Doublebase

I have this weird electric motor noise that comes from the rear a few seconds after I shut my car off (I don't have the leveling air suspension). I also hear it in the engine compartment on occasion when the engine is shut off (I've heard it hours after the car is off). It lasts for a couple of seconds and it's gone. I do have the car set on auto ebrake. That's the only thing I can think of causing the noise...like the cable loses tension and the motor tightens it, but I don't really know. Anyone else experience this?

Johnhw2

I am too new an owner, two days, to know but wonder if the model might make a difference to post.

Devh

Just a guess, it could be the vapor purge motor that releases pressure into the emission charcoal canister. Many modern cars especially luxury have some regulatory features when the car is in the off position. I wouldn't worry about it unless your battery gets prematurely drained.

Doublebase

No problems with the battery...I never considered the evap system.

Devh

My previous BMW was worse. It would make all kinds of electric motor noises hours and days after the car was turned off. I read somewhere that it might be Vanos system activating the motor to keep checking it's position and calibrating constantly and if so it's a poor design on BMWs part.
The evap system would constantly moan as well.

peteybabes

I've heard the same noise Doublebase, i had just assumed it was the Air Suspension making noise...

Doublebase

That's got to be tough on a battery in cold weather.

Doublebase

Glad I'm not the only one.

Devh

It probably is but I remember reading that cars of this sort usually have batteries that have lots of reserve and are generally deep cycle. The Panasonic batteries that Toyota uses are first rate.
If I told you how complex the BMW charging system is it will drive you mad. Complex electronics is the death of the modern automobile.

Doublebase

I've never tried Panasonic batteries, but I agree, electronics are going a little too far on cars today. You can't even replace simple things without getting it programmed from the dealer,mot me that's not right. If I diagnose something, remove it, install it...I'll still get porked by the dealer. And then the dealer will tell me they have to charge me an hour to diagnose it anyway, before they program it.

rfam

hey doublebase, I too have the same weird noise on my 2012 periodically. I cannot seem to pinpoint the cause-just so happens every so often after it has sat for a day or so. Sometimes when I open a door or pop the hood..I hear it. No issues with my battery-still on the original. All else works. Just spent some time with the head diagnostic and shop foreman at a huge dealership asking them some questions about the car and its long term reliability but failed to ask about the noise-my mistake.

Doublebase

What did they say about the long term reliability? As far as the noise goes, devh posted above that it could be the evap system running a test. That makes the most sense to me, but it was just a guess.

Devh

I get that too when I open a door sometimes or it doesn't happen at all. Unless the battery is drained because of it or you get a check engine light I wouldn't worry about it.
Worst case, If something is broken it will let you know and there is no point in worrying because it will have to be replaced anyway.
The shop forman can offer you some insight in to the reliability but you have to keep in mind he is not an engineer to make a determination of a cars long term reliability.

rfam

I had an appt. with the head diagnostics ((over 20 years with Lexus) fellow to ride with me on a cold morning so he could listen to the diesel-like noise. Bottom line on that is he said the engine sounded normal and heard nothing out of the ordinary. I guess I'm more sensitive to the knocking sound it emits before it reaches operating temp. coming out of a 2000 ls that is whisper quiet all the time. Anyway, I asked him what was the most miles he had seen on this model-replied 2007 was in the other day with 312,000 miles-a salesman who obviously lived on the road! Concerning transmission fluid changes-say he would not touch it-they have never seen any trouble from NOT changing the fluid. Asked why 2012 can't go to 10,000 oci like the 2013--had no answer-suggested to go to 7500 miles on the syn. 0w-20. In the end, he had nothing to say but positive things about the car and its realiability. Also, had not seen any problems with the electronics which is great to hear as I plan on keeping this 10-12 years or 200,000 miles. He did note several of the issues that have been well noted in this forum have been corrected.

hfahmy

I think what you hear when you open the door is the brake actuator pressuring the brake fluid into the system. if you close the door and leave it for a little while you will hear the fluid depressurized. I think this is normal.