Why do diesel locomotives sound like loud vacuum cleaners when they are running power. Does it have to do with gas combustion?
They're noisy because they're huge machines that have no reason to be built to be quiet.
power makes noise. sure, the noise could be muffled better -- which would reduce power output and require more engines burning more fuel to move the same total load. why don't locomotives use less noisy engines? effectively the only less noisy engine is third rail electric. [gas turbines can't be used -- the gas is explosive in ordinary air and thus huge hazard in derailment or other accident.] third rail electric is very expensive of installation cost -- so much so that it is impractical [too expensive] for all but the most frequently used trackage.
