97 ram 2500 4x4, 5.9 V8, 46re.
Alternator is newish, output and diodes tested good, all my pulleys are okay as well. Don't seem to have any vacuum leaks of any kind either. Almost sounds like the right front in the engine bay, however I don't have much of a way to check since its intermittent and only does it while moving. It went the whole summer without making the noise, however since it has cooled down it has started again. Today it started happening every couple of minutes. It doesn't appear to be speed or RPM related since the noise doesn't go away if i slip it into neutral and shut it off. Seems to fade in and abruptly stop.


Link:

 

Can't really hear anything over the exhaust. Have you checked the brakes? Squealer starting to hit the rotor?

 

The brakes are relatively recent, all looking good down there in the wheel area. The sound is definitely coming from the engine area and is very loud outside the truck as well

 

Does the noise stop when you step on the brake pedal?

 

Nope. Also doesn't seem to matter if I'm driving like a grandma or stomping on it. I'm just hoping its not electrical, but it sounds to me like that is likely.

 

I'm also thinking it's not a wheel bearing, as the noise is the same whether i'm going 45 or 75.

 

What about the wheel u joints, They fail and make noise. Also may want to inspect the cad.

 

Wow, that's annoying. Like some little girl screaming really high. How about the water pump? Fan clutch?

 

Warter pump is still in good condition, and i have an efan. Last time I was in the cad everything seems okay, but I will pop it open and check again tomorrow. Sometimes I do feel as if I hear a slight whine from the diff, however my falkens are fairly noisy. Ill pop the diff cover off as soon as I'm able to get more fluid and see how it looks in the carrier as well.

 

E fan motors?