racin4ds

iTrader: (1)

The last few days its been really cold here in the NE VA/WV area and I've noticed a strange whining noise from the front end of my 05 FX4. I kinda thought it sounded like a bad alternator or idler pulley but I notice that when I put it in 4WD this morning because of snow that the sound goes away. Any ideas? There are no signs of leaks or anything from the front dif on this truck and it only has 60k miles.

Anyone else ever run into this?

Bonesofsteel

I had a whine & very loud whistle sound (-40 approx right now) Just had my power steering pump replaced & idler pulley.

driver444

I just posted in another thread. I have the exact same noise, and can't pinpoint it. I even opened the hood to see if I could isolate the noise. I really doubt it's 4wd related. It more than likely just stopped making the noise at the same time you put the 4wd in.

Here's the strange thing, maybe coincidence. It seemed like the colder it is outside, the louder and longer the noise was, and until last night, i would've been right. When I got out of work, it was -3. It didn't make the noise.

As I said in the other thread, it only does it for several seconds. When you put a load on the engine (put it in gear), or rev the engine, it stops, but will start again when it returns to idle. I can't tell if its a air or vacuum type noise or a mechanical noise. The pitch does not seem to change with engine RPM. It just stops altogether when RPM changes.

ktmboyz

alternator

driver444

Maybe a dumb question, but if I get the alternator replaced, what's to say the new one, (being the same part) won't do the same thing? I guess we'll find out. Calling my dealer now. Thanks

ktmboyz

ya I hear ya, I have the same noise in my truck. I can put a new one in under warranty but my thought is if I get a new one its gona be a reman vs the one in it is a new. It seems the new always last longer than the remans we install. So i have just been listening to the noise for now

racin4ds

iTrader: (1)

I believe mine is definitely in the front end or 4WD system, as when I engage 4WD it goes away and when I switch back to 2WD it comes back. Mine does change pitch some with speed and goes away at a stop... I'm an ex-QC guy for Delco Remy Alternator division so I know what a bad alt sounds like when its whining or has a bearing failing and I don't believe this is my problem... Thanks for the tips and ideas guys!

Daver

Alternator

f1filthy

mine was making a similar noise while driving in 2wd,but went away when in 4wd.could hear it when you were driving beside a wall or barrier or whatever.the problem turned out to be the drivers side spindle/hub assy. i changed it as a complete knuckle assembly from a newer truck at a auto recycler.prob solved.

Archangel72

My 05 F150 Lariat made a whining noise this morning sounded like very loud tire hum or maybe closer to like a blower whine. I noticed it happening as I rounded a corner then there was a "thud" and it went away.

Now odd thing I just had the motor replaced and well after that my 4x4 did not work
I tried it right after that "thud" and it worked or well at least the light came on I never moved with it on after that.

Another oddity which may just be me hearing stuff is I thought after that noise and thud I started to get the diesel sounding idle again.. Quite literally 300 - 400 miles on this motor if I failed a cam phaser or something in the timing I am gonna be PISSED