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Unknown engine noise help

Discussion in 'Engine & Performance' started by 78C10BigTen, Dec 4, 2019.

  1. 78C10BigTen

    78C10BigTen Full Access Member

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    Ok so this noise has been in this engine most of the time ive had it, this vid seems to be its loudest so far. It sounds rotational to me but idk. Its at the front of the engine, can anyone help me nail this down?? Its super friggin annoying!!!!

     
  2. Blue Ox

    Blue Ox Turning Diesel Fuel Into Fun

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    Sounds like a bearing on something is on it's way out.

    Best diagnostic technique I can think of is a long screwdriver against the accessories like the alternator, A/C compressor, water pump etc. and against your ear. You'll hear it distinctly when you're on the bad component.

    ***Obviously, (I hope) be careful not to get it in the belts or fan or whatever moving parts.
     
  3. 78C10BigTen

    78C10BigTen Full Access Member

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    I think i may pull all the belts off and start it for a minute to isolate engine or acc.
     
  4. Snoots

    Snoots Supporting Member Supporting Member

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    My money's on an alternator bearing.
     
  5. 78C10BigTen

    78C10BigTen Full Access Member

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    That would suck... its not that old
     
  6. dvdswan

    dvdswan Full Access Member

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    Could be the water pump. But being that loud you could pull the belts off and spin each item. Another thought if its been doing this for a long time even before replacing the alt, you could have sagging motor mounts and the fan is hitting the fan shroud.
     
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  7. 78C10BigTen

    78C10BigTen Full Access Member

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    Another overlooked possibility
     
  8. 78C10BigTen

    78C10BigTen Full Access Member

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    Quick visual inspection its not the fan.

    20191205_101320.jpg

    20191205_101327.jpg
     
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  9. QBuff02

    QBuff02 I like Big Blocks and I cannot lie

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  10. 78C10BigTen

    78C10BigTen Full Access Member

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    Ive never messed with it... always been that way. Truck never goes past 210 so cant be too bad
     
  11. Charlie

    Charlie Mopar by Birth. Chevy by Choice.

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    This is what I would try myself. Easier than removing belts to investigate. If no satisfying results, then belt removal would be next. Alternator bearings can be very loud. A wooden yardstick is good to use also. Good luck
     
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  12. dvdswan

    dvdswan Full Access Member

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    It depends on if the vehicle had a serpentine belt or v-belt. Serp belts rotate the w/p in the other direction. It looks correct just a smaller fan. I thought there was like a 1/2" clearance to the edge of the fan shroud. Looks like he has an inch or so.

    Aside from that, it may be a 4wd issue, but doesn't the crank pulley come close to the engine crossmember. I maybe thinking of another type of vehicle though. Your noise is a grinding noise so I'm trying to think outside the box other than a bearing.
     
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  13. 78C10BigTen

    78C10BigTen Full Access Member

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    So as i sit here in the running truck on my break at work, it made a liar outta me. Its not doing it now. Maybe it needs to be fully warm to expose itself...:shrug:
     
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  14. 82sbshortbed

    82sbshortbed Full Access Member

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    Problem solved. Lol

    Just kidding. Maybe the bearings need to wa rm up before they start making noise.
     
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  15. HotRodPC

    HotRodPC Administrator Staff Member

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    Last edited: Dec 5, 2019
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