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Knocking Sound near water pump???

Discussion in 'The Garage' started by erin3183, Feb 13, 2004.

  1. erin3183

    erin3183 Registered Member

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    Hi, I have an '89 chevy 4x4 with a 305. I wanted to know what might be causing an irregular(no pattern to this knock, totally random) knock near the water pump. I only hear it at idle and when it knocks it also causes the belt tensioner to jerk. This problem just started after installing a new Holley 670cfm TBI. Any help would be greatly appreciated
     
  2. mudjunkie 82

    mudjunkie 82 1 ton status GMOTM Winner

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    could be the bearing in the tensioner pulley..... /forums/images/graemlins/thinking.gif /forums/images/graemlins/thinking.gif /forums/images/graemlins/dunno.gif
     
  3. bleedchevy

    bleedchevy Registered Member

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    maybe water pump?
     
  4. erin3183

    erin3183 Registered Member

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    Has anyone heard of a water pump making a knocking sound. I thought that they usually just start to get leaky when they're going bad
     
  5. kennyw

    kennyw N9PHW Premium Member

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    You have a bearing going bad on one of your accessories. When the bearing freezes up it stops the pulley causing the belt to pull tight and that will jerk on your belt tensioner. The knocking sound is the belt tensioner as it gets jerked from a stalled bearing. It could be the alternator, water pump, p/s pump or idlers. Just take the belt off and spin each accessory by hand individually to see if you can tell which one it is.
     
  6. erin3183

    erin3183 Registered Member

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    Thanks, I'll give that a try and hopefully narrow it down.
     
  7. crawlink5

    crawlink5 1/2 ton status

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    This ain't likely the problem, but keep it in mind.

    I changed a tensioner on a Dodge van last month that was jumping. At first I thought something was freezing up, but the spring tensioner was weak - it was 4 months old and put on at the dealer for $275 parts and labor.
     
  8. HarryH3

    HarryH3 1 ton status Author

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    [ QUOTE ]
    the spring tensioner was weak - it was 4 months old and put on at the dealer for $275 parts and labor.


    [/ QUOTE ]
    OUCH!!! I knew there was a very good reason to still fix my own rigs! /forums/images/graemlins/thumb.gif
     
  9. tomseviltwin

    tomseviltwin 1/2 ton status

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    Maybe, your flexplate is cracked and the bolts are tapping against the inspection cover. It is very hard to determin where sound is actually coming from and will make your belts bounce.
     
  10. chevyracing

    chevyracing 1/2 ton status

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    This may be out of the ball park but did this engine evr have a mechanical fuel pump on it, for instance before the TBI was put on? If so did you take the fuel pump push rod out?

    John
     
  11. erin3183

    erin3183 Registered Member

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    I figured out what the problem was once the alternator stopped charging. The rear bearing was no longer present(completely gone) when I removed the alternator to install the new one. Funny how I'm listening with my face right next to the alternator but the sounds doesn't seem to come from it, though with the new one installed, all is good. Thanks for all the input and good luck.
     
  12. steelsoldiers

    steelsoldiers 1/2 ton status

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    Cool, glad you got that sorted out. If you think it's hard tracing down a knocking part on a gasser, you should try it on a 6.2L diesel /forums/images/graemlins/1zhelp.gif /forums/images/graemlins/grin.gif
     
  13. erin3183

    erin3183 Registered Member

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    Yeah, I bet...
     

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