Instrument cluster display buzzing noise

A couple of times (when it was quiet enough), I thought I heard something like static noise after turning the car off.

I had assumed it was coming from the speaker on the A-pillar (I have the Harmon-Kardon stereo), but didn't have time to really investigate. The next time I get the opportunity, I'll see if I can do a better job locating the source.

 

We're you running the AC beforehand? When the car is turned off, it will continue to run the fan on low for a while to dry out the moisture on the evaporator.

 

Great question. I don't recall if the AC was running for that trip, but I can say that I have noticed the fan continuing to run after recent trips in warmer weather and it's clearly a different sound coming from a different location.

The sound I'm talking about is similar to an amplified speaker with the volume turned up but no signal going into it. I took note of it because I knew I muted the radio before pulling into the garage, so the speakers should have been totally silent.

 

I'll pay closer attention as I'm about to be putting 300+ miles in the next few days. So some quality time in the car. With South Carolina heat and humidity, my AC has been on 'auto' mode for probably 99% of the miles I've driven! So I'm used to hearing that fan running, and I agree it does not sound like static or buzzing.

 

To my ear, it's the kind of sound that's easily drowned out by driving and surrounding traffic/environmental sounds. I have only heard it inside my garage, with the garage door closed and the car off.

 

I hear this sound as well; I can't tell where it is coming from, but my assumption originally was that it was from outside the car, but it's hard for me to place.

My best description is it sounds like a very high pitched whine that old TVs from the 70's and 80's used to make when they are warming up. I hear it as soon as I turn on the car with no radio on. I also note that it blends into the background when the car gets moving but when I'm sitting still it does seem more obvious and annoying.

I haven't figure out when it turns on or off (or if it ever turns off) - the only time I'm sitting still and don't notice it is when I'm charging my car at a DC fast charger; but that's hard to tell because they all seem to make a droning noise when they start the charging cycle.

 

It could be the sound of the heat pump/compressor that's pretty loud and will run to condition the battery and when AC is on. Might want to repeat your test and step outside the car to hear what's going on.

 

Unfortunately I see a pic and no sound file. All modern Minis I've driven have had what you are describing. Sounded like a normal slow shut down to me.

 

Thanks for the link. That's actually not what I hear with mine or my old Mini. It would've sounded like something was amplified but more like a hum than what you have. I am sorry I am of no help

 

@polyphonic and @quietlyspinach, do you have (and use) the HUD?

I just took a quick trip with the AC off and heard the sound when I got home (again, only in the garage with all doors & windows closed). After moving my head around the area, it sounds like it may be coming from where the HUD is - I speculate there's a cooling fan for the super bright backlight necessary for that display to be seen in sunlight.

 

That's good information and experimentation, @polyphonic - thank you for sharing.

I just got in my SE and activated "radio-ready" state to wake up the instrument cluster. I didn't hear that sound. I could hear a cooling fan inside the Central Information Display, which continued after I turned the car off.

I'll try some other tests and see what I can learn.

 

When you hear the noise, feel the back of the instrument cluster. I heard something coming from it today (if I put my ear close) and it was very hot on the back side so most likely a fan.

The head unit is behind the touchscreen and also has a decent size cooling fan.

 

Yeah, my quick test likely didn't leave the instrument cluster display on long enough to require a cooling fan--just long enough to confirm it wasn't the display screen making the sound.

I'll try another test later where I leave the instrument cluster on longer but ensure the HUD is deactivated.

 

Confirmed. Several minutes after returning home from a trip (after all cooling fans turned off), I went back out to the car and could hear the sound with the instrument cluster display on and the HUD still deactivated. Turning on the car, I could hear the HUD's cooling fan adding to the noise, but with a different/slightly lower frequency.

I'm fairly certain that the "amplified speaker with the volume turned up" sound is the cooling fan for the instrument cluster display.

 

Good sleuthing on this thread!

 

Dammit! I didn't hear this noise until I read this thread!