BMW Repair: 02 - 330i, car radar detector, altenator

Question

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Followup To

Question -
The other morning my car dint star i check around and the battery had a bad cell a was getting 10v, got a new one from the dealer and work fine for a few days, then dead again, jump stared and it crank, i run a starter,altenator and battery test and everything read out working properly. I read about a starter recall on E46, M54 and M56 engines which were produce from 3/12/02 - 10/12/02, but my car was made 10/01.
Any Advice?  Thanks for your time.

Answer -
Joe, your starter should be fine. I can count the number of starters I have replaced at BMW on one hand. Mainly due to noises. You need to check to see if you have an excessive current draw when the the car is asleep. Make sure you don't leave any aftermarket accessories plugged into the car (radar detector,cell phone on charger). This will keep the car awake and prevent modules from shutting off completely. Leave car and make sure the trans. gear selector LED goes out after about 16 minutes. If it does then the car is going to sleep. You still may have a current draw that will drain the battery. The car can draw a maximum of 40 milliamps on your model after the car goes to sleep. Normal is 20mA, but 40mA is max! If you are a do it yourselfer and have a good Multimeter (one that can read upto 10Amps) then reply to this post and I will give you further instruction if you are interested. If not take car to dealer and tell them to check for a Closed Circuit Current Draw and ask them what the reading is when the car is asleep.
-Evan

Reply -
Thank`s for your time and quick respond, now the mention there is a small noise sometimes around alternator or some pulley, don`t have
aftermarket accessories, gear selector LED seams fine, mechanical inclined, have multimeter, I'm interested on further instructions. Thanks Again,
Joe

Answer
Joe, What is the battery voltage after the car sits over night. If voltage is low then you need to check the current draw. To do so open the passenger door, glove box, and trunk. Manually close the passenger latch completely on the door. Do the same with the rear trunk. Switch your meter to 10A range. You need to be able to measure milliamps (0.000) Make yourself a 2ft. or so jumper wire with alligator clips on either end. Wait until the car goes to sleep (LED goes out on the gear selector). Connect the jumper wire to the negative battery post- connect the other end to a good metal chassis ground (check with ohm meter). You just made a parallel battery ground. Remove the negative battery cable at the car ground end (13mm nut). All power should now flow through your jumper ground. Now connect your Amp meter from the negative battery post to the chassis ground. 1/2 the current will flow through the meter. Unclip the alligator jumper and all the current now flows through the meter. Read your meter and tell me what you find. 0.020A is what you would like to see. 0.040A is the Max permissible. It is very important that at no time do you completely loose connection between the car and the battery. This will reset all the modules and you want to catch the problem in the act. If you have an excessive draw over 40mA. Start pulling fuses from the glove compartment fuse carrier one by one. Lay the fuses down in an organised manner and recheck the meter after each pull and wait a minute for the reading to stablize. Don't put the fuse back until you are totally done because replacing the fuse make wake up modules on that circuit. Let me know what you find.
-Evan