Altenator Whine @ low rpm

[98LarsonGM57]

I don't recall how long it is been this way, but I have noticed or been more sensitive/suspecious of a whining sound that is audible at idle, and gets louder to about 1500 or so rpms and then dissipates.. not sure if the sound really stops or is just no longer noticable given the additional engine /whater noise.. <br /><br />Should i be concerned? It seems to be proucing pleanty of amps... <br /><br />Details: <br />1998 Larson<br />5.7L Volvo/SX - 2003 block. <br /><br />Thanks in advance for any thoughts...

 

[tommays]

Re: Altenator Whine @ low rpm

one of the bearings could be going bad they get noisey before they fail<br /><br />if you losen the belt and turn the altenator and water pump you may be able to tell were the rumble is comeing from<br /><br /><br />tommays

 

[98LarsonGM57]

Re: Altenator Whine @ low rpm

thanks tommays - that was what I was wonder, except it seems awfully high pitched... <br /><br />Is this a long process of going bad or should I freak out and replace the altenator asap?

 

[seahorse5]

Re: Altenator Whine @ low rpm

A faulty diode inside the alternator can also cause a whine noise, as can a bad bearing. Check the total amperage output of the alternator according to the service manual, and if it is much lower than the spec, then it could be a bad diode. Either way the alternator should be checked and serviced.

 

[tommays]

Re: Altenator Whine @ low rpm

i would first check it with the belt lose to see how it turns were just takeing a guess at this <br />point<br /><br />it should be cheap for a rebuild shop just to replace the bearings if bad<br /><br />if it feels bad i would do it it should be easy to take of on a sunday nite drop it off and put it back on the next weekend so you dont lose whats left of the season<br /><br /> much better than wating till it fails and your broken down<br /><br />tommays