Through an experiment carried out at the ISTA Ndolo Mechanics Laboratory, we want to note that noise, generally considered a disruptive signal in signal processing, can provide useful information in the maintenance Rotating machines. We used an asynchronous engine that we operated it in the Holy State (defect-free) and in the state of progressive defects. The generated signals were recorded and analyzed using LabView and Matlab software, which we were able to show the defect-related change in spectral mapping.