I had my power steering pump replaced 2 weeks ago because of a leak. Shortly after, the car developed a squeal/chirping sound and I took it back to the garage that installed the pump. He attributed it to a worn out serpentine belt and replaced it, no charge. A few days after that, the sound returned, only louder. I was informed the bearings on my alternator were bad and I needed a new alternator. I decided to install a new one myself. Well, the noise was still there the instant I started the car. I went to return the alternator and had the guy at the parts store listen to the car and he said either the idle or power steering pulley is bad. Could the mechanic who installed the power steering pump (who broke my air conditioning line and never told me until I discovered a broken A/C) damaged the power steering pulley and therefore, caused this sqealing coming from the pulley? The idle pulley and power steering pulley are right next to one another, so it's hard to tell which one is making the sound.
Sound comes as the rpm rises when gears are changing and is constant when I'm traveling on the interstate at 75mph +. Can someone help?

 

There are lots of people here that will help you, I'm only one of them.
If you can manage to release the tension on the tensioner pulley assy, and remove the belt from the easiest pulley to reach, then just spin each pulley except for the main drive at the lower part of the engine(crankshaft). Most times you will be able to hear a bad bearing or feel some roughness while turning the pulley that is bad or going bad.

 

Thanks for the response. I recently had a new power steering pump installed and thought it may have something to do with the noise. Sure enough, when I removed the belt, the power steering pulley was almost too tight to turn! I took it back to the garage that installed the pump and much to their 'surprise', they responded, "We don't know how that could have happened!" They had to readjust the pulley by ove 1/8 inch. They put the belt back on I haven't heard another sound!