Please help identify noise (video)
Thread Starter
Cruising
Joined: Aug 2014
Posts: 13
Likes: 0
From: San Bernardino California
Please help identify noise (video)
It sounds like it's coming from either the alternator or power steering pump. On cold start, the noise isn't there and then suddenly appears after about a minute.
Thanks for having a look (er, listen)!
Thanks for having a look (er, listen)!
Last edited by petr0lb0mb; Oct 11, 2014 at 04:03 PM.
Instructor
Joined: Feb 2006
Posts: 227
Likes: 2
From: Livingston TN
you can use a screwdriver to put tip on alternator or pulley and stick handle next to your ear to pinpoint noise. also you can take belts off to make sure its not main engine noise to narrow it down.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Get 4 feet of 5/16 vacuum line. Put one end in your ear and point the other in the area of the noise. It will allow you to pin point the exact spot where its coming from.
If you jam a screw into one end of the line and put the screw on each component that is rotating, you will be able to Positively figure out what one is making the noise.
Dont forget to chech each belt tentioner.
Bill
Team Owner
Joined: May 2001
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From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
If you haven't already done it, remove the belt and start the engine. If you still have the noise, check the A.I.R. pump. It lives almost directly under that area. Below, and slightly to the rear of the headlight.
Thread Starter
Cruising
Joined: Aug 2014
Posts: 13
Likes: 0
From: San Bernardino California
Thanks for the tips and pointers everyone. I will go back into the garage tomorrow (it's 1am and I just got home, beat) armed with your advice and report my findings. I'm a dinosaur and so I had never heard of an alternator decoupler pulley before. Also, wasn't aware that C5's used A.I.R. pumps--I thought they disappeared in the 80's. Well, I hope it's not the A.I.R. pump as it costs twice as much as the pulley.
Thanks people. I'll back tomorrow.
Thanks people. I'll back tomorrow.
Advanced
Joined: Feb 2008
Posts: 77
Likes: 1
From: Winter Haven Florida
I just replaced my tensioner pulleys and lower idler pulley, the one on the ac belt. Mine was making the same noise, it just squeaked at first start up and went away but then just started doing it all the time. I also suspected the alternator but turned out not to be the prob.
Thread Starter
Cruising
Joined: Aug 2014
Posts: 13
Likes: 0
From: San Bernardino California
I just replaced my tensioner pulleys and lower idler pulley, the one on the ac belt. Mine was making the same noise, it just squeaked at first start up and went away but then just started doing it all the time. I also suspected the alternator but turned out not to be the prob.
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Tech Contributor
Joined: Dec 1999
Posts: 32,910
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Well,,,,,,,,,,,,,,,,,,,,,,,,,,,,, I don't think GM engineered a decoupler to scream like a sick eagle when decoupling. LOL and that play is a little much. So,,, Theres part of your issue.
Lets try this. Drizzle some heavy lube into the decoupler and work it in. (Note! This may destroy an already bad decoupler) See if the lube stops it from making noise but continues to couple in the driving direction. You can always flush out the lube with carb spray or brake parts cleaner.
Put the alternator back on and see if the noise is still there or gone.
As for the Power steering noise. Cant say for sure that I have ever experienced that noise. The pulley is PRESSED on the shaft so, if the shaft and pulley are loose, theres a BIG issue.
The pump has a check ball in it and that could be making the noise if the spring behind the ball is weak.
Bill
Lets try this. Drizzle some heavy lube into the decoupler and work it in. (Note! This may destroy an already bad decoupler) See if the lube stops it from making noise but continues to couple in the driving direction. You can always flush out the lube with carb spray or brake parts cleaner.
Put the alternator back on and see if the noise is still there or gone.
As for the Power steering noise. Cant say for sure that I have ever experienced that noise. The pulley is PRESSED on the shaft so, if the shaft and pulley are loose, theres a BIG issue.
The pump has a check ball in it and that could be making the noise if the spring behind the ball is weak.
Bill
Thread Starter
Cruising
Joined: Aug 2014
Posts: 13
Likes: 0
From: San Bernardino California
Thanks, Bill.
I have already have a new decoupler pulley on order prior to seeing your post. Additionally, I took the alternator to a rebuild shop to spin-up the armature and have a listen. It was noisy and they said I'd need a rebuild. Although I heard noise when they spun it, I'm not sure it was THE noise. Either way, I'll find out after this.
Alternator rebuild is costing $140 (including ADP).
They quoted me $170 for a PS pump rebuild.
And no the PS pulley isn't loose on the shaft. I think it's the ball you mentioned because it feels like that would feel (if you know what I mean).
I have already have a new decoupler pulley on order prior to seeing your post. Additionally, I took the alternator to a rebuild shop to spin-up the armature and have a listen. It was noisy and they said I'd need a rebuild. Although I heard noise when they spun it, I'm not sure it was THE noise. Either way, I'll find out after this.
Alternator rebuild is costing $140 (including ADP).
They quoted me $170 for a PS pump rebuild.
And no the PS pulley isn't loose on the shaft. I think it's the ball you mentioned because it feels like that would feel (if you know what I mean).
Last edited by petr0lb0mb; Oct 13, 2014 at 10:08 PM.