Hi guys, I was not able to find a video or sound clip online that resembles what I am hearing from my S, so I stuck a gopro and phone on torch mode under my car to hopefully shed some light on the situation.

https://vimeo.com/112130587

Video description: I did 3 drive (roll in neutral) bys in the video, and you can hear the squeaks in the first and 3rd drive by. The squeaks sound like a bunch of mice or a bad tape in a tape recorder, and is very subtle, may have to turn your volume up on this one after the first run through the video.

The squeaks happen between 6-10 seconds on the first roll by, the second roll by is "normal", and the third roll by has squeaks that you can hear at 27 seconds and picks up at 30-33 seconds.

Occurrence: The squeaks only occur at idle after driving around for 15 minutes and it doesn't matter if the clutch is engaged. I can also hear it with the windows down as I am decelerating in neutral (down from 20mph when wind isn't an issue).

The squeaks go away the moment I apply load (slowly engage the clutch, no throttle), or when I'm in neutral and apply throttle. The squeaks do not sound like they are coming from the engine bay at all, which was why I spent a few hours searching the internet for any transmission/clutch related squeak and couldn't find anything relevant.

Any ideas?

Thanks in advance

 

To me it sounds like its coming from the cat or around there.

 

Clarify if the noise occurs while car is stationary, or only when its rolling.

The description sounds like a serpintine belt driven accessory with a bad bearing. I'm at work now and can't play the videos.

 

It can be heard both rolling and stationary. I was doing roll bys to try and get a sense of where the noise is coming frombthe car. The thing about it being stationary, though, is that I can't just jack up the car and expect to reproduce the sound because the sound goes away if I'm sitting for a few minutes. Maybe next I'll try leaving the engine on for 15 minutes to see if I can reproduce and narrow down the root cause - it should get the motor and exhaust warm but transmission stays relatively idle

 

Probably an exhaust leak somewhere.

 

Normally I'd suggest taking off serpentine belt and starting motor, to see if noise goes away. Then you'd know it was one of the driven pullys. But since its intermittent, you wouldn't know right away if there is no noise, and you obviously don't want to run like this for any length of time (overheat engine).

But I'd still suggest this method. If you do still hear the noise, you ruled out all the driven pullys. While belt is off you can feel each pully by hand. Spin it to see if there is noise, see if there is too much play, etc.

 

A few weeks ago, I replaced the tensioner pulley bearing and there was no sound improvement but did help a tiny bit of the wobble. Idler pulley was okay. I can't recall all of the details when I looked but it didn't -seem- like the sound was coming from the water pump or alternator; will check again the next time I jack the car up this weekend. I'm 99% confident the noise is coming from under the car behind the front wheels and not the engine bay. When coming to a stop in my street, I quickly jumped out and opened the hood when the sound was occuring, and wasn't audible in the engine bay.

I'd be surprised if it was exhaust or catalytic converter related but will check anyway. I checked throwout bearing noises online but it doesn't resemble my squeak - I'm not ruling out the cause though, maybe the squeak is what leads to the traditional throwout bearing noise?