85 N/A, its not a belt, im not a ninny.

its mostly at 2500 rpm, and occasionally in the lower 1000s. i can't make it do the noise while playing with the throttle from under the hood. i konw its nothing from the belt drive. belts replaced a month ago, all tight and good. it sounds very mechanical...just like nails on a chalk board, its only for a small cherp, maybe half a second.

thanks for any help

 

Although I love the "lets guess the noise" game, it would be much easier to help you if you can post a video with the noise (loud and clear).

 

z31 belts need to be a lot tighter than you would expect (in relation to other autos you may have worke on) to eliminate the squeal. belt dressing helps but tight belts are a must.