There is a buzzing noise from the engine compartment even with the engine OFF. The noise increases and decreases in intensity. Whatever it was, caused the battery to die. May have started after singoe occurrance of heavy breaking.

 

did you by chance figure out what this was? I am having the same exact problem, any help would be great.

 

I finally got the chance to change out the battery and that seems to fix the problem. The auto parts place checked the battery and it had a dead short. When the battery died, the noise stopped. With the new battery, everything (knock on wood) is back to running ok. All anyone I talk to can say it that with the shorted battery, it was causing the computer to act up. As far as I know, the computer is in the area of the instrument panel and is always alive even with the car off just to keep track of stuff. I would have your battery checked. Hope I have been of some assistance. Please let me know what happened.

 

Hi Winston03.
Did the Buzz ever stop and start on its own, or was that the only time, when it drained your battery?
I think I had the same buzzing noise last saturday. I noticed it when I got out of the car with the keys in my hand and the ignition off. I waited for it to go away but it didn't. I started the car and turned it off again, but it kept buzzing. An hour later, after reading your post, I unhooked the Negative battery cable and it stopped. Monday morning I made an appointment at The M Shop in Eagle Rock CA. I hooked up the negative cable. The buzzing was there for a few seconds then went away. I fired up the engine and drove about 8 miles to the shop and it still wasn't buzzing. I've driven it another 10 - 15 miles today and still no buzz. Now I'm listening every time I get out of the car.
I'd like to know if it happened more then once?
Thanks.

 

Kellymac,

The buzzing was there when the key was turned off. After a 3-hour meeting the buzzing was still there. The car was started and driven home. The buzzing was still there when the key was turned off. The next morning, the MINI would not start. The battery was completely dead, no light, no attempt to start, nothing. We had the battery checked and it was completely shot. Replacing the battery, so far, fixed the problem. As an add-on, the day the buzzing started, the driver had to make a panic stop. A person familiar with batteries said that sometimes after a panic stop or any other sudden shaking of the battery, all the build up on the individual plates comes loose and shorts out the battery. When you disconnected the negative (ground) lead, you may have reset everything. You can ask a battery expert about that.

Hope this helped.

 

Thanks Winston03.
I've driven about 65 miles since yesterday with no buzzing noise or battery drain. The car started fine this morning. I had emailed the shop before I took it in and they wrote back that it might be coming from the power steering pump fan. I wrote them back asking if there would be any other symptoms for that.
Since the buzzing stopped I keep wondering if it is working correctly or is it dead? I dont know how to tell. I do know if the power steering pump goes bad its big buck to fix.

 

I've been researching said humming noise for a while and I stumbled on this board as a result. As of right now, I have a brand new battery on my Mazda 3 2006 and there's a direct correlation between the humming/buzzing and the battery getting drained. After driving, shutting the engine off, putting the keys in my pocket, and lifting the hood, I can hear a buzz/hum. If I unplug the negative terminal, there's a brief "hiss" and the buzzing stops. No drain takes place as long as I keep the battery unplugged. I've taken it to an actual Mazda dealership and they couldn't even figure it out, but they did mention that my fuel injection system needs cleaning. Someone else who allegedly knows about cars (not a mechanic) said that it was probably the fuel injectors are somehow still trying to pump fuel into the engine even after it has been shutoff. I don't know much about cars other than changing tires, sparkplugs, and doing oil changes. Any help would be greatly appreciated!

 

it might be the aux water pump. it usually stay on for a little bit to cool off the engine. so, there might be a sensor that tells this pump to stop that isnt working.!

 

So trying to help a useless individual get their car fixed so they can move out of my home...

2nd new battery is dead, was going to workin thermostat and such & so we can get it to the shop that did the alternator before either new battery (he says sounds like a bad Alternator thta is under warrenty & he is going to make it right) So I hooked the battery up to charge. Normally after 4-5 hrs, a battery would be at least halfway charged.

But the parking light were left on, battery was so dead they didn't (dimly) come on until it reached 17%charge. I turned the lights on to auto & the parking lights were still on. and there was this buzzing coming from the dash/louder under the steering column. Put the key in & turn to on, buzzing got super loud and parking assit button's light came on then went off.

Take key out buzz gets quieter, unhook charger & parking lights/buzz stops.



I unhooked the corroded (cleaned bit need replaced) ends of the battery & hook charger up to disconnected battery. Charging speed is back to normal.

Took video to show the mechanic tomorrow. I am thinking the voltage regulator is the issue & wonder if it could make both the barttery and alternator go bad.

Here's hoping to get it fixed long enough to get him out of my house. Bum couldn't even help work on his own vehicle.

 

See my attached video — Is this the sound you are all speaking of?

I drove 45 minutes ~55 MPH most of the way. Outdoor temperature is about 43 Farenheight so I didn't have on the heat nor air conditioning.

I had shut the vehicle off for about 30 minutes and then came out into garage & while standing about 18’ feet away I could clearly hear this short intermittent electric-motor-like-buzz that I would describe as a deep-sounding bird-of-prey. It was quiet enough at that distance that I could not tell if it was the vehicle or if it was a sound from outside the garage.
At that point, it was repeating every 20 seconds at that point but as I tried to hunt down the sound the frequency over about 10 minutes time, the frequency of recurrence shortened to about 6 seconds between buzzes.
The buzz/screech sound itself was consistent in tone and its duration of about 1 second.

I then started the car, ran it for about 5 seconds, then shut it off again and the sound did not return.

The sound seems to be coming from the passenger side near the front of the engine. It seemed loudest when I was on the ground listening from the underside of the passenger front bumper.

My uneducated guess is that it’s probably a pump or solenoid valve of to relieve pressure or to prime/charge up something.
Could it be for fuel evaporator? Or for engine coolant?