Squealing like a pig
Thread Starter
Melting Slicks
Joined: Jan 2006
Posts: 3,180
Likes: 297
From: Sarasota Florida
Squealing like a pig
I'm stumped. Most days when I start my '71 BB, I get a squeal from somewhere on the front of the motor. It goes away after a minute. But, when I turn on the Vintage Air, it squeals constantly. I've played with belt widths and tension to no avail but it does go away if I remove the AC belt. You'd suspect the compressor bearings or something like that but no. With my stethoscope, I get no hint from the waterpump, AC, or power steering pump. It's as if the added load of the compressor being on creates a load somewhere else on the system.
It's a long shot, but could it be the fan clutch?
The last answer I want to hear is loose crank pulley... I do see a slight wobble.
What say the experts?
It's a long shot, but could it be the fan clutch?
The last answer I want to hear is loose crank pulley... I do see a slight wobble.
What say the experts?
Le Mans Master
Joined: Jun 2006
Posts: 6,400
Likes: 1,226
From: Tampa Florida
I'm stumped. Most days when I start my '71 BB, I get a squeal from somewhere on the front of the motor. It goes away after a minute. But, when I turn on the Vintage Air, it squeals constantly. I've played with belt widths and tension to no avail but it does go away if I remove the AC belt. You'd suspect the compressor bearings or something like that but no. With my stethoscope, I get no hint from the waterpump, AC, or power steering pump. It's as if the added load of the compressor being on creates a load somewhere else on the system.
It's a long shot, but could it be the fan clutch?
The last answer I want to hear is loose crank pulley... I do see a slight wobble.
What say the experts?
It's a long shot, but could it be the fan clutch?
The last answer I want to hear is loose crank pulley... I do see a slight wobble.
What say the experts?
2. You mentioned a slight wobble. Did you check the 3 bolts that secure the crank pulley to the harmonic balancer?
3. Another wobble theory, do you have the correct water pump shaft size (3/4")? A 5/8" wp shaft will work, but it causes a strange vertical wobble with the 3/4" water pump pulley. I know this one from experience.
So how did the body repair turn out?
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
So can you isolate the squeak to the actual AC pulley when the belt is on? or are you saying the squeak comes from a different pulley but with more intensity with the AC on?
I would be tempted to get a different brand and or dimension of belt for the AC. The V shape on the belt may be too narrow allowing it to sit in the bottom of the pulley groove allowing it to slip.
I would be tempted to get a different brand and or dimension of belt for the AC. The V shape on the belt may be too narrow allowing it to sit in the bottom of the pulley groove allowing it to slip.
Pro
Joined: Feb 2017
Posts: 518
Likes: 365
From: San Diego
2023 C3 of the Year Finalist - Modified
Not expert here, but I will throw something out there based on personal experience. Startup squeals for me have been the alternator belt as it tries to tries to charge from starter draw. Does your vintage air setup include electric fans that load the alternator? Wild shot here. Now I can let the experts chime in....
Thread Starter
Melting Slicks
Joined: Jan 2006
Posts: 3,180
Likes: 297
From: Sarasota Florida
So can you isolate the squeak to the actual AC pulley when the belt is on? or are you saying the squeak comes from a different pulley but with more intensity with the AC on?
I would be tempted to get a different brand and or dimension of belt for the AC. The V shape on the belt may be too narrow allowing it to sit in the bottom of the pulley groove allowing it to slip.
I would be tempted to get a different brand and or dimension of belt for the AC. The V shape on the belt may be too narrow allowing it to sit in the bottom of the pulley groove allowing it to slip.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
If you can get the squeak going and keep it squeaking then go and spray some WD40 silicone lube on one belt at a time you might at least be able to isolate it to a specific belt or pulley by aiming at the suspected pulley/belt first.
I've used the silicone spray before to eliminate belt squeaks and it works really well, so it should work well in isolating which one and from where it's originating.
I've used the silicone spray before to eliminate belt squeaks and it works really well, so it should work well in isolating which one and from where it's originating.
Le Mans Master
Joined: Jun 2006
Posts: 6,400
Likes: 1,226
From: Tampa Florida
Can you post a picture of your belt setup?
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Race Director
Joined: Mar 2017
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From: Virginia
Not expert here, but I will throw something out there based on personal experience. Startup squeals for me have been the alternator belt as it tries to tries to charge from starter draw. Does your vintage air setup include electric fans that load the alternator? Wild shot here. Now I can let the experts chime in....
Can you post a video while someone else starts the car? You can create a YouTube account very quickly, and a link from a video will appear inline in the Forum, making it easy to get lots of expert eyes on the problem (and mine and @Vibguy's, too
).
Thread Starter
Melting Slicks
Joined: Jan 2006
Posts: 3,180
Likes: 297
From: Sarasota Florida
Well here we go. With nothing to loose, I sprayed the water pump pulley with WD40. Instantly I saw the pulley continue to spin, but the AC belt was intermittently slipping... like the compressor was locking up. With the AC belt off (and the motor off), I couldn't rotate the compress by hand. Hmmm. I bled a lot of freon from the system and damn, I could freely turn the compressor. I put the belt back on, started it, and the squeal was gone. Surprisingly, the AC was still blowing cold. As all good Americans know, more is better, but I think I'll let a shop charge the system properly.
I still can't explain why the squeal occured at startup with the AC off, but I'm happy.
Thanks for all your inputs and 71 Green, here's a vid of the belts. https://photos.google.com/photo/AF1Q...SpnABmjnAWeMuD
I still can't explain why the squeal occured at startup with the AC off, but I'm happy.
Thanks for all your inputs and 71 Green, here's a vid of the belts. https://photos.google.com/photo/AF1Q...SpnABmjnAWeMuD
Instructor
Joined: Jan 2008
Posts: 149
Likes: 8
From: Scarborough Qld
Not sure if this will help as I can't access your link to the photos to see.
But.
On my Dads 71 454 a mechanic installed an after market air con system. He routed the belts from the compressor in "parallel" to the alternator (I think).
It would squeal every now and then with the air con off, but when the air con was on, the extra load would shred the belt. Dad replaced heaps of belt until another mechanic figured out the the belts running between the crank & water pump were "competing with one another, almost like one gaining on the other. Once they re-routed the belts, it fixed everything.
I hope this might help.
Cheers
Andy
But.
On my Dads 71 454 a mechanic installed an after market air con system. He routed the belts from the compressor in "parallel" to the alternator (I think).
It would squeal every now and then with the air con off, but when the air con was on, the extra load would shred the belt. Dad replaced heaps of belt until another mechanic figured out the the belts running between the crank & water pump were "competing with one another, almost like one gaining on the other. Once they re-routed the belts, it fixed everything.
I hope this might help.
Cheers
Andy