Strange Noise coming from engine compartment

[Gary&Terry]

I just developed a "mystery noise." Sounds like a spinning noise, Happens when the engine is pulling, and is more prevalent when engine is cold and it sounds like its coming from the left side of the engine compartment. It doesn't seem to affect performance at all. I thought maybe it could be the power steering pump. Any Ideas?

Gary

[ccjohnson]

Maybe an alternator bearing?

[DavidBall]

Do you have a turbo boost gauge, maybe the hose connecting to it has a slight leak under pressure and you are hearing the noise from it. Or air intake ducting there is a lot of suction inside the air duct to the turbo.

Just an idea,

David

[The Newell]

Check all the air to air connections as well as all hoses. I have been told a noise like a baby crying can come from a loose boost hose

[ccjohnson]

On other thought; possibly a belt tensioner or idler pulley. Please let us know what is ends up being!