A/C belt walking off Compressor
Thread Starter
Instructor
Joined: Feb 2011
Posts: 140
Likes: 24
From: Houston Texas
A/C belt walking off Compressor
Hi Guys,
About 3 weeks ago I replaced both a/c belt pulleys and the belt itself due to squealing. I did not replace the actual ac belt tensioner. Saturday night when I started the car up it was knocking, squealing, and raising all kinds of hell. When I opened the hood I noticed the ac belt had walked forward 1 groove off the a/c compressor.
When I put it back on correctly and restart the car the belt walks forward one groove again. If the accessory belt was walking forward too I would suspect the harmonic balancer was toast, but the accessory belt is fine.
Has anyone had this problem or know what the root cause might be? I don't get why everything was perfect for 3 weeks and now all of a sudden I have a belt that wants to come forward off the pulley on the ac compressor. Any advice would be greatly appreciated!
About 3 weeks ago I replaced both a/c belt pulleys and the belt itself due to squealing. I did not replace the actual ac belt tensioner. Saturday night when I started the car up it was knocking, squealing, and raising all kinds of hell. When I opened the hood I noticed the ac belt had walked forward 1 groove off the a/c compressor.
When I put it back on correctly and restart the car the belt walks forward one groove again. If the accessory belt was walking forward too I would suspect the harmonic balancer was toast, but the accessory belt is fine.
Has anyone had this problem or know what the root cause might be? I don't get why everything was perfect for 3 weeks and now all of a sudden I have a belt that wants to come forward off the pulley on the ac compressor. Any advice would be greatly appreciated!
Instructor
Joined: Jan 2007
Posts: 181
Likes: 0
From: Houston Texas
Silly question, but is the new pulley installed the right way? I think the only way for the belt to want to walk forward is if the pulleys are misaligned. Find out which one is too far back (compressor) or if the other is too far forward.
Team Owner
Joined: Jul 2012
Posts: 34,479
Likes: 532
From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
My idler had wear, and my tensioner was shot, and that made mine do the same thing. Be warned, the belt is most likely toast now. Mine cut the belt where the 1 rib had run up on the larger diameter part of the pulley. I found it easier to see the pulley issues from under the car.
Instructor
Joined: Jun 2011
Posts: 165
Likes: 3
From: Cave Springs Arkansas
I replaced pulleys & tensioner on my '01. Went back a week later to re-torque bolts & one had loosened a little. You might check & see if this happened to you, also.
I would replace tensioner, too...
Good luck.
I would replace tensioner, too...
Good luck.
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
I think your harmonic balancer is bad. Because the drive belt is much longer, it has more forgiveness. the AC belt is much shorter and when the HB moves forward it pushes the belt up one rib.
FYI, if you don't address it quickly, you can damage the engine. Typically the elastomer on the HB starts to break down ( become degraded) causing the outer rib on the balancer to detach from the center hub. At first it is slight, ( enough to throw the belt off a rib )but quickly escalates.. In my opinion, the HB is telling you something. Another tell tail sight is smelling of burning rubber or seeing pieces of rubber where you park on the ground under the motor.
FYI, if you don't address it quickly, you can damage the engine. Typically the elastomer on the HB starts to break down ( become degraded) causing the outer rib on the balancer to detach from the center hub. At first it is slight, ( enough to throw the belt off a rib )but quickly escalates.. In my opinion, the HB is telling you something. Another tell tail sight is smelling of burning rubber or seeing pieces of rubber where you park on the ground under the motor.
Safety Car
Joined: Nov 2002
Posts: 4,394
Likes: 6
From: Melbourne FL
I think your harmonic balancer is bad. Because the drive belt is much longer, it has more forgiveness. the AC belt is much shorter and when the HB moves forward it pushes the belt up one rib.
FYI, if you don't address it quickly, you can damage the engine. Typically the elastomer on the HB starts to break down ( become degraded) causing the outer rib on the balancer to detach from the center hub. At first it is slight, ( enough to throw the belt off a rib )but quickly escalates.. In my opinion, the HB is telling you something. Another tell tail sight is smelling of burning rubber or seeing pieces of rubber where you park on the ground under the motor.
FYI, if you don't address it quickly, you can damage the engine. Typically the elastomer on the HB starts to break down ( become degraded) causing the outer rib on the balancer to detach from the center hub. At first it is slight, ( enough to throw the belt off a rib )but quickly escalates.. In my opinion, the HB is telling you something. Another tell tail sight is smelling of burning rubber or seeing pieces of rubber where you park on the ground under the motor.
HB is the most likely cause of your problems.
Thread Starter
Instructor
Joined: Feb 2011
Posts: 140
Likes: 24
From: Houston Texas
Well I replaced the entire belt tensioner. When I looked at the old part I could see where the bearing inside the aluminum housing had worn off center causing the assembly to wobble around the bolt going into the engine block. I knew I should have just replaced the whole tensioner instead of trying to save a dollar by just replacing the pulley.
By some stroke of luck the belt is a-okay. I watched the harmonic balancer closely looking for a wobble or out of balance rotation and didn't observe one so I think I'm in the clear on that. It will be replaced in the near future though when I have my supercharger installed.
Thanks everyone for the suggestions and comments!
By some stroke of luck the belt is a-okay. I watched the harmonic balancer closely looking for a wobble or out of balance rotation and didn't observe one so I think I'm in the clear on that. It will be replaced in the near future though when I have my supercharger installed.
Thanks everyone for the suggestions and comments!
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