captainty

I just took a 03 f150 lariat fx4 with a 5.4 with 114000 km home from the dealer for a test drive overnight and there is a wierd whining noise over 50km/h and you can only hear it when you press the gas. once you let off the gas the noise disappears. The rpm is usually around 1000-1200. also when you sit in park you can hear it outside of the truck. it also idles a little rough around 500-600, just around that mark.

it has been sitting for 2 months or so, but is this a normal noise to have? Ive had a 05 f150 with a 4.6 and never had this noise.

any ideas?

thanks in advance!!

Good old Bill

First thought coming to mind was blown out of the water with the second sentence. Are you sure the noise is the same? Thinking rear end whine while at speeds, typical for it to come and go with throttle. Sitting still, wondering about air cleaner installation. Is it on right and tight? Does the engine seem rough at idle, thinking vacuum leak? Have read other posts about the alternator bearings making noise, jury is out on that one.

captainty

yeah im positive that its an idependant noise with the throttle input. I got up to 100 km/h and the noise seems to fade away. but its really loud at 50-60 km/h. The air cleaner is on tight.

but yeah its a wierd noise, expecially since its only noticable when i press the gas. stange eh?