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Discussion Starter · #1 ·
I have a feeling that my alternator is making a weird noise at idle.

Is it possible for the bearings to go bad on an alternator but have the alternator work perfectly? (voltage-wise)
 
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Yes. Is definitely coming from the alt? Take a stethoscope and listen... Or a really long screwdriver if you don't have one
 

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Discussion Starter · #3 ·
Yes. Is definitely coming from the alt? Take a stethoscope and listen... Or a really long screwdriver if you don't have one
The power steering pump, tensioner pulley, idler pulley, and water pump have been replaced. So has the alternator, but it was refurbished, and the noise started aroudn the time I replaced it...
 

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When you did all this work, did you replace the belt? If not, did you remember to put the belt back on the same direction it was on before?

Also, since I just learned myself...it's possible to install an alternator but not have it installed correctly. Somehow, without realizing it, I managed to put my alt back after an ofhg diy without the bolt for the idler pulley going through the side tab on the alt. It held there for months until my mechanic noticed it while checking stuff out. So double check that as I know its possible...and I also know that so many have had issues with getting alt in. Me? I thought it was easy; now I know that might be coz I did it wrong...not saying you did...but it's possible.

Also, my stethoscope is a 5' hose and can help you isolate sound without having to actually put anything like mech's steth or screwdriver on moving parts...a little safer for you with hose, I think. A refurbished alt should be good, though I honestly don't think they'd replace the bearings, but just the brushes and VR...but I really don't know for sure.

HTH...have a listen around...and good luck!
 

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The power steering pump, tensioner pulley, idler pulley, and water pump have been replaced. So has the alternator, but it was refurbished, and the noise started aroudn the time I replaced it...
I have the same issue as you. I had both tensioners, idler pulley, water pump pulley, and belts replaced 6 months ago. It was quiet for a few months and then the cricket-like noises starting re-appearing. When I did the OFHG replacement, I spun the alternator pulley, and it matched the cricket noise caused by bad/dry bearings. I have 132k on my orig. alternator. So I bought a re-manufactured alternator since I really don't want to take parts out again in another few months when the alt. craps out.
 

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Discussion Starter · #6 ·
Well i am taking the car to a repair shop on Tuesday. I am done guessing. I'll let you guys know what I find out. The alternator is in the slot correctly, and I've had it in and out 3 different times since the initial install. Turning the pulley with no load does not make a sound...

I am also asking the repair shop to look for vacuum leaks and pressure test my power steering hoses. It's not a BMW certified mechanic shop and honestly I am kind of scared to let them touch the car, BUT the nearest certified mechanic is over 6 hours away from me (That's gotta be some kind of record right?)

Thanks for the input!
 
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