[starquestbd22]

Hi all. My 2004 hemi has a pretty loud whining sound originating from the front of the engine. It also has a slight mechanical (very light metal on metal maybe) sound if you listen closely but the whine is by far the most pronounced. I raised the hood and it immediately draws your attention to the alternator but I noticed that the water pump (I think, it was a quick look) and an idler pulley/tensioner are very near the alternator so even though it sounds exactly like it is coming from the alternator it very well could be one of the other two. I may replace the belt anyway but I do not think it is the belt.

Am I correct that the water pump is located just below and maybe to the left if I remember correctly from the alternator? Any thoughts on how I can diagnose which one is making the noise? The temp seems to run perfectly normal. I don't want to replace the alternator needlessly (even though I guess I could return it if it didn't fix it) because the [email protected]#* thing is $175!! Thanks in advance!

 

[Maddevill]

A little wine....

You can take a metal bar like a extension for a ratchet wrench and put it next to the unit you want to listen to. Put the other end to your ear and if the thing is making noise you should be able to hear it clearly through the bar. be careful not to get it into a moving part. Move it around and listen to various components and you'll get a better idea of what it could be. Or you can buy a mechanic's stethoscope too.:smileup:

 

[starquestbd22]

I did some more looking/listening and tried the metal bar to see if I could isolate it. I'm fairly confident that part if it is the alternator but it almost sounds like one of the other pieces may be making a noise as well. It's really hard to tell over the other engine noises. I see now that what I originally thought was the water pump pulley is actually just an idler pulley located right under the alternator. It also has the belt tensioner and its pulley tucked into the same area. I believe the noise(s) is/are coming from one or a combo of these three parts. It looks like the tensioner pulley and the idler pulley are available as separate parts so I will probably start there and see where that gets me. Any other thoughts?

 

[starquestbd22]

Got some free time and a nice day yesterday so I took the serpentine belt off and rotated everything by hand. After that I was even more confident it was coming from the alternator. Replaced it and waaa-laaaaa, fixed!