What would cause a vibrating noise?

[JcsMI]

For a 2010 Ram 2500. 182,000 miles. At speed on the freeway usually I hear like a hum/vibration in the engine. If I remove my foot from the gas it stops. A mechanic said he thought my exhaust manifold was leaking but I have not had it checked. The noise is not noticeable on regular roads mostly only on the freeway. Not the while time. It comes and goes. Sounds like pressure being lost but no change in performance.

 

[Curmudgeon]

Look for a round dial on the console, it says "volume".
Try turning that clockwise until you can't hear the noise any more.

You could also turn your head to the right and ask your passenger to shut up.*


*This plan is not without risks.

 

[04fxdwgi]

Some engines and / or drive trains set up a "resonance" at certain RPMs (the old New Process transfer case for w200/300's did it). Can make things like exhaust parts, muffler baffles and heat shields have a resonance / vibration at certain frequencies. Usually it has an increase of intensity for a few moments when you take your foot off the gas quickly when at speed.

Windshield wipers can do that in the wind, also. Mine does that on super windy days at anything above 45/55 mph