Update on that weird vibration in the old boiler at the Trenton plant...
Turns out the whole thing was just a loose baffle plate that had shifted maybe an inch over the winter. The sound went from a full-on death rattle to a quiet hum after we tightened four bolts. Anyone ever have a fix that simple for a noise that scary?
Has a buddy ever told you about a noise that turned out to be something totally dumb? My friend's car started doing that same death rattle, and he swore the engine was toast. Spent three days tearing it apart, checking belts, pulleys, everything. Turned out a loose heat shield was just banging against the exhaust at certain RPMs. He felt like a real idiot, but at least it was a cheap fix.