Oldsmobile/Buick Repair: water pump pulley, buick park ave, lifetime warranty

Question
Hi, I have a 95 buick park ave. with 145,000 miles. I had the water pump replaced about 2 years ago with maybe 20,000 miles since replacement. Last night out of nowhere the car started to make a loud scrapping noise with a burning metal/rubber smell. We made it home and I checked under the hood this morning. Seems the water pump pulley is warped and is grinding into the motor mount. Does this mean the water pump is bad or can the pulley just be replaced.There is no leakage from the pump. I would like to know my options before I take it back to the shop for repair because they are expensive and I wonder if I could replace the pulley myself. Thank you for any feedback.  

Answer
Hi Jim,
The first thing I would do is remove the tension from the belt, and wiggle the shaft of the water pump.
I would consider it quite unusual for the pulley to just bend while in use. I'm thinking the bearings must be bad.
As for the pulley, I believe you could just unbolt it and replace it. Call a parts store, and ask if a new pump comes with a new pulley or not, and if it requires being pressed on during assembly.

Another thought, is where was the replacement pump purchased, and did it come with a lifetime warranty.

Van