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Discussion Starter #1
A noise is coming from the front of the engine... Its louder than it normally sounds. At idle and at higher speeds. I recorded the noise and compared it with other Users who posted to youtube and claimed it was their alternator bearings... However I removed the alternator, spun it... feels fine to me.. I've also hand spun all the other pulleys, all seemed just fine... The fan pulley has a little forward/backward movement. I replaced both belts the year before... the belts have about 7K miles on them. What is causing the noise?
 

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2006-2009 Range Rover MkIII / L322
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Think you're going to have to link your sound recording to get anything more than some wild guesses. Does it happen all the time, happen under load or hard acceleration, etc.
 

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Sounds kind of like a power steering pump whine, is it louder on the drivers side than the passenger side?
 

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It sounds almost like a bad alternator pulley..My Discovery sounded a bit more tame but at idle sounded similar. The pulley did in fact spin freely, when the engine was very warm the sound was quiet. I assume due to old grease in the bearing being 16 years old.

Hopefully last resort as they are quite pricey for an OE unit.


Sent from my iPhone using Tapatalk Pro


Edit.. last video sounds PRECISELY like my old alternator.....
 

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Discussion Starter #8
Its not the tension idler pulley on the secondary belt... I replaced it. I just talked to service at the Land Rover dealership... Based on the vehicle symptoms.. I told him I removed the alternator and spun the pulley.. and it was just fine.. he said it is most likely the alternator still, but its the diodes that are going out, not the bearing... the diodes will make the same high pitch sound and smell like something is burning... which I thought I smelled originally.
 

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FYI a good pulley shouldn't spin freely at all... It should turn, but with some resistance. If you go to spin it, and it spins around freely it is toasted. Also spinning them by hand is useless given there is no load on em.
 

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Range Rover MkIII / L322
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he said it is most likely the alternator still, but its the diodes that are going out, not the bearing... the diodes will make the same high pitch sound and smell like something is burning... which I thought I smelled originally.
This is fairly common with these alternators. A bad rectifier can produce a mechanical whine. You can buy after market rectifiers and they are fairly easy to replace. I have done 5 including one on my 2006 car.

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