alternator on the way out??

hey guys..i have a developing problem...something, when i start up in the cold, is really whistling, it gets faster with my revs and it sounds (try not to laugh) like my cherokee is making boost...but! no forced induction here so unfortunatly i kno its an issue...i dotn feel any loss of power and ive had 3 xjs and all do this do some extent but this one is bad...is this noise the alternator? i had Autozone check it last week and he said the alternator seemed to be in good shape, not new but not dying, but he added that my results could have been a little off because of the deep cycle optima batt.

today on the way to school i was heading up doing around 65 and my speedo and tach just fell...every other gauge was fine but less then a minute later the speedo and tach jumped back up...WTF!!??

any one have any incite..id appreciate it
Andrew

Well sounds like my problem, mine is the alternator, I removed the belt, fired her up for a sec to eliminate the engine from the equation, no noise, then I spun all the pullys by hand and my alternator made a similar noise. The autozone guy either didnt understand you or has no clue, from the sound of it he check to see if it was charging etc but its the sealed bearings inside that are going and will cause it to fail.... so its a perfectly good alternator in the sense that it puts out the desired amps but its bearings are falling apart and the only way to check them is to take the belt off to make sure its the alternator, not one of trhe other accesories or idlers

so how long do u think untill my alt. takes a sh!t?

You'll know the s.o.b is going at night when you step on the gas and your lights get brighter. It does sound like a supercharger though... Funny stuff... Who knows when it goes... Mine just decided not to start one morning...

LilRhodyXJ said:

so how long do u think untill my alt. takes a sh!t?

Click to expand...

Until the bearings fail. Problem is, there's no way to tell.

Sounds like it's time to upgrade anyhow...

5-90

should i get a junkyard one, by a new oem, or buy one of those upgraded ones out of quadratec?

Andrew

Napa sells a 160 amp unit for around 120

LilRhodyXJ said:

should i get a junkyard one, by a new oem, or buy one of those upgraded ones out of quadratec?

Andrew

Click to expand...

Click the link in my sig, and go to San Jose Generator. His prices are a bit better than just about everyone else, and you'll be talking to the guy doing the work...

5-90

so 5-90 i have a 2000 which is a nippondenso..so if i want a more powerful alt. i should get the 130 instead of the 90??

Ayuh. Check with Rod to make sure he can't do something even stronger for you (he might! I've got a 180A Delco he did on a "special...") and you're going to have to deal with him directly anyhow.

Do make sure you specify that you have a 2000 - there were some very minor changes over the years. The price didn't change, but some of the cosmetics did.

5-90

So did it turn out to be the alternator bearings that were your problem?

I've always had a slight whine to mine, even at idle. But lately, it's gotten louder....especially since it's turned off cold.

I first fire it up on a cold morning and it's whistling pretty good. Step on the gas and the whistle goes up, and it does sound kinda like a super charger. Once the engine gets warmed up it doesn't seem to be as loud, but it's still there, and more noticeable at slow speeds, generally under 10mph.

The other night I was driving in a cold rain and had both defrosters going, and noticed that driving down the road the volt meter showed a constant 14 volts. When I got off the highway and still had the defrosters on, the volt meter was showing about 11-12 volts. If I cut the blower up on high it would dip down to about 9-10 volts....any more and i'm sure the check guages light would have come on. Now I under stand both defrosters, especially with the blower on hi, will put a load on the system, but I never remember it being that much. I also noticed that sitting in the parking lot doing this test if I gave it gas while under that much load, the whine was REALLY noticeable. All this was after an hour trip on the highway, so everything was good and hot.

I can take a video of it in the next couple of days to show yall what i'm talking about. Don't need this thing takin a crap on me now.