99 Tahoe

[azmotorsports]

I have a 99 Tahoe and replaced the water pump 2 years ago now it's making a whinning sound. I realized that it was leaking a little fluid fromt he thermostat, so I replaced it but it's still making the sound here and there. It's NOT running hot and not leaking any fluids but does that sound indicate that the pump needs to be replaced?
Please help.

thanks.
c

[kenny-1907]

Are you sure it is the water pump making this noise ? A neat trick to try is get a piece of metal bar approx 2-3 feet long , place one end of the bar on your water pump while the vehicle is running (becareful of the fan/belts ect) and put the other end against your ear and cup your hand over the rod to your ear. This will allow you to hear if it is a bearing going in the pump or not. I have a feeling it may be your alternator , i had mine whine on me one time, the voltage regulator went and it was charging at something stupid like 17 or 18 volts. Good thing it was the middle of winter and the battery kept cool eventhough the alternator was not (burnt off my thumb print when i touched it) This trick with the metal bar works well for other rotating parts with bearings as well.

[azmotorsports]

Good tip, thanks Kenny. As a matter of fact I replaced the battery last month too and never checked the alternator. I'll check it out tonight.

[skipr]

Originally Posted by kenny-1907

Are you sure it is the water pump making this noise ? A neat trick to try is get a piece of metal bar approx 2-3 feet long , place one end of the bar on your water pump while the vehicle is running (becareful of the fan/belts ect) and put the other end against your ear and cup your hand over the rod to your ear. This will allow you to hear if it is a bearing going in the pump or not. I have a feeling it may be your alternator , i had mine whine on me one time, the voltage regulator went and it was charging at something stupid like 17 or 18 volts. Good thing it was the middle of winter and the battery kept cool eventhough the alternator was not (burnt off my thumb print when i touched it) This trick with the metal bar works well for other rotating parts with bearings as well.

This also works with hollow small diameter pipe, like 1/2" emt conduit.

[azmotorsports]

The noise is gone but I'm dripping fluid from some where that I can't locate and the truck in NOT running hot. Should I just replace the water pump and where else besides the thermostat water pump could it be leaking?

[decoy86]

Check the Quick Disconnect water line behind the Alternator. This is a horrible design from GM and it leaks all the time. Be carefule if you have to replace it as it will break off into the intake (just happened to me last week).