Here's the issue with my truck...

When I start it after it hasn't been run for a while (after it's cooled off) it whines a little during start up...typical. However, if I immediately start driving the is a very distinct whining noise coming from somewhere in the engine compartment or maybe at the front of the passenger compartment. It whines until it warms up. It occurs between 1500 and 3000 RPM. Outside of that range it doesn't whine. I also noticed this issue in higher elevations or if temperatures go below 50 degrees outside (trip to Big Bear). It will whine even if it has warmed up under those circumstances. Any help??

2006 Ford F-150 5.4L FX4 SuperCrew 6" Fabtech Lift 35" Tires Dual Flowmaster Exhaust

cam synchronizer?

Get your battery load tested. It may be getting weak and alternators WILL whine when they have a heavy load.

It might be the power steering pump. Use a turkey baster to suck all the PS fluid out of the reservoir that you can and refill with synthetic Mercon V ATF. Drive it a few days and repeat till you have used up a quart bottle.

Here is the link for the video of my truck...if you know what that whole not starting thing at the beginning is about that's a bonus haha. The whine is best heard at 2:36 and 2:45

deff something on the belt drive,most likley the alt, from having to charge the dead battery.

Idk if you have solved the problem yet but I had the exact same problem and noise with my fx4 and at first i thought it was my power steering pump because of the noise being similar to a p/s pump when its aerating fluid but i did some digging around and diagnosing and turns out it was my idler pulley. here's an old tsb for it http://www.stangnet.com/images/stori...s/08-04-02.pdf there's a new one to include 04-06's but i cant find it on the web. hope this helps out