SO I have great love for the 5.3 L V8. My 2001 Suburban drives great and runs well with over 360,000 miles on it to date. The problem I have is for awhile now and has gotten worse is what i gifure to be a alternator whine. When it first appeared I just went ahead and replaced the alternator but didnt fix the sound at all. I did buy a reman alternator. I am certain the sound is coming from alternator. diagnosing using a long screwdriver to listen. it changes with RPMs. When letting of the accelerator the sound goes down pitch but it truly sounds like a future laser gun shooting. like pew pew pewww. he steady sound. letting it idle a bit before driving will let it quiet down a bit until driving again. it doesnt happen all of the time either. cold or hot, wet or dry. also ive tried unplugging it while running and sound doesnt change. Trying to be as descriptive as possible.