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Discussion Starter · #1 ·
Died in the middle of a busy intersection. Then, the fraking battery light came on! It would have been nice if the battery light came on BEFORE I got stranded. What POS electronics!
Waited for 60 minutes for BMW Assist to get a tow truck to me, another 45 minutes to load it up and take it to the dealer where we left it unlocked since the door locks refused to work anymore. So, the whining noise must have been the alternator. Why did not warning lights show up? I thought something electrical was going on because all the computer settings would reset overnight.
 

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Had something very similar happen to me in a 993. When it finally went all of the warning lights started started to illuminate and shortly thereafter the car just died.
 

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Unfortunately the engine management systems have not been assigned the job of watching the battery. They do monitor alternator output, but NOT battery state of charge. Your alternator was doing its job and making the juice so no warnings were triggered. The battery could not store the juice so the car died. You need a new battery. There is a possibility that your alternator is shot by now because it has been working like a bastard pumping electricity into a battery which would not hold it.
Should all be warranty work. BMW did not make the battery if that's any consolation to you.
 

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Discussion Starter · #7 ·
Yes, sounds like what happened to my car

Had something very similar happen to me in a 993. When it finally went all of the warning lights started started to illuminate and shortly thereafter the car just died.
the dash looked like a xmas tree with all the lights blinking.
 

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Discussion Starter · #8 ·
How is that possible?

Unfortunately the engine management systems have not been assigned the job of watching the battery. They do monitor alternator output, but NOT battery state of charge. Your alternator was doing its job and making the juice so no warnings were triggered. The battery could not store the juice so the car died. You need a new battery. There is a possibility that your alternator is shot by now because it has been working like a bastard pumping electricity into a battery which would not hold it.
Should all be warranty work. BMW did not make the battery if that's any consolation to you.
New battery (6 mos). Never left lights on to drain it. Plus, I had the whining noise from the engine compartment for the last 3 days which I thought were the turbos (sounded very similar to that youtube video showing the turbos with the bad bearings). Well, the car is at the dealer now. Let's see what they find.
 

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I had a battery die in a SAAB out of the blue and the car acted like it had lost its mind, but there was no forewarning. All of a sudden bells started going off, the driver's seat started moving on its own, a rear window went down and the door locks started clicking over and over again, and then it was dead. New battery and it was good as new, but then that battery was 2 years old (still premature for a modern battery, IMO).
 

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Forgot to mention that the cure for the 993 was a new alternator. Yes the dash did look like a Christmas Tree. Not knowing what the problem was I had the car jump started only to get stranded again before I could make it to my house. Thanks AAA
 

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Discussion Starter · #11 ·
Yeah, but did the 993 only have 3300 miles on it like my 335xi did?

Forgot to mention that the cure for the 993 was a new alternator. Yes the dash did look like a Christmas Tree. Not knowing what the problem was I had the car jump started only to get stranded again before I could make it to my house. Thanks AAA
VERY unusual. The word I got from my SA was "these cars are by no means bulletproof and they are the cause of all my stress, I had HPFPs fail in cars with less than 500 miles on them". But, he says the majority of HPFP failures were in the 07s although some 08s may occasionaly get HPFP failures. The reason HPFP failure came up is that was the first thing that the SA thought when they saw my disabled car in their lot this morning :)
 

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if batt would not hold charge, did you notice the car not cranking/starting easily
 

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Discussion Starter · #14 ·
No, car operated fine until it died

if batt would not hold charge, did you notice the car not cranking/starting easily
Only noticeable issue was a whining noise and some of the computer settings would reset overnight. (time, mpg, etc).
 

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Only noticeable issue was a whining noise and some of the computer settings would reset overnight. (time, mpg, etc).
The whining noise was the alternator busting a gut trying to recharge a system which was probably shorted. You have a new car in which the battery was already changed once? Something is going on here. My feeling is that the dealer is going to replace both the alternator and the battery. They then should do a charging test to ensure the battery is not being overcharged. The ECM commands alternator output based on battery charge state. If the battery shorts (internally) then the ECM reads the low voltage and commands full alternator output. You sure don't want this to happen again in a few months and that's why very thorough testing needs to be done AFTER the car is 'fixed'. The tech assigned to the job may not get sufficient time for diagnostics: he needs to be paid for not only figuring out what is wrong with your car now, but also what CAUSED the problem.
 

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By any chance, have you made ANY electrical modifications? Even of the slightest kind? Headlamp bulbs? Amplifier? Hardwired cell phone or MP3 adapter? Anything at all?
 

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Discussion Starter · #18 ·
Hmm, did I make it sound like the battery was changed? No it has not been changed

The whining noise was the alternator busting a gut trying to recharge a system which was probably shorted. You have a new car in which the battery was already changed once? Something is going on here. My feeling is that the dealer is going to replace both the alternator and the battery. They then should do a charging test to ensure the battery is not being overcharged. The ECM commands alternator output based on battery charge state. If the battery shorts (internally) then the ECM reads the low voltage and commands full alternator output. You sure don't want this to happen again in a few months and that's why very thorough testing needs to be done AFTER the car is 'fixed'. The tech assigned to the job may not get sufficient time for diagnostics: he needs to be paid for not only figuring out what is wrong with your car now, but also what CAUSED the problem.
By new battery I meant that it's relatively new like the car itself. About 6 months old.

But, good points all around. The only thing that's permanently "plugged in" is my GPS and it's plugged into the lighter port. The car is bone stock.
 

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Discussion Starter · #19 ·
Dealer just called. Said, "Shot alternator"

More info tomorrow after the new alternator is put in then they will run some tests.
 
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