I installed a new timing chain and steel backed guide about 1,000 miles ago and everything seemed to work flawlessly. Now I'm getting a high pitched noise eminating from the engine that sounds more like a 1,000 hz test tone than a mechanical noise. It seems everywhere and I can't pinpoint where it is coming from. The noise is only present at idle and dissapears if you add any throttle.

I haven't checked out the pulleys or anything yet.

The guide on the right was against the chain at the top, but was as far over as the holes would allow. Could the chain have worn down to the steel already?

I'll start pulling belts and look down through the valve cover tomorrow, but I thought I'd get some ideas from you guys first.

check the ps adjuster pulley. bearing can go out and make noise like you describe.

sounds like a bearing. Maybe you over tightened a belt in the reaasembly? Maybe it was on it's way out.

I concur.

Same issue happened to me several years ago... Never pinpointed the cause. Rebuilt the engine, same thing.

Finally replaced the PS idler bearing when I had a spare from a parts truck (seemed to be in better shape), and the sound disappeared!