Well checked my coolant and was a hair low. Just got the vehicle its a 07 Monte with 3.5 in it.

Anyways I split a little coolant filling up the radiator which was half a cup low at the time I couldn't see the coolant but was full right when I started filling. Anyways the belt was making a higher pitched whine. Have had this happen before and belt was sort of old and cracked so I replaced it with a gatorback. Anyways still making the noise.

Not exactly sure what it could be a pulley, water pump? Everything was fine until I spilt a little coolant onto the belt.

 

Try taking off the belt and checking all the pulley's , spin them and listen for noise and check for any movement Can also check while running with a stethoscope or a home made one ( short stick) and put it on or around pulleys and on alt, water pump, ect. and the other end against your ear and you should be able to locate the sound of the squeal. Gatorback belts usually solve most issue's with noise . Good luck

 

That tensioner will sometimes make a noise too.

 

It is odd because it isn't happening all the time, mostly when it just starts even if its already warm and just ran into the store.

 

Check the fluid level in the power steering also?

 

Power steering was good. I may have to get a quick video of it. Its hard to say its higher pitched and quiter than a power steering noise. Doesn't get worse when you move the wheels and it come and goes as it pleases.