Hey everyone. My 1991 4.9 makes a weird noise. Sounds like it's coming from the area of the alternator, and changes in speed when the pedal is pressed. Other than the noise it drives and idles great. What could it be? Video to noise is here:

 

Sounds like a pulley bearing getting ready to explode and take out the radiator. Take the belt off and spin each thing by hand

 

Are all of the pulleys supposed to spin freely or what?

 

If you remove the belt everything but the one on the crankshaft will spin by hand fairly easily, it'll take some oomph or a wrench but you can also move that one too.

 

I got my belt off, all the pulleys are in great shape except the alternator pulley. The alternator pulley has quite a bit of play in it. Should I tighten it or just get a new alternator? I understand the bushings could be going out which caused it to loosen in the first place.

 

New alternator. Or have yours rebuilt