Screetching noise!!
May 31st, 2008, 3:45 PM
#1
CF Beginner
Thread Starter
Join Date: May 2008
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
Screetching noise!!
I have a 2001 4.8 Silverado, i get this screetching noise from under the hood, only when my fan switch on the dash is on, doesn't do it when it's turned off, and it doesn't matter whether the AC is on or not, this noise comes and goes, and happens more often when i'm on the peddle and kicking it down to a lower gear, noise will last up to 4 or 5 seconds, sometimes shorter. I replaced my alternator last year for a 130 amp instead of the original 105 amp, with that, i also replaced the serpentine belt, both were aftermarket, thinking that my noise problem may have been from an aftermarket belt, i replaced it today with a genuine GM belt, problem still there, anyone have any ideas?
June 2nd, 2008, 12:47 AM
#3
CF Beginner
Join Date: Jun 2008
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
RE: Screetching noise!!
interesting....
so you hooked up a higher output alternator without beefing up the rest of your electrical system to handle the increased current? that's a recipe for disaster. all of the wiring in your truck was designed for the alternator from the factory. you're pushing alot more power through it and that's probably the source of your problem. have you verified where the squeal is coming from? put the transmission into neutral, block the wheels, and rev the engine and look under the hood to try and pinpoint the source of this squeal. i doubt it's the belt, but there's a surefire way to find that out. if your belt has been slipping, it will be shiney and slick on the part that contacts the pulleys. if that isnt there, you aren't slipping the belt. slipping belts create alot of friction, and it visually presents itself this way. how hard is your fan blowing? does it seem to increase speed/intensity when you hit the gas?
so you hooked up a higher output alternator without beefing up the rest of your electrical system to handle the increased current? that's a recipe for disaster. all of the wiring in your truck was designed for the alternator from the factory. you're pushing alot more power through it and that's probably the source of your problem. have you verified where the squeal is coming from? put the transmission into neutral, block the wheels, and rev the engine and look under the hood to try and pinpoint the source of this squeal. i doubt it's the belt, but there's a surefire way to find that out. if your belt has been slipping, it will be shiney and slick on the part that contacts the pulleys. if that isnt there, you aren't slipping the belt. slipping belts create alot of friction, and it visually presents itself this way. how hard is your fan blowing? does it seem to increase speed/intensity when you hit the gas?
