E46 318i (2002) Battery Light

[sPoNgE-SA]

Hi all,

For the last week my battery light comes on Intermittently. My revs drop and complete loss of power for a second and then battery light comes on and then comes off right away. The battery was charging at 16Volts so I had the alternator replaced/ Charging is fine but the problem has come back, I have had my car tested. The guys I go to only work on BMW's, the head mechanic drove around with me so I could show him the problem but it failed to happen again.

Any thoughts?

[witeshark]

How about the voltage regulator?

[sPoNgE-SA]

Originally Posted by witeshark

How about the voltage regulator?

Is this not part of the Alternator? The voltage is fine now but the battery light still comes on complete loss of power for a second.

[witeshark]

Yeah the regulator is intregral on many. I'm thinking a weak or loose connection somewhere.

[sPoNgE-SA]

I will have to take it back and they will need to have it checked. They replaced the Alternator with a refurbished one. With the same problem still happening would replacing it not of fixed it. Then it's probably something else which isn't part of the Alternator. Could the overcharging not of damaged to battery?

[witeshark]

Overcharging may have caused an issue.

[sPoNgE-SA]

Hi Whiteshark, my car is at the mechanic for two days now. The damn problem doesn't happen when they test drive the car. I even took them for two long drives and nothing. They have checked everything and nothing. They keep telling me that they can't fix it without knowing the problem or seeing it. I even drove the car with Live Data testing and nothing. No error codes. This is very fustrating. Should I get a loan battery and test that ? Any advice please.

[witeshark]

Wow, I guess that's worth a try.

[sPoNgE-SA]

Any idea what amps should be when the Alternator is charging or when there's load on the battery?

[sPoNgE-SA]

ok, so far so good. Car was fine today but too ealry to say.

What was done.
1. Replaced Alternator
**** problem still exists****
2. Replaced Igintion
**** problem still exists****
3. Replaced Alternator and Crank Shaft Sensor, assuming the Alternator was faulty

Car drove 1 day so far with no problems.

Will keep updated.

[sPoNgE-SA]

Youtube video of problem. Recorded a few days ago.

YouTube - VIDEO0004.mp4

YouTube - VIDEO0004.mp4

[witeshark]

Maybe the gage cluster needs a look. It looks like the oil pressure gage fluctuates a lot.

[sPoNgE-SA]

Hey Witeshark, that's the fuel consumpition gauge. Don't think it's a oil pressure gauge.

[witeshark]

Okay, kinda hard to see... Good luck sorting it!

[sPoNgE-SA]

no probs, sorry about that crap video. Was taken with my mobile phone.