I wonder if some investigating using an acoustic imager might help: https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii905 https://www.fluke.com/en

I wonder if some investigating using an acoustic imager might help: https://www.fluke.com/en-us/product/industrial-imaging/fluke-ii905 https://www.fluke.com/en-us/product/industrial-imaging/fluke...