Alternator or A/C?
Thread Starter
Team Owner
Joined: Aug 2008
Posts: 33,046
Likes: 6,555
From: Rochester NY
St. Jude Donor '09 thru '26
Alternator or A/C?
'92, stock LT-1. I'm getting a nasty intermittent howl, squeal, screech. Although I figure A/C or alternator bearing, I hit the belt with some belt dressing to be sure - no change. I THINK it sounds like it's coming from the alt but not 100% sure, I tried putting a small hose in one ear but still can't pinpoint it. For what it's worth it's about 50 degrees out so there should not be a load on the AC system. Any suggestions on how to verify it's the alternator for sure? Thanks!
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
'92, stock LT-1. I'm getting a nasty intermittent howl, squeal, screech. Although I figure A/C or alternator bearing, I hit the belt with some belt dressing to be sure - no change. I THINK it sounds like it's coming from the alt but not 100% sure, I tried putting a small hose in one ear but still can't pinpoint it. For what it's worth it's about 50 degrees out so there should not be a load on the AC system. Any suggestions on how to verify it's the alternator for sure? Thanks!
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
Never throw parts at a car based what a forum member says
For all you know I could be a keyboard wrench only
Take the serp off and spin the tensioner by hand, then the alt...and so on. You will feel or hear something that will tell you what to replace.
Happy hunting
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Noise is often only present with the load so spinning it takes a pretty sensitive touch. I like using a long bladed screwdriver and positioning it as close to the Pulley as possible with my ear on the other end (ok so I'm sticking it in my ear!). Otherwise a stethoscope the nurse down the street gave me works well too. Just watch your hands (and hair!).
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Team Owner
Joined: Aug 2008
Posts: 33,046
Likes: 6,555
From: Rochester NY
St. Jude Donor '09 thru '26
All good advice - thanks! Ran out of time doing other projects before I had much quality time with the Vette. Wonder if I can tell work I won't be there tomorrow, gotta track down a noise under the hood?
