Diagnosing an Squeaking Alternator/Idler Pulley
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Diagnosing an Squeaking Alternator/Idler Pulley
Hi all,
I had my indy replace my water pump some miles ago and he noticed this (see video) when he spun the alternator. He quoted me at $1200 to replace the alternator and all the pulleys, but I declined because I can DIY that stuff! Anyways, fast forward to last month and I've started hearing a whining noise at 3.5k+ RPMs that increases with throttle and revs and completely dies below 2.5k RPMs. You can hear a slight squeak in the video when he spins the alternator. My question is: from the video can I assume that this is the pulley or could it also be the internal bearing? If it's the alternator, I'll replace it this weekend with a rebuilt one. Interestingly, I've tested the alternator's recharge and it is excellent at 13.8 volts.
I had my indy replace my water pump some miles ago and he noticed this (see video) when he spun the alternator. He quoted me at $1200 to replace the alternator and all the pulleys, but I declined because I can DIY that stuff! Anyways, fast forward to last month and I've started hearing a whining noise at 3.5k+ RPMs that increases with throttle and revs and completely dies below 2.5k RPMs. You can hear a slight squeak in the video when he spins the alternator. My question is: from the video can I assume that this is the pulley or could it also be the internal bearing? If it's the alternator, I'll replace it this weekend with a rebuilt one. Interestingly, I've tested the alternator's recharge and it is excellent at 13.8 volts.
Thread Starter
Rennlist Member
Joined: Jun 2024
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I think I'm just going to replace this alternator altogether. I found a Bosch unit for around $350, but got it down to $250 with a handful of Amazon gift cards I had laying around. Hopefully install goes smoothly!
Instructor
Joined: Aug 2022
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From: Australia
Having said that , if it were me I would not throw that alternator out , and just for fun refurbish as a better "exchange part" for the future. Unfortunately , my experience with a lot of newly made replacement car parts is nothing above "WTF ??" I read an article that a lot of car manufacturers are ditching their old tooling to "upgrade" for EV vehicles. Total insanity if you ask me !
Hey, don't shoot me I'm just the Sherrif,
..err deputy
Last edited by Der Mechaniker; Today at 05:30 AM.
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From: Northern CA (209)
"While you're in there" replacing the alternator, it's difficult to see if the condition of your oil filler tube- if it is the original or had been replaced in the past but these tend to crack or break over time due to it being plastic and heating up/cooling down. This may save you labor time and/or money down the road if your oil filler tube needs to be replaced because in order to get to it, the alternator has to be removed.
RL Community Team
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From: Atlanta
Read some of my debacle here: https://rennlist.com/forums/997-foru...egulators.html
Peace
Bruce in Philly (now Atlanta)
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Doing this at my buddy's place a short-drive from mine. He's well equipped and has one of those battery/alternator testers. Will run a full test on that Bosch unit I bought off Amazon (
) and let you all know how it performs! With any luck that squealing will be gone. Still have to address the squealing in my front left suspension! Started after my recent refresh and every part has been replaced; down to the subframe as most know! May do a thread soon on that if I can't figure it out myself this weekend.
