, 2009
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    Stethoscope will locate bad bearings real quick, tensioner or cam drive bearings. Place probe on case next to cam drive bearing. Slight valve contact would most likely sound like lots of little hits,and your car would probably start idling poorly.

    Good luck.

    Doug
     
  14. Doug

    Doug Formula 3

    Nov 13, 2003
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    I removed the alt./WP V-belt to eliminate that as a culprit and the noise was still there.
     
  15. rolindsay

    rolindsay Formula 3

    Jul 14, 2006
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    This should be checked. My 308 makes a snapping noise when cold. Its because of an overtightened v-belt. I'll replace everything and adjust it correctly when I do the minor on my 308. The WD40 blast is a good test. I use it any time my car is making too much belt noise.
     
  16. BillyD

    BillyD Formula 3
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    Carlo the Ferrari expert said it was fine, I put the car together & have been driving the hell out of it every since. I would verify there's no slop in cam drive bearings tho. Lots of threads on bad bearings here, mine sounded the same b4 & after the bearing change but I had no leakage or slop b4 changing.

    Bill
     
  17. Doug

    Doug Formula 3

    Nov 13, 2003
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    It appears that the noise is coming from the front cam drive bearing so I ordered up a pair. I removed the belt and there is some play in it. Unfortunately, I was rather hasty in pulling off my brand new tensioner bearing and learned quickly that they do come apart easily:(
    So I have ordered up a new tension bearing and new outer cam drive bearings and seals.

    The bearing noise sounded like BillyD's you tube video in the above link.

    How do you loosen the nut that holds the cam drive. Any source for a non Ferrari tool?
     
  18. yelcab

    yelcab F1 World Champ
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    Nov 29, 2001
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    Baum tool. $100. Don't try it without the tool. Don't try to make one. This is not one to cheap out.
     

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