263k on the clock, did a timing belt by the book and sense then it's made this horrid screech/squeal/whatever you wanna call it. I don't think its a belt noise because it comes an goes when its at a constant RPM for a while, and goes away when the engine is revved. It's very inconsistent, I can go days without hearing it, and then sometimes it screeches when i'm going down the road at a steady speed. It seems to happen more often when its colder out.

Timing belt was replaced along with the idler and a new water pump. All the accessory belts are tight.

Here's a video, you get a good idea of how annoying it is lol.

http://www.youtube.com/watch?v=b6qdqM7pSqo

*after about 10-20 seconds or so idling after the video ended, it would come back. It would also come back holding it steady around 1.5-2k

 

A/C compressor bearing?

 

Hmm never thought about that, if it was, would you expect the sound to change when the A/C is turned on/off?

 

Take the belts off one at a time and run the engine after each one you remove. That
way you can rule out the all of the accessories and belts.

If those aren't the problem, then I would be worried the T-belt job that was done.

 

The thing is the noise wasen't there before the timing belt job, so i dont know how it could be one of the accessories. But ill try them anyway.

What could it be involving the timing belt, maybe a bad out of the box idler?

 

Stethescope.

 

I used a poor mans stethoscope (screw driver to the ear) and couldn't really pinpoint anything, although i didnt really go that far down in sense I was getting nervous getting so close to the belts lol.