So I've got a 2000 CX hatch. I've just noticed the past couple of nights while I was out in the garage doing some work (while the car is completely turned off) a high pitched buzzing sound coming from the direction of my car. It lasts for about 5 seconds, then stops. It seems like it does this every 5-10 minutes. Earlier tonight it only did it twice and then stopped for a while. It may just be sitting in the garage buzzing away right now.

This was even 30 minutes to an hour or more after I had driven the car though. It doesn't last long enough for me to be able to get to the car and find where it's coming from. It's loud enough to hear outside the car 30 or 40 feet away. I'm stumped. Any clues what the hell it could be?

a little more about the car if it helps... has a remote starter/power door locks installed, walbro fuel pump (but this noise isnt the same tone as the fuel pump. it's higher pitched), turbo car so its got all the peripherals for that, wired for a stereo but no amp hooked up - just head unit and 4 speakers. power/ground wires still hooked up but fuse is removed.

 

you sure its nothing from your alarm. theres not really much that has constant power that would make a constant noise thats high pitched. also could it be a socket in your garage? or can you hear it when the car is not in the garage

 

Well my garage is pretty quiet. I guess that's why I noticed it there. I haven't been parked anywhere else quiet enough to hear it. I turned off all the lights and everything and it still did it. My first thoughts were the deep freeze, refrigerator, anything else but its definitely coming from the car. I actually thought it was a cell phone vibrating loudly somewhere on or in the car. It wasn't.

I remember on my '07 mazda cx-7, it has a fuel system check it performs about 15 minutes after the car is turned off to test for leaks or excess pressure. Think it's something similar? Being a 2000 cx i wasnt sure if it had a feature like that.

I'm gonna try removing the gas cap for about 30 seconds next time it does it and we'll see if that fixes it.

 

I have the same thing going on on my 2001 Integra GSR. Turn off the car, and buzzing noise every 5 minutes. Been doing this for years, I just ignored it.

 

Brakes cooling down, leave the parking brake off and listen again.

 

checking the evap system sounds like good idea is the MIL on?