I recently traded my '97 F150 XLT RC in for a 2003 F150 supercab XLT sport. My new truck has a 4.6L V8, 4 speed auto trans, and 3.55 rear (not limited slip). While driving home after taking delivery of my new truck, I noticed a high pitched whine or hum. I first thought it might be coming through the radio. I turned the radio off and noticed I could still hear it. After driving at different speeds, etc. I noticed that the noise would start at 60 mph and continue until about 65 to 68 mph where the pitch would get high enough that I could not hear it.

I returned the truck to the dealer the following day. The service manager rode with me and told me it sounded like the overdrive gears whining. After doing some more experimenting I really don't think it is coming from the transmission or the rear axle.

As I stated earlier the sound starts at exactly 60 mph and gets higher pitched until it is gone between 65 to 68 mph. It only occurs under light loading/acceleration. If I let off on the accelerator pedal slightly it stops. If I push down on the accelerator it gets higher pitched. If I push down hard enough to drop out of overdrive the sound is still there just at a higher pitch. If I am setting still (transmission in Park or Neutral) and revving the engine I cannot hear the noise. It seems to be throttle position dependant but I have to be moving at 60 mph. I have some of the power steering whine that others have mentioned, but it does not sound like that.

My son has better hearing than I do, so he rode with me and he thinks the noise is coming from the engine compartment. He said it sounded like it is coming from behind the dash on the passenger side.

I now have about 800 miles on the truck and love it other than the noise. I drive 50 miles round trip to work each day and unfortunately I like to drive between 60 to 65 mph! This is exactly where the noise is the worst.

I would appreciate any help in solving this problem. I'm sure the dealer will do exploritory stuff but everytime I take it in I get a new scratch or ding in the beautiful black paint!

 

Could be a wind related noise. The acceleration changes the angle of the truck as the engine kicks in, being the reason why you only hear it when romping down.

 

I had a similar proble 2001 Screw - last year dealer replaced needle bearing valves in transmission , also torque converter. The whine sound is gone.