Originally Posted by
Infinity
The good the bad and the ugly.
The good news is that after chasing this issue down by working from the cheap parts to the most expensive, I now have new bearings or pulleys in all locations that make for a smooth running engine.
The bad news is that the most expensive part was indeed the culprit.
After 192,000 miles the harmonic balancer separated and was moving a bit causing the noise. It was tight enough that it held together, and from the outside it looked good, on the back side there were some cracks and places where the rubber was not sitting correctly.
I wish I saw your post earlier, I would have told you it was the harmonic balancer from the start. Im at 199k mine started making that noise around 190k or so and like you I literally replaced all pulleys except the balancer and it was still making the noise. I replaced the balancer and noise was gone. On the positive all the other pulleys are good and new.