I'm trying to figure out what the part number/ name for the top pulley on the main belt. At idle it is making noise and is noticeably moving in an out. I assume the bearing shot. It appears to be pressed on. Any idea how difficult it is to change? What the part number is? 2010 XFR. The pulley is highlighted in the picture below.

Thanks for any advice!

 

That’s your water pump, you’ll have to replace the pump.
You’re not loosing coolant?

 

And you do not want it to fail on the run.

 

Thanks Guys. Yeah I scheduled it for a new pump. Not sure why it didn't occur to me that it was the water pump. Duh. Especially with the symptom. Fortunately it has not leaked yet. The tech told me that you often hear them for some miles before they leak. Once upon a time I would actually changed the water pump myself!

 

I wouldn’t make an exception here, this pump is easier to change than any Chevy I used to work on in my younger days. The only tricky part for me was purging the air, but once I learned about that damn bread screw there was nothing to it... seriously, super easy job.