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Alternator???

3905 Views 19 Replies 8 Participants Last post by  6shooter
Lately, I've been having this whine/squeal coming from the engine bay. My dad and I pulled the belt of because he thought it could have been the water pump, again, but when we spun it, we couldn't hear anything. He thought it could have been the tensioner pulley. Took it off, spun it, and you could hear the bearings inside just moving around. So we changed that out, sound went away. Now it's back. Didn't even take a day for it to return. So, we went back and looked to see what it was. My dad said it sounds like it's coming from the alernator. When you touch it while the engine is running, you can feel a rhythm that matches the sound.

Something else, it only does it when it's in R,N,D, but not park. It also stops when I'm on the highway and it hits the "cruising" gear.

PS: We have kinda ruled out the water pump, but not completly. When it went out last time, when I turned the car on, it would squeal. No matter what speed I was going, it would squeal. Even in the "cruising" gear.

Hoping for any input from you guys. Thanks!

PPS: Sorry if it sounds sloppy. I'm a little tired right now.
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Do you have any performance issues related to the alternator? Dimming lights under load? You could take some silicone spray and shoot it into the alternator to see if the squeal goes away. It could also be a belt squeal that only presents when the engine is under load. Spray a shot of belt dressing and see if it goes away. If you don't have any take bar soap and hold it against the pully side of the belt while the truck is running.
The only time my lights dim is when I got my music turned up loud and my amp is pretty much taking all the power to it. I don't have any silicone spray, but I will try the soap on the belt.

Now, lets just say it is the alt., will any alt. work from any 5.2/5.9 engine?
Yes they interchange but electrical connectors might be different from other years. I guess you could shoot some wd-40 or other spray lubricant into the alternator to test it if you have it but I would not spray alot.
Any alternator from a 3.9, 5.2, 5.9 will work.
I've got one I'll sell you for $60 shipped if you're interested. From a 2000 model.
Remember though, every alternator from a 3.9/5.2/5.9 may work, but they came at different amperage ratings. By the sounds of it, you'll want a higher one. (I dont remember the specific amps)
The one I have for sale is a 136 amp ..... if you want I can take pics of the connections
fuck where were all these people selling them when I needed one? haha I just got one from Vatozone today and changed mine out. Including driving time to get the new one and shit it was like a 2 hour job, and that included breakfast break haha

Still had the squeak after... Check the belt too, go buy a Napa gold series belt for like $50, I am on my 3rd as they come with a lifetime warranty. Mine needed to be changed as well.
Well I've found some at junkyards for around $30, but I didn't check what amp rating they were at. And those were only coming off of Durangos.
My belt has around 30k on it right now. We just are not exactly sure what it is, but right now we do think it is the alernator.
you could get yours rebuilt..... new bearings and other internals, would be just like a reman one...

and just because your belt doesn't have 30K on it doesn't mean it isn't time to replace it. If something like a pulley is off balance or the bearing is bad, or the tensioner isn't putting the correct tension on it, it WILL make the belt go bad much faster. I am on my 3rd belt in about 30K total. First one didn't last more than 5k (because of a bad tensioner) second was just replaced because of a bad bearing in the alternator... can't just assume its fine.
What about the fan clutch? Has anyone had that go out on them? My dad seems to think that might be what it is.
haha wow its like your having EVERY issue and thought I just did haha. My fan in the front has a slight, very slight wobble too it, I was also thinking that could be the issue. Go in order of least expensive to the most haha. Pull the fan off the front, then change the belt, then change the alternator
It is odd it doesnt do it in Park. Those tranny's dont pump fluid in park...
So, are you suggesting it's my tranny?
I'll have to get a video of it tomorrow so you guys can hear what it sounds like.
its hard to say...take the serp belt off when its cold, then start it up, that way you can see if its the alternator... But if it goes away in park and overdrive i would be suspicious of something else.
does it do it any worse or better when you turn on the lights, heater fan, etc? mine in my 98 went and would squeal when you put it under heavy electrical load only. (wipers on, headlights on, heater fan all at once) then it went away when i hit cruisin speed. just a thought. but the "not when its in park" thing is kind of fishy.
@lowlife: I'll take the belt off tomorrow to see if it does it or doesn't.

@6shooter: I haven't noticed much difference in sound under heavy electrical load or not. I'll listen closely tonight, then listen tomorrow on my way to school to see if there is any difference.

Also, it does stop slightly when I hit crusing. I'll listen to that also to give you guys a better description of the sound.
OK, so I did not really notice any difference in noise while having the lights on, wipers on, stereo on etc. One thing I did notice though is that when I turned my rear defrost on when I had my dome lights on, they dimmed, then went back to normal. So I'm guessing it is the alternator going out on me.
noisey alts are a common problem and it doesn't mean there's anything wrong....mine has been chuggin' along for 6-7 years now with the noise.....the clutch fan(if you still have it) can make some weird noises as well.
noisey alts are a common problem and it doesn't mean there's anything wrong....
i doubt its squealin like mine was when it went out, then. mine sounded like a wet fan belt screamin in your face whenever you'd put a heavy electrical load on it, and that does mean somethings wrong. its the bearings takin a crap in the alt
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