Hey I have a 2004 Mazda 6 4cyl and i am going crazy trying to figure out what is wrong with my car. When ever you start the car a High pitched Whisatle/scream comes from the Engince compartment. I dont think it is coming from the belt but its hard to narrow down. when I tap the gas the tone of the whislt changes but it doesnt go away. when I shut my 6 off it winds down but this is very annoying and I am hoping someone in here can help me out before I bring it in.

Thank you

 

It's a guess but what about the idler pulley bearing? I haven't had any problems w/mine to date, knock on wood, but they are a known problem.

 

Sounds like and idler pulley to me. Or could it be a bearing gone bad on the cooling fan? The "slowly winds down" after the motor is shut off leads me to believe it could be a fan... but who knows?

 

Only problem w/that theory is that the cooling fans are electrically powered, not by the engine.

 

That's kind of why I was thinking it could be a fan... power could still be directed to it briefly, even if the motor was shut off, to aid in cooling things down...