Water Pump Knocking ??? 1991 305 Caprice

[danglovan]

My 1991 Caprice w/305 is making a knocking sound that sounds like it is coming from the water pump. I used a screwdriver at various places and the top of the water pump was the only place the sound came through. It isn't over heating (yet?) but I don't want to wait until it does.

Do you have any tips for confirming the water pump should be replaced or if I need to take it to Chevy for diagnosis?

I would also appreciate any remove/replace info since the last water pump I replaced was in my 1953 Chevy Belair.

Thanks for any help.

Dan

[at1212b]

I just replaced my water pump on my 89 Caprice and got a lot of great advice info from the members here... http://www.automotiveforums.com/vbul...d.php?t=711892

I too heard the ticking noise since I got my car (though I didn't know it was coming from my water pump). It started leaking and overheating recently and ever since I changed it, that ticking noise is gone and my runs alot better so my advice would be to change it before it fails (especially if you don't know when the last time it was replaced). I'm very glad it was changed.

Its not too hard as long as you have the tools (very basic tools) and definitely get a repair manual book to just reference. It also helps alot to have somebody just help out to hold the waterpump while you're screwing the bolts in and etc.

Don't forget to change the thermostat too which I forgot to and replace the hoses if you can.

[silicon212]

Originally Posted by danglovan

My 1991 Caprice w/305 is making a knocking sound that sounds like it is coming from the water pump. I used a screwdriver at various places and the top of the water pump was the only place the sound came through. It isn't over heating (yet?) but I don't want to wait until it does.

Do you have any tips for confirming the water pump should be replaced or if I need to take it to Chevy for diagnosis?

I would also appreciate any remove/replace info since the last water pump I replaced was in my 1953 Chevy Belair.

Thanks for any help.

Dan

It could be either the water pump (you should see rust trails near the weep holes, even if there's nothing wet) or a slack timing chain (right behind the water pump). I'd do the water pump anyways, as they're cheap and you'd have to take it off if the timing chain was slack anyway. Put it together, and if it still knocks, then it's likely to be the timing chain.