I have a 1998 Chevy K1500 with the 5.7 and I’ve had this belt squeak for months and can’t get it to go away. I have replaced the alternator(twice), belt (4 times), tensioner and idler(twice), water pump and pulley, and crank pulley. It is driving me insane and I don’t know what else to do on it. Please help!
Greetings & Welcome to the GMT400 forum!
Serpentine belt drives last so much longer, don't need periodic tightening,
& overall are so much better than the old V-belts they replaced.
But in exchange for all this they are
pretty very fussy about all the pulleys
being in the same plane. (That is, no pulleys protruding or sunken, front-to-back
perspective as compared to all the others working alongside.
When we're troubleshooting in this forum, sometimes a sharp photo really is worth
a thousand words. How about this? If you can get a helper to take a sharp photo
while you hold a long straight edge (think sheetrock square, see attached) across the
faces of the pulleys in a couple of different orientations (left to right, up to down,
across the crank pulley on the bottom to individual pulleys, etc) there's a
really good chance that if there's a problem either you will see it, or someone
in here will scope it out while pouring over the photo.
NOTE: Can you further define the squeak a little? Constant, steady squeal,
or is it a chirp chirp chirp. Is it right from a cold start, or only after it
warms up, or instead gets quieter when warm? Is it somehow related to the A/C
compressor w/clutch applied, and lessens/disapppears when off?
(A/C *or* Defroster modes)
One last thing? What does it take to get the squeal to disappear? Or
if it won't ever disappear with the belt installed, have you ever tried running the
engine for a few seconds with the belt completely removed? Chances are
the squeak will disappear with the belt off...but on the off chance that the
'squeak' is still present then we need to inspect the spinning stuff for some
sort of interference. (harmonic balancer in front, flywheel/flexplate rubbing
on the inspection cover, weird rub under the timing cover, strange leak
having to to with the brake vacuum booster, etc.)
I've chased my fair share of stubborn 'squeals' over the years, and by now
I am no longer surprised by the wild sources of where sounds can originate
inside an engine bay.
See what you can discover and report back with your findings.
PS: In order to get a better idea of where the noise is coming from,
using the center tube from a paper towel roll is both free & effective.
Happy Hunting --