Knocking Sound near water pump???

[erin3183]

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

 

[mudjunkie 82]

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

 

[bleedchevy]

maybe water pump?

 

[erin3183]

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

 

[kennyw]

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.

 

[erin3183]

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

 

[crawlink5]

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.

 

[HarryH3]

[ 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

 

[tomseviltwin]

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.

 

[chevyracing]

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

 

[erin3183]

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.

 

[steelsoldiers]

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

 

[erin3183]

Yeah, I bet...