I have 140,000 miles on my 2005 F-150 and for the past year I have noticed a somewhat high-pitch whistle or howling sound coming from either the front or underneath. The pitch and volume continuously varies as though it is just tire howl, but I just changed all four tires and no results. It gets much louder at about 65 mph and 78 mph, but I don’t hardly hear it at any other speed. My brother says it’s just a wind whistle, but I strongly disagree as it doesn’t change when i drive against or with a strong wind. I rely on this pickup for work and can’t afford to be without it for more than a day or two, so, for peace of mind at least, I would like to know what is making the sound. Has anyone seen this problem or have advice?
Does it change at all, comparing when you are in gear at a speed that produces the sound vs the engine idling and coasting at the same speed?
You might find quiet road and drive at the speed producing the greatest noise and steer from right to left, listening for any change in the sound. If it is wind noise applying masking tape to gaps in body panels such as the hood to fender and door to cab will eliminate the noise and allow narrowing down the problem area. Loading a few hundred pounds of weight against the tailgate will change the rake and if the noise is from the wind passing under the front of the truck a change should be noticed. Noises at high speed are very difficult to isolate. Good luck.
I believe your brother is right. I had a whistle that sounded a lot like yours and it turned out to be a piece of plastic windshield trim that had split on the corner. Hard to find but real easy to fix.
The noise might be coming from the radiator fan clutch.
http://www.rockauto.com/catalog/moreinfo.php?pk=1793680&cc=1430669
With the engine cold see if you can wiggle the radiator fan. If you can it’s the fan clutch.
Tester
Thanks everyone! Looks like I have some troubleshooting to do. I’ll let you know what I come up with.
Something to keep in mind
“tire noises” which don’t go away are often in fact a failing wheel bearing
I have the same year F-150 and the exact same issue. New tires, rotors, calipers, break pads, alignment, completely replaced the entire front end, new pinion seal and still have the same high-pitch whistle/howl. Did you ever figure out what the issue was? I know this is a long shot since it was a long time ago.