Odd buzzing noise from rear of car

[WolfeMacleod]

This started a little while ago, and happens randomly. Not very often, and it doesn't matter whether I'm braking, accelerating, or idling.

Coming from the rear, it sounds like it's on the passenger side of the car, somewhere under the rear deck. At first, I thought I'd blown a speaker...but no.

It sounds much like a cell phone on ultra powerful vibrate under the rear deck or something. Gets slightly higher in pitch, and then dies. Only last for a few seconds. It's always the same. Engine speed does not matter.

What could cause this intermittent, random noise from that area of the car?

[DRACO A5OG]

AAV (Ambient Air Valve), engine compartment passanger side under lid arm next to the oil filer neck.

It will look like a wide bell shaped plastic part with 3 hoses coming out of it (one out of the top another toward the front of the engine and then other to the oil filler neck) held by a brass bracket.

If it has been updated, it will be a metal flying saucer part about 3" in diameter and inch tall, two hoses toward the front and one to the oil filler neck.

I bet it only makes that noise when your baby is cold or cold mornings, huh?

Hope this helps

[Buckterrier]

engine bay buzzing noise
And I'll bet it sounds like a kazoo and it only happens when it's cold.

[WolfeMacleod]

Originally Posted by Buckterrier

engine bay buzzing noise
And I'll bet it sounds like a kazoo and it only happens when it's cold.

Well, sort of kazoo sounding I suppose. But it happens when it's warm and been driven a while, too.

Going to take the car out today to pick up oil..we'll see how many times it happens.

[richde]

Originally Posted by WolfeMacleod

Well, sort of kazoo sounding I suppose. But it happens when it's warm and been driven a while, too.

Going to take the car out today to pick up oil..we'll see how many times it happens.

Cold outside, not cold engine

[madmmac]

If you have auto-heat it could also be the flappers adjusting themselves. I hear mine every so often, but they are not very loud.

[WolfeMacleod]

Originally Posted by madmmac

If you have auto-heat it could also be the flappers adjusting themselves. I hear mine every so often, but they are not very loud.

Nope, no auto heat that I know of...happens whether the heat is on or not, too...

I'm thinking it's got to be the subject in the post linked above.

[Jgordon]

it's a stretch, but I just got my car out of hibernation, and the heater fan was causing a racket. More of a squeal than a buzz, but it's worth a thought.

[450knotOffice]

Wow. I always wondered what that noise was. I haven't heard it in a while, but you definitely described it perfectly. Thanks for the answer, Draco and Mark.

[WolfeMacleod]

Originally Posted by 450knotOffice

Wow. I always wondered what that noise was. I haven't heard it in a while, but you definitely described it perfectly. Thanks for the answer, Draco and Mark.

Well, I would hope I could describe it well. I make my living dealing with sound, and people describe various aspects of sound and tone to me all day, every day.

[wastintime]

This is making me rethink an odd noise I've had on my 964 latley... similiar, but higher pitched... hmmm, something to think about anyway, and I bet I do have auto-heat...

[john walker's workshop]

probaly that plastic valve just in front of the oil filler cap.