Alternator or tensioner?
#1
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When I start my 95 X300 in the mornings I get a loud squeeling sound and the amp meter show little to no charge. A few blocks down the street the noise stops and the charge is at the 13+ amp mark. The local guy first thought belts so we replaced them but the noise was back the next day. Took her back and he thought tensioner pulley was bad but changed his mind because of the drop in charging; he now says its a bad alternator. Spraying belt dressing on the belts stops the noise and the charge returns to normal. So is it a bad altenator or a bad belt tensioner?
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#7
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Hey, Sean, since we saw you at your grandma's house, my 95 XJ6 A/C belt has started squealing. I bought new belts and am getting ready to replace them. Haven't found any info on how tight to adjust them, but it seems like A/C belt self tightens with the idler pulley. Don't know about alternator belt tightening. I'll try just tightening to the same spot as old belt, but may not work with new one, because of slight stretching with age. (tried to edit title to correct typo: problem )
Last edited by SteveL; 10-01-2012 at 12:34 PM. Reason: typo
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#8
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What are we all in the same boat? Mine just started to squeel in the morning. My crank damper has been replaced and all the belts. It just started this too, just like you people. Change in temperature? Just in the morning?
Doesn't go to the top of the repair list as my PO713 code is preventing driveability. Same mentioned in a previous post. I'm afraid a trans shop is going to rip me off.
Doesn't go to the top of the repair list as my PO713 code is preventing driveability. Same mentioned in a previous post. I'm afraid a trans shop is going to rip me off.
#9
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The required tension for each belt is listed in the service manual on the Jaguar Heritage CD. The tensions are expressed in Newtons and can be measured with a Burroughs gauge. If you have access to a Burroughs gauge but its calibrated in lbs force, then 1lbforce = 4.448Newtons. The belt tension is also expressed as its natural frequency, but unless you have a Clavis Meter you won't be able to measure its frequency. The tension in all the drive belts needs to be set manually. No auto-tensions are used.
BTW, if you need to remove a component and want to refit it with the same tension, then I would suggest counting the number of screw turns used to relax the tension to remove the belt, and then reapplying the same tension when the belt is refitted. However, this approach cannot be used when replacing an old belt with a new one because the old belt will have stretched. Adjusting the tensioner to the old position will resulting in a higher tension, even if the replacement belt is "nominally" the same length as the old one.
BTW, if you need to remove a component and want to refit it with the same tension, then I would suggest counting the number of screw turns used to relax the tension to remove the belt, and then reapplying the same tension when the belt is refitted. However, this approach cannot be used when replacing an old belt with a new one because the old belt will have stretched. Adjusting the tensioner to the old position will resulting in a higher tension, even if the replacement belt is "nominally" the same length as the old one.
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#12
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When I start my 95 X300 in the mornings I get a loud squeeling sound and the amp meter show little to no charge. A few blocks down the street the noise stops and the charge is at the 13+ amp mark. The local guy first thought belts so we replaced them but the noise was back the next day. Took her back and he thought tensioner pulley was bad but changed his mind because of the drop in charging; he now says its a bad alternator. Spraying belt dressing on the belts stops the noise and the charge returns to normal. So is it a bad altenator or a bad belt tensioner?
#13
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I have a 1996 xjr and the compressor belt just blew apart while driving. At the same time, the alternator belt has been slipping. I now get to replace all three belts. I was checking to see why the compressor belt would have blown apart, but I don't see anything wrong. I don't know how to take off the alt belt, is there a tensioner? I just see it around the alternator, a pulley near my supercharger, and the engine pulley. I just wonder why the alternator belt was slipping and why the brand new compressor belt broke apart. Any thoughts?
#14
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#16
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The required tension for each belt is listed in the service manual on the Jaguar Heritage CD. The tensions are expressed in Newtons and can be measured with a Burroughs gauge. If you have access to a Burroughs gauge but its calibrated in lbs force, then 1lbforce = 4.448Newtons. The belt tension is also expressed as its natural frequency, but unless you have a Clavis Meter you won't be able to measure its frequency. The tension in all the drive belts needs to be set manually. No auto-tensions are used.
BTW, if you need to remove a component and want to refit it with the same tension, then I would suggest counting the number of screw turns used to relax the tension to remove the belt, and then reapplying the same tension when the belt is refitted. However, this approach cannot be used when replacing an old belt with a new one because the old belt will have stretched. Adjusting the tensioner to the old position will resulting in a higher tension, even if the replacement belt is "nominally" the same length as the old one.
BTW, if you need to remove a component and want to refit it with the same tension, then I would suggest counting the number of screw turns used to relax the tension to remove the belt, and then reapplying the same tension when the belt is refitted. However, this approach cannot be used when replacing an old belt with a new one because the old belt will have stretched. Adjusting the tensioner to the old position will resulting in a higher tension, even if the replacement belt is "nominally" the same length as the old one.
#18
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I forgot to post after I solved my belt noise and alternator charging issue. It turns out that my harmonic balancer had come apart (the rubber damping components). I removed it, sent it to Damper Doctor in Oregon, I think it is, and got it back within 48 hours. Reinstalled it and it works like a charm; noise gone and alternator charging fine. I had to come up with a way to remove the old and torque the new, so I made a tool out of wood and used the harmonic balance removal tool rented from Autozone along with it. I took pictures of my tool, but basically it is a piece of 3/4" plywood long enough to seat against the engine frame to the drivers side of the damper with a fabricated round piece screwed onto it that fits inside the damper and the 2 bolts from the rented tool run though 2 holes in the wood and screwed into the damper holes. I braced it against the frame and bumped the engine. The whole thing flew off and I thought I might have broken something, but it flew off because it worked and loosed the damper bolt. I used it and a breaker bar to reinstall and manually tension the bolt afterwards. Cheap fix, but worked. I had to remove the fan shroud to get space, but that is super easy to remove and reinstall. Had to do it to replace alternator too, because the damn bolt at bottom is too long to get out without removing fans.
#19
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