Have you checked your belts too see if they are tight?
Sometimes you can give a squirt of brake cleaner on the belts while it is
running (dont spray near exhaust manifolds it is very flammable) to see if
the sound goes away, if so you may have a loose or worn belt.
Sometimes you can give a squirt of brake cleaner on the belts while it is
running (dont spray near exhaust manifolds it is very flammable) to see if
the sound goes away, if so you may have a loose or worn belt.