Hi panther people,

I've been looking around for an answer to this question, and while there are a few similar threads on here, nothing I've read sheds any light on this issue. I recently bought a 2008 CVPI, which had 123,702 miles on it at the time of purchase. She's now got 124,050. Overall the car appears to be in very good shape, new(ish) intake manifold and valve covers, etc. Aside from some intermittent odometer issues, the one thing I can't figure out is this noise that happens with harder acceleration.

The noise sounds like a grinding type sound, but I can't figure out where it's coming from. My first thought was the belt, which had some unusual wear on the top, almost like someone installed it backwards before putting it on the right way. I replaced the belt yesterday, and before putting the new one on, I handspun everything to make sure the noise wasn't coming from there.

I noticed that there's no noise with smooth steady pressure on the accelerator. However, stepping on the accelerator with a little gusto (i.e. getting up to speed to merge onto a highway) triggers the noise. The noise stops as soon as I let off the gas. I noticed it merging onto a highway and even on the street when stepping on the gas. Not sure if it only happens in certain gears or rev range, but noticed it yesterday between first and second gear around 1,500 rpm. The noise does not happen when the car is revved while in park or neutral, which leads me to suspect this might be a transmission issue?

Going to try to get some audio/video of the sound. Until then does anyone have any thoughts on what this might be?

Much obliged.