Oh no... something is wrong
 

After coming back from a weak long thanksgiving break, my car was completely dead. No doors open, lights on, or anything. I called AAA to give me a jump start and when it started there was a high squealing noise and slight growling (other than the V8) coming from the engine bay. The AAA guy told me to turn it off and explained to me that his theory of why my car died. He thinks that my serpantean (sp?) belt (high pitch noise) was slipping and it was going away when the engine was warm and the belt would catch and the growling noise was a bearing going bad in either the alternator or the water pump... just what I need. Does anyone have any experience with this and any estimate on how much this could possibly kill my wallet? Thanks for the help X5'ers.

How about going to the mechanic and getting a better idea than asking a forum?

If it's the serpentine belt, it's not expensive. It could be a bad alternator also, which explains the dead battery.

Bearing noise from an idler pulley is a cheap fix also.

But you're better off taking it to a mechanic since none of us online can hear the noise. :)

Well since you say the battery was dead, the alternator is most likely the issue. Many places, Advanced Auto for example, will test an alternator for free. I doubt the serp belt was slipping simply because, that is rare for a toothed serp belt.

When the 180 amp water cooled alternator gets old and goes out it sometimes locks up solid. I have seen people think they need an engine because of an alternator.

What I would do is remove the belt and turn all of the pulleys by hand to see which one(s) are funky.

Thanks for the tips. I am going to take it to a mechanic by the end of the week, I was just trying to get a heads up on what you guys think was wrong. I didn't want to get there and have them try to scam me into a $3,000 fix.

you can test the alternator yourself, if you're so inclined. hook at a volt meter to the battery leads.

With the motor running, the voltage should read around 14V. If it's lower, your alternator may be the issue.