2014 f150 3.7L NOT EcoBoost
 

There is a noise coming from under the hood that SOUNDS like a belt but they all look fine. The tensioner pulley and water pump have both been replaced. It happens when I start the truck and quiets when I get to 5th but doesnt happen ALL the time. When the motor gets warmed up, the sound goes away. But again, it's not every time I start the truck. 2 people have said the alternator but when I have taken it to get checked, the readings come back fine. Suggestions?

I betcha it is the alternator making that noise.

What in the alternator could be making the noise if the readings are coming back fine? Also, can rebuilding it fix the problem?

Bearing. If it is like the old alternators that I have taken apart, the rear alt bearing is just a bushing.

Thanks! We will try that!