"Help" Charging system Malfunction with smoke
 

Hello everyone,

Car is 07 550i.

I am having an issue where the car starts to smoke and I get a red battery signal for charging system malfunction. I pulled the code (2E97) for alternator fault, kinda generic. What troubles me is that there is smoke coming from the general area of alternator but I can't tell if its from the alternator itself. It seems like it may be deep behind the alternator. The smoke smells like rubber and other times it smells like oil.

I checked to see if the belt was ok (visually), the alternator also seems to be turning ok. The car drives normally no starting issues, no flickering, all interior and exterior lighting works ok.

Also the alternator was replaced in Nov 2013. Voltage while driving is 12v as measured from the cig lighter.

Car is due for valve cover gaskets. That all the info I can think of.
Any ideas?

You are smelling oil and rubber? Have you checked if oil was getting on the alternator. I would remove it and make sure the connections are not burning.

Taking out the alternator is a big job. I suspect that might be happening but it is very hard to tell. I pulled out the air filter housing but I couldn't really see anything.

Most likely this:

https://www.google.com/search?q=bmw+...ernator+gasket

I thought about that but from research that doesn't normally leak into the alternator, it is a little back from the alternator. Also, I took the car to the dealer a few weeks back, they noted the valve cover gaskets were leaking. After looking at it it appears the valve cover gasket at one point extends to just over the alternator.

I have to replace the alternator now because my battery is not being charged at all. I want to do the valve cover gaskets, timing gasket, etc. along with the alternator and alternator bracket all at once since the engine will be out but dealer quoted me $3000+ and Indy(who is 3 hours away) quoted $2500+. Not really a good time for all this crap.

Do you live in Dayton Ohio. If so there is a Foreign Exchange there who can give a quote. Also there is another place to go Specialty Auto Werks. Most indy shops will let you buy your own parts to save money. The gaskets you can buy from pelican parts (OEM Supplier) for a third of the price as BMW parts and it will be the same part without the BMW box. The alternator below is the same one you will get from the dealer (REMAN). This should save you at least $500.

I live in Cleveland now but goes to Dayton just about every other week, thus the 3 hour drive I was referring to. Foreign exchange was the second quote. I have used them before and they are very good. BMW even use them as a subcontractor for coding. I have been in Cleveland for about a year so not familiar with Indy's in the area.

My alternator was from auto zone and I have warranty on it, already spoke with them they will replace it. I don't think the quotes are terrible, I just didn't want to drop that type of money right now.

Anyone have any idea why the alternator powers the car but doesn't charge the battery?

The alternator voltage regulator may be failing and unable to work with the alternator to produce a sufficient current output to keep the system voltage high enough, given the system load, and thus to charge the battery. Every electrical device in the car (including the battery) basically sees the same system voltage. The ideal battery charging voltage is around 14.3V but if the battery is low on charge (as measured by the IBS) the DME may ask the alternator voltage regulator, or VR, to create a system voltage higher than 14.3V to accelerate battery charging.

Generally if the system voltage drops below 13.5V the DME will signal the VR to increase current output. If the VR is unable to raise the system voltage and it drops to a critically low level, the DME may begin to shutdown systems such as the transmission control, stability control and active steering systems to conserve current which will generate dash warning lights. But the system voltage may also swing up and down, not charging the battery and also not generating system faults.

What system voltage are you measuring between the jump terminal and main ground lug under the hood while the engine is running? Have you measured the system voltage several times during the drive to see if the VR is swinging up and down?

If the alternator is producing 14.2 to 14.7V for a coded AGM battery, or 14.2 to 15.5V for a FLA coded battery then the battery normally should be charging. If not there could be a dead cell (which can happen in a new battery), or there may be damage to the electrical conductors between the alternator and battery (either positive current or ground conductors), which can inhibit charging.

For your MY a possible cause (though not as common as earlier E60 years) for the battery to not charge properly could be the IBS or intelligent battery sensor.

If the battery is thoroughly tested for dead cells and checks good, and the alternator is producing enough current to reach a 14.3V+ system voltage then you can try disconnecting the communication line from the IBS. If the battery still won't charge with the IBS disconnected then I would begin to look at electrical connections.

Appreciate your lengthy and informative post, as always. I have not measured from the jump terminals but I measured from the battery while the car was running and I also had a constant measurement while the car was being driven. The measurement started out at around 12v then constantly got lower and lower over two days of no charging. The charging volt remained constant except for the loss after several starts, no significant variations such as when an alternator is going bad. The alternator was replaced 2 years ago. I knew the alternator was bad then because the voltage would go from 11-17 and the dash would die while driving. The voltage got down to around 11.2 so I had to remove the battery and charge it today.

I also replaced the IBS this morning same results. The battery is only 2.5 years old. I don't believe it is a battery issue. I believe the oil has dripped onto the alternator causing some short circuit. As I mentioned before there is some smell of rubber or oil burning and I do get some smoke.

I was puzzled as to why the car seems unaffected except for the battery not charging.