If it is a main bearing, loading it at a low RPM will bring it out pretty clearly.
I think the high tech approaches that were mentioned are probably in use these days on new equipment where the expected sounds are known and don't deviate too much. I know auto engineers can use sensors to nail down noises and the exact timing as to which cylinder and during which part of the cycle it is happening,.
Last edited by truckernix; 10/08/2019 9:36 PM.
