sounds like a cylinder misfire..check spark plugs and wires..usually a code will show which cylinder it is, should replace all though
a loose or slipping belt
Faulty engine
I think that the sound will be aborbed by the object then come out the outher side as if you put ear phones on.It keeps the sound in as much as it can.If it is totally covered it will be MUFFLED. new ans: the object will absorb all the energy and the sound will come out muffled.
Detonation...Needs to be fixed immediately or will eventually destroy engine.
Also engine turn but has a muffled sound when trying to crank. I was diving car home and car just died and would not start back up.
Snow does not reflect sound well, it absorbs it. So everything you would normally hear after is muffled.
An engine might sound like a diesel at operating temperature if the engine was a diesel or if there was an issue with the manifold. Sometimes gases escaping the manifold cover could cause the engine to sound different.
incomplete combustion of fuel
throttle body
Interesting question. If the car's engine cause the car to reach the speed of sound, causing a shock wave, then the engine did indirectly cause a shock wave. The engine itself creating a shock wave however, is highly unlikely if not impossible. The moving parts in a typical combustion engine do not get anywhere near the speed of sound and any car that would reach the speed of sound would most likely have a jet engine like Thrust SSC.
Water does not work well with sound waves. All sound will be muffled so i would not bother buying such a product. They probably do exist though. And if they do, the only place i would use them is in the shower.
slipping alternator/power steering/ auxillary drive belt