It could be a partially blocked catalytic converter or damaged exhaust system.
I have a 98 Mustang that has had the original air flow system removed and replaced with a mass air flow system with a K&M air filter and it whistles also which I was told is normal???, so if your air flow system has been changed to a mass air flow you may want to change back to the original air system with the enclosed filter. Most people do put a mass air flow system on and then realize they hate the sound and switch back. Just my experience.
mustang cobra it has an 8 cylinder engine which makes it so loud
unless it is running fine it could be a vaccum hose leak. some vehicles have plastic intake which causes them to suck air louder, and can give off a whistling sound.
You probably have a vacuum leak. Check and replace all of the rubber emissions hoses around the engine.
It isn't louder (loudness has to do with intensity, and a small whistle can't generate that much intensity), it's a higher frequency. In the range that is inaudible to humans.
It gets louder and then gets quieter
I guess it just makes it louder than regular whistling, and gets peoples attention.
jet engine
i have the same problem, my Audi a3 tdi 110 seems to be running louder than most diesels engines.
No, a jet engine is louder.
Diesel trains are louder than electric trains because you the noise that the diesel engine makes, which is louder than the electric engine.
best of both worlds by hanah Montana
A worn serpentine belt will make a high-pitched squeal when the engine is running. The faster you go, the louder the high-pitched will become.