Anybody have any thoughts on this issue?

[twomanymontes]

Not sure if you have a TBI truck or not. but I had a throttle body gasket get partially sucked in and made a whistling nose on acceleration and at idle. Backing off the gas like to brake, it got quiet. Something to check.

 

[sewlow]

If the 'Tech' told you that that noise is the sound of the alternator charging the battery, slap him upside the head & ask for a different person to be working on your truck. He doesn't have a clue!
Generators charge batteries. Alternators do NOT!

 

[MarkZ28]

Check the power steering fluid level? Low fluid level will make the pump whine. A bad trans pump can also make a whine, check trans fluid also.