[bmwmiami335]

2007, 335i sedan, was driving on the highway the other day, and pretty much had a full system shut-down on my car. all the lights and warnings came on, and I had major power loss. I tried to pull off the highway, and then my upper coolant hose popped off and started spraying everywhere. ( i guess the water pump shutoff, and built up pressure)

had the car towed to my local mechanic, he told me the alternator was fried. he changed that and the battery. then he told me that my alternator was pumping out 20v and had to figure out how to fix that (I realized later he had to register the new battery, but didnt know this at the time). he claims he left battery disconnect overnight, and now it is fine

but since I got the car back, I noticed a few things.

• a little sluggish
• oil level sensor shows inactive
• and there was an intermittent buzzing from under the hood, with the engine off, when I unlock my doors, or after shutting off the car.

I realized the buzzing was the water pump.
I also checked the codes from my JB4 and the only code I got was 2E7C (BSd cable)
I checked the battery and sure enough, the BSd cable is not connected. looks like the mechanic cracked the plastic connector when he replace battery and just left it. (there is also another 2-wire harness that I cant figure out where it goes, but the posts on here are saying thats normal...??)

I cut the wires and spliced together for now. was really hoping that would fix the problem, but oil level still shows inactive.

disconnected the battery overnight, and I have no idea what else to check from here.

are all these related? from some of the articles im reading, it seems the water pump and the oil level sensor are inter-related. other articles (I think for previous years) seem to say the alternator somehow connects the oil level, and if you install a cheap alternator, oil level will show inactive???

if they are all interrelated which one is bad?
the oil level sensor?
the water pump?
the BSD cable?

as always, I am very grateful for the e90post community! you guys are the best

[robthewrench]

For the BSD and battery, the very small gauge 2 wire connector is not connected to anything. This is only used when the car is shipped from the factory.

You should go back to that mechanic and show him the cracked connector and BSD error message. He should replace the BSD cable for free since he broke it. Also ask him about the waterpump noise and the oil level sensor. He should at least re-look at these at no charge.

If he gives you grief, remind him that he's not put your car back to normal condition and continue to press for him to get it right. Think about finding a different mechanic. If this one disagrees with you about the BSD you can't trust him.

[BashShah]

Originally Posted by robthewrench

For the BSD and battery, the very small gauge 2 wire connector is not connected to anything. This is only used when the car is shipped from the factory.

You should go back to that mechanic and show him the cracked connector and BSD error message. He should replace the BSD cable for free since he broke it. Also ask him about the waterpump noise and the oil level sensor. He should at least re-look at these at no charge.

If he gives you grief, remind him that he's not put your car back to normal condition and continue to press for him to get it right. Think about finding a different mechanic. If this one disagrees with you about the BSD you can't trust him.

10+

If you know he doesn't know what he is doing, and if you do go back to this mechanic, then you risk him not doing it right again.

Bash Shah
Sutton Premier Realty