Buick Regal acceleration noise-HELP

'98 Regal LS with 107,000 miles (non-supercharged). Its 30 degrees outside. When the car first starts and I press the gas I hear a low chattering/clicking/swishing type noise. It happens both in when the car is in park or when its moving as soon as the gas is pressed. It goes away once the engine is warmed up and doesnt come back until its sat out in the cold for several hours. Its hard to hear it with your ear under the hood but easier to hear in the drivers seat. I took a video of the sound. Its faint but you can hear it...it almost sounds like someone is moving around inside the car. Please help me diagnose this!

http://www.youtube.com/watch?v=th99FmZ6hAs (http://www.youtube.com/watch?v=th99FmZ6hAs)

P.S. The power steering pump is starting to feel worn....I assume the power steering pump is going to fail in the next year or two.

Check the pulleys on the belt tensioner. They may be worn and causing the issue. Once the pulley bearing warms up it goes silent.

It was actually replaced not too long ago....your pretty sure it sounds like a bearing noise then? It was warmer last night and the sound went away. It's below 30 degrees tonight and it came back

Not absolutely certain but this is a good place to start. Have you tied listening with the hood up to try to get a better isolate the noise location? Is this a supercharged engine?

Not supercharged and I tried listening under the hood but it was too warm and I couldn't hear it. I will try it again tonight

See if the noise is there, on a cold engine, cold day, with the serp belt off....

There hasn't been a cold day since. I took the belt off tonight and the pulleys seemed good other than the alternator pulley. That one seems to be a bit loose. My understanding is that is shouldn't spin more than once or so. Heres a video....what do you guys think?

http://www.youtube.com/watch?v=19K-E2xUeY0&feature=plcp&context=C3005ff3UDOEgsToPDskKllKjcw0RyVGP7iROsW5Qt

Also, an I swap the pulley or do I have to swap the entire alternator? I haven't found any pulleys for sale. If I have to swap the entire alternator my choices are:

$76 Pure Energy Alternator -NEW or $105 NSA Alternator - NEW
What are your thoughts?

Who told you the alternator pulley should only spin once? The more it spins the better....if it's charging ok, leave it alone....that's not your problem, when a bearing goes, the noise doesn't go away...

Let's wait for a cold day, belt off, and see if the noise is there.....

I was told it shouldn't spin so freely like it was. I will have to wait again for a cold day and try with the belt off.

Took the belt off tonight and the noise went away. I spun the alternator and its a little bit louder tonight. I'm starting to feel very strongly that it has to be the alternator bearing because its getting noisier. The noise must get worse the faster it spins. When I put the belt back on the noise came back immediately. Every other pulley is tight and spins smoothly? I was thinking I should give it a try?

Agree, if the sound went away with the belt off the alternator try another one and see what happens. If the noise goes then problem solved. If not then look at the other pulleys as a possible cause.