455 noise. HELP !!!

Discussion in 'Street/strip 400/430/455' started by oldsbuick455, Jul 7, 2016.

  1. oldsbuick455

    oldsbuick455 Member

    First start of my '75 455 buick since a decade, everything went smooth and the engine started up immediately. 4 to 5 smooth and well start ups later in the last month, the engine started to make a noise. The guy I'm fixing my car at told me that it may be a loose connecting rod. Is it possible that after 5 smooth start ups, such a problem appears? What are your thoughts? If any one faced such a problem please tell me what have you done with your engine. And guys what are your suggestions? And what the problem may be from? The oil was changed before first start up. Thanks for your help.
     
  2. Mark Demko

    Mark Demko Well-Known Member

    What kind of noise, bearing knock?
    Whats your hot oil pressure?
    After 10 years or more of sitting, did you pull the distributor and spin the oil pump to make sure its still primed?
    Just blindly starting it after over 10 years of sitting without making sure the oil pump is primed is asking for trouble.
     
  3. oldsbuick455

    oldsbuick455 Member

    Well... done nothing of those. Only oil and spark plugs replacing. Haven't checked the oil pump. I don't think it's a bearing knock.
     
  4. knucklebusted

    knucklebusted Well-Known Member

    It would help to have a recording of the noises. Is it a deep metal on metal thud, a light hammer tapping, clack-clack or click-click? Does it go away with RPM, get worse with RPM? Comes from top of motor, bottom of motor, front of motor or back of motor?

    It could be anything from a loose torque converter to a noisy lifter/rocker or something in between. I'd put an oil pressure gauge on it and see what you have first.
     
  5. oldsbuick455

    oldsbuick455 Member

    I will upload a recording of the noise as soon as I can. The noise come from bottom of motor and get worse with RPM. It's a loud clack-clack. So what you think?
     
  6. Jim Rodgers

    Jim Rodgers Well-Known Member

    Sounds like #7 rod bearing. Oil Pump should have been filled with petrol jelly and engine primed before startup. Cut the filter open, the clues should be in there.
     
  7. knucklebusted

    knucklebusted Well-Known Member

    As much as it pains me, I'm afraid that's probably the noise based on his description and location.
     
  8. oldsbuick455

    oldsbuick455 Member

    The problem source is found. It was the timing chain that was a bit damaged and loose. I will replace it and watch for the oil pump.
     
  9. Jim Rodgers

    Jim Rodgers Well-Known Member

    Great news!!! Keep us posted.
     

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