Hi all, I have a 08 explorer 4.6 3v that has developed a noise that sounds exacty like a power steering pump whine, but when I put my scope on the pump, it does not seem to be there, it seems to be under the drivers valve cover (front). It does not tick, knock or rattle at all to indicate any chain, guide or phaser issues. The noise does increase with rpm, but does not change when the wheel is turned (like most pump noise). It is more prevelant when the engine is cold, but is still there when warm. Any thoughts?

 

Turbo?

Actually, it is more likely to be the cam chains. Nothing to worry about unless it gets loud.