Ford Explorer "Whining"..?

[Dellfin]

I own a 2005 Ford Explorer V8 with about 60K miles. Over the course of the past few snowstorms I've manually engaged the 4x4 high a number of times. I engaged the 4x4 low once and properly disengaged. It "seems" to me that I am now hearing what is best described as a whining that sounds like a electric motor coming from the front end upon acceleration. The faster I go the higher pitched the whine. I think it's coming from the front axle, but I truly have no idea. (Alternator bearing perhaps?) I have never heard this from the truck before this winter?

Are there any mechanics or others handy with Fords who may have an idea for me?

Thanks!

[Scott K]

Does it make the noise by just revving the engine up? Or do you have to be driving down the road? Does the truck seem to be binding on turns?

[Dellfin]

Great question; I'll need to drive it again to hear if it happens while revving, but I think it only occurs when in forward gear and driving. Definitely not binding while in motion or turning.

[fishing tech]

Wheel bearing if it happens while driving.

[crappiegetter]

I will agree on it being a wheel bearing if it is only happening while driving.

[Dellfin]

Thanks for the replies so far. I've concluded that the whining occurs when the engine is revved and not only while in motion. This brings me back to my original suspicion that it's a bearing in another component...alternator??? My charging system check on the system check says "OK".

Would a shop/mechanic be able to find out isolate the cause using a stethoscope thingy or do I just need to wait for something to fail? I'd hate for something to go wrong on a trip to Mille Lacs or LOW and be stranded, but I just don't know how to be proactive on this one...!?!?

[jeffreyd]

bad belt tensioner or a alternator going bad. i would remove the belt and spin each pulley by hand to see which one is going south. i have one that is starting to make noise so that will be my new years project to replace them. good luck

[Tom7227]

My F150 whistles when it's cold out. i think it's some sort of intermittent vacuum issue. I was trying to play Jingle Bells with it last week and darn near got a ticket.

[Scott K]

My F150 whistles when it's cold out. i think it's some sort of intermittent vacuum issue. I was trying to play Jingle Bells with it last week and darn near got a ticket.

The f150's had issues with that when it is cold, usually just an iced up pcv, or iac. Nothing that will effect your driving, other then your sanity!

[fishing tech]

If not a wheel bearing I would say idler pulley or belt tensioner.

[Dellfin]

Prize goes to jeffreyd and fishingtech. Bad tension pulley bearing.

[Farley]

Does it make the noise by just revving the engine up? Or do you have to be driving down the road? Does the truck seem to be binding on turns?

What would be the issue if it was. I think my truck has this issue as well and it seems to bind when I turn in reverse? Wheel bearing? Also whines when the motor is revved so maybe not a wheel bearing?