To clarify...it buzze immediatly after the door is opened and it lasts about a minute.

Seems to come from under the hood and it lasts about a minute...I notice it mostly when I'm in my garage...and I have opened the drivers door for one reason or another (but not started the car). I'm confident this is not a problem...I'm sure the car is doing exactly what it needs (and is supposed) to do...But what is it doing??

 

Many have speculated what it is but I've never seen any concrete information on the exact source of the noise. It clearly is normal. You'll find sometimes the car will buzz just sitting there -- without you even touching it.

I've heard people say the noise is the SMG hydraulics energizing, the active roll system energizing, etc. It could be some sort of pre-ignition fuel pump, hell, it could be anything as far as I know.

I'd love to hear someone truly identify what it is. Maybe some of our members with "inside" information can shed some additional light on this?

 

Well I'll rule one of those options out because I don't have SMG...so now I guess we're down to only 1000 things it could be. As you mentioned it would be nice if "someone" could come up with an answer...I guess we'll wait and see.

Chris

 

I'll answer another one - I have a 5-spd, and no sport package. I think it has something to do with the electronics and battery, but that's pure speculation. I am curious as to why it does that though!

 

We need a Francois answer here!

 

My 2000 Acura RL does the same thing - a "mysterious" buzzing sound that is intermintent but has persisted as long as I've owned the car. I thought it was just a Japanese "thing" since my 2002 Porsche 911 Targa doesn't make any similar sound. I guess when I get my 545i I will feel right at home with the sound.

 

ch, I think this was brought up in a previous topic (you may want to check it out) but I will give my best explanation since it happens to my car also. It has to do with the car waking up from sleepmode. If you notice, when you turn off the ignition, there is an orange light on the shifter console that stays lit for approximately 20 minutes, then it goes out. Supposedly, when the light goes out the car is in sleep mode. Thereafter, any attempt to open the car doors or the trunk wakes her up, thus the source of the buzzing sound ( I guess its doing whatever calibrations or computer readings it does). I wouldnt worry about it its seems to be normal.

 

By the way if anyone else concurs with my statement above please say so or if they think the source of the buzz is from something else. Thanks

 

I'm not disagreeing with you by any means.

I think we're all in agreement that the car is waking up or "initializing" something. The lingering question is what, exactly, is waking up?

Also, I will add that the car makes the noise sometimes just by itself before going to sleep. I've also heard it make the noise when unlocking the car while it is still "awake" so I don't think it's limited to waking up from sleep mode.

Somebody out there will eventually tell us something concrete I'm sure!

 

I thought it took an hour for that orange light to go out. ??? I believe Rudy even said it did. I know my tech told me that.