Last night drove the car to dinner everything was fine. Left dinner car started just fine then I get the active steering and dynamic drive error. Drove home parked in driveway overnight. This morning car is dead.. test the battery and its at 6.4 volts ouch. Pull the battery out give it a charge its dated Jun 08 take it to pepboys they do a test and it checked out 857cca battery spec is 850. Bring it home put back in car starts test the charging system jumps around from 13.8-13.9. Just took a drive and it seems like the car is chugging when at a constant speed ie 35 mph in 3rd gear. Pulled up to a stop light and my rpms are staying at or close to 1000. So im kinda confused anyone have any problems like this?

 

battery could have a bad cell in it. maybe when you reinserted the battery, the car needs to be driven a bit to recalibrate??

 

I'd say it's the battery or alternator. Btw, if the battery has ever reached zero charge, irreversible damage is caused to it and nothing will save it.

 

Have your alternator replaced. From the sound of it, it is what the problem is

 

Sounds like the alternator to me also. Get it replaced before your alternator dies completely and the car draws its electrical power needs from the battery which in turn will die also. Happenend to me about a year ago.

 

Don't know why it could be the alternator when you have 13.8-13.9 volts at the battery when the car is running. With that kind of voltage it is obvious that the alternator is putting out. Since you had the battery out of the car I would think that the car needs to be driven for a short period of time so that it figures out what it is doing again. My biggest ? would be why the battery was at 6.4 volts, either something stayed on overnight and dragged the battery down or the battery is bad (regardless of what Pepboys said..like they have a clue anyway).

 

This sounds like the problem I once had with my 540i E39 which I still hold on dearly. Check the terminal cable, are they securely tightened up?