Serpentine belt keeps walking off
Thread Starter
Instructor
Joined: Apr 2007
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From: austin tx
Serpentine belt keeps walking off
For some reason my serpentine belt keeps walking off like half an inch toward the end of the harmonic balancer everytime I start the engine but have to keep putting it back in place. My harmonic balancer isn't shaking like wobbling but could that be the problem? Thanks guys
Team Owner
Joined: Jul 2012
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From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
Most likely you have an idler pulley that's in need of replacement. Check the tensioner also. Look close, you can see when they're out of line.
Team Owner
Joined: Jul 2012
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From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
Fyi, if you have ramps, or a lift, I found it easier to get a good look at the pulleys with the belt off and from underneath the car. From there, you could line up the balancer with the others and it was pretty obvious the idler/tensioner were not straight. Much easier to see than from above because the alternator tends to hide the tensioner some and especially that idler.
Thread Starter
Instructor
Joined: Apr 2007
Posts: 225
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From: austin tx
It dosent look aligned right with the rest of the pullies. I think the balancer might have moved back some I think. Wish I could take a pic guys, sorry.
Also the belt is moving "forward" is what I meant to say while I start the car every time I align it.
Also the belt is moving "forward" is what I meant to say while I start the car every time I align it.
Last edited by 04 Torch Red Vert; Jan 2, 2013 at 09:55 PM.
Team Owner
Joined: Mar 2001
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From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Harmonic balancer failure.. the rubber elastomer is coming apart allowing the balancer to move forward.. soon you will loose the front crank seal and right after that you will loose the motor.
Thread Starter
Instructor
Joined: Apr 2007
Posts: 225
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From: austin tx
scared now lol. I have another car so its in the garage for now. Looks I will have to take it to the dealership 
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Team Owner
Joined: Jul 2012
Posts: 34,479
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From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
Find a repair shop. A dealership is going to bend you over for this job. Prepare for some serious sticker shock otherwise. The job will require some considerable time, and a few special tools. Anybody who's done them before will be fine, but get someone who gives you a warm fuzzy feeling that they know their stuff. This is a job you don't want messed up. And going to a dealership is no guarantee it won't be.
Racer
Joined: Feb 2004
Posts: 359
Likes: 7
From: St. Paul MN
Tell yourself it's "good news" that you caught it in time. Maybe consider co-opting the majority of the labor charges to upgrade the cam if you have the inclination. Although it can quickly roll into a bigger project with heads, springs, tune, etc. I did mine last winter and put on a new harmonic balancer to "restart the clock" on the elastomer. Enjoying the extra 50+ HP tho! Good luck.
Todd
Todd
Team Owner
Joined: Jul 2006
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From: Kannapolis NC
Quick question to try to help the OP. Is it possible the bolt has loosened and the pulley is moving forward? I'm not sure from the description he gave "moving back" whether he means toward the block or toward the steering rack. If it's toward the block, the bolt would not be the issue. I know they have to be torqued and some have pinned, but is it possible he just needs a new bolt and torqued properly since it's not wobbling?
Le Mans Master
Joined: Mar 2011
Posts: 6,835
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From: Columbia SC
What I have heard on the forum says the balancer bolt is a one time use design. If it is loose you would need a new one,don't just retorque. If I am wrong, someone please correct me, I have not validated this with my factory manual.
Team Owner
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From: Kannapolis NC
You mean like in my last sentence in post #12 above?
Thread Starter
Instructor
Joined: Apr 2007
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From: austin tx
Quick question to try to help the OP. Is it possible the bolt has loosened and the pulley is moving forward? I'm not sure from the description he gave "moving back" whether he means toward the block or toward the steering rack. If it's toward the block, the bolt would not be the issue. I know they have to be torqued and some have pinned, but is it possible he just needs a new bolt and torqued properly since it's not wobbling?
Drifting
Joined: Jan 2012
Posts: 1,341
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From: Hopatcong New Jersey
The only way your harmonic balancer is going to "move back" is if it is separating. Also, it doesn't have to move anywhere for the belt to walk forward on it, this could also be caused by one of the idler pulleys or tensioner pulleys being misaligned. Before spending $800-1300 to replace a crank pulley I would first be absolutely sure THAT is what the problem is...The fact that the balancer isn't wobbling makes me question whether it is loose or seperating.
Team Owner
Joined: Jul 2006
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From: Kannapolis NC
I don't know how it can move in that direction. As suggested by others, check the alignment of all the pulleys. If it's only the balancer that's off line, I'm not going to suggest you change it until you get someone more knowledgeable than me to look at it in person. It would seem rare for it to seperate equally all around and move toward the block without having a wobble. Good luck with finding the cause.
Drifting
Joined: Jul 2005
Posts: 1,484
Likes: 27
From: Torrance Calif
This is a common problem with the MB 320 series.
Except in that the outside ring separates from the rubber and tries to go through the hood!
Except in that the outside ring separates from the rubber and tries to go through the hood!
Last edited by heavymetals; Jan 3, 2013 at 04:06 PM.
Team Owner
Joined: Jul 2012
Posts: 34,479
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From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
I don't know how it can move in that direction. As suggested by others, check the alignment of all the pulleys. If it's only the balancer that's off line, I'm not going to suggest you change it until you get someone more knowledgeable than me to look at it in person. It would seem rare for it to seperate equally all around and move toward the block without having a wobble. Good luck with finding the cause.
Thread Starter
Instructor
Joined: Apr 2007
Posts: 225
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From: austin tx
Well I wanted to update you guys about my car. Just got the call this morning from my dealership and said the harmonic balancer went bad but water pump was leaking which was a bonus but both covered under warranty, yayyyy. Was going to cost me about $1100 but have a $200 deductible which is even better. Thanks guys