Hi - New kid on the block here hoping to get a answer to why my car (2005 Honda Accord LX w/50,000 miles) is making a buzzing or whrrrring noise when the engine is cold and I put it in reverse. It stops temporarily if I brake to a complete stop but it re-starts once I continue in reverse. And when I shift into drive, the noise goes away. This behavior doesn't seem to happen when the engine is warm. I can't tell exactly where the buzzing is coming from. This has been happening for about the last 3 weeks. Hoping for some web-side assistance.

SQLServant
2005 Honda Accord LX
~50,000 miles

 

You could be hearing the straight cut reverse gears whining. Auto or manual transmission?

All forward gears are helical cut and make virtually no sound when they mesh, the reverse gears are straight cut (the first picture of a gear that comes to mind) and it makes a whining/whirring/buzzing sound when they're meshed.

 

It's automatic transmission. To my ears and eyes (when I see bystanders' heads turn in my direction), the buzzing/whining sounds too loud for normal automobile operation.

SQLServant
2005 Honda Accord LX
~50,000 miles

 

Have someone stand nearby to pinpoint the location of the sound. Is it possibly the brakes?

 

Hi -- Had my wife stand next to the car while I backed out. She said it's definitely coming from the back of the car. Ideas?

SQLServant
2005 Honda Accord LX
~50,000 miles

 

That pretty much rules out the tranny...

Rattling exhaust heatshield?
(Probably not 'cause that should keep making noise when the car stops.)

Rear brakes?
LX V-6 has rear disks & the inboard pads have a tab that makes noise when they wear out.
LX 4-cyl has drum brakes so they don't have that tab, but it's still something to check out?

 

The rear brakes could be the culprit. I know that when I'm in reverse and I press the brakes, the buzzing or whining sounds squelched. So if it isn't the rear brakes, it's something very close to them. Thanks.

SQLServant
2005 Honda Accord LX
~50,000 miles

 

Got a V-6 (rear disk brakes)? Or a 4-cyl (rear drums)?

 

Hi -- Sorry for the late response. It's a V-6.

SQLServant
2005 Honda Accord LX
~50,000 miles

 

Check whether the inboard pads are getting thin. There's metal tabs that are supposed to rub the rotors & make a screetching sound. When they first start to touch the rotor, the sound can be much different.