a loose or slipping belt
Faulty engine
Detonation...Needs to be fixed immediately or will eventually destroy engine.
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.
throttle body
incomplete combustion of fuel
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.
slipping alternator/power steering/ auxillary drive belt
A defective vacuum line can cause a whistling sound when the vehicle is accelerating. A loose belt can also create a high pitched whistle sound.
collapsed lifter?
it might be a bent piton rod if you or water or somthing into the engine
can you elaborate? engine noise? stationary/moving? ticking, tapping or a definite knocking?
whst causes screeching sound when i turn the key in my car?