I have a 2008 F-150 with the 5.4L. It's developed a noise that sounds like a power steering pump going out, but the pitch doesn't change when I turn. It does change when the RPMs increase or decrease. I don't want to just throw parts at it. My last truck was a 1992 F-150, so is there something with newer model power steering pumps that I don't know?

 

Sounds to me like you have a pulley bearing failing, probably an idler or belt tensioner pulley.

If you feel comfortable and have at hand a long solid metal rod like a pry bar or something, you can place one end of it near each pulley on your engine and then stick your ear to the other end to pinpoint which pulley bearing is the culprit, it will be OBVIOUS when you find it.

You can also purchase a mechanics stethoscope from harbor freight for a few bux. http://www.harborfreight.com/mechani...ope-41966.html

Be careful as you will need to do this with the engine running.

 

I heard that from a friend of mine, but kneeling in front of the grill, it sounds like it's coming from the driver side of the engine more so than the passenger side, where those pulleys are. I'll try it, though. Thanks.