Still Noisy

My 98 is still making a high pitch noise. Any help is greately appreciated as this is sooo annoying. Here is my diagnosis so far. It generally happpens on cold starts. It's VERY high pitched and does not sound like a typical belt noise. When I listen hard with the hood up, it seems to maybe be under the grey top cover over the engine. Often, after the car warms up, the noise goes away. Especially after the car restarts when warmed up. The noise happens between idle and 1400 RPM, where in that range the noise gets higher pitched progressively until it dissappears at about 1400 rpm. Today, when I put my hand on that grey engine cover, it seemed to muffle the noise a bit too.

Any help is appreciated. Thanks!!!

Could it be a tiny vacuum leak that's squeaking?

Eh. My 95 does the same thing. It goes away so I haven't froze my nuts off trying to figure out what it is. Doesn't seem to happen unless it's down around 10 degrees or lower.

Once again we should all kowtow to indy- my first thought was it sounds like a vacuum leak.

My first thought was a vacuum leak also. My logic in it going away is that wherever the leak is warms up and seats better. I guess yesterday I got a little worried when it sounded like it was under the gray cover. I had a horid mental thought that the noise was like when turning metal on a lathe without the coolant/oil.

Start it up when cold, pop the hood and rev it by hand and listen for changes. I would remove the engine cover until you locate the source.