I have a 2007 F-150 with the 5.4 engine. When I'm driving I hear a weird whining noise coming from the engine compartment. It gets louder with RPM's not speed. Any ideas on what this is or how to find out and fix it? I have go home and drive about 300 miles in 3 weeks so I need to figure this out before I leave.

Thanks in advance.

 

Do you live in a cold climate? If so it's most likely the alternator problem. People including myself who live in cold climates experience this whine from the alternator when cold. After the truck warms up the noise goes away. Ford did a TSB a few years back which addressed this problem. You will be fine though if you don't fix it. Mine has done it since I have gotten the truck and I have yet to fix it and haven't had a problem because of it.

Search this forum and you will find all the information your looking for.

Good luck!

 

You prob have a bad belt idler. The grooved idler next to the PS pump is the one that I see fail the most. Put a prybar on the pulley bolt with the engine running and put your ear to the handle. You can check the other pullies and the alternator with the prybar too, but I bet it's the grooved idler.

 

my 07 does the same and it slowly got louder over time but has been like this for awhile with no issues but i also think its a pulley but its funny because it sounds like a supercharger when you get on it.