Any ideas ... troubleshooting a clickety clunk

[clueless1]

The frequency increases with vehicle speed (not RPMs). So if 'no noise when depressing clutch' means trans not engine, then 'varies with speed not rpm' means ? i'm wondering about axle to cv joint?

Sounds like something is knocking, but its difficult for me to describe well.

Its a 2001S with a 6 speed manual

[insite]

you mentioned that it stops when you're out of gear or when the clutch is pressed. what about when you vary load? does it go away when you get on the gas? when you let off? how about in corners; does it go away? get worse?

[clueless1]

Nope, does not seem to change with gas (nor brake), nor around corners (although it was harder for me to assess the latter on my short drive to work today). My newest description for the sound today is like a cracking sound.

[insite]

what's the approximate frequency if you had to guess? 60 beats / minute? 120? trying to figure out if it's like a buzzzzzz or like a crack crack crack

also, are you CERTAIN it's coming from the right side, or is it very hard to tell which side it's coming from?

[clueless1]

I stuck my phone out the drivers side between red lights and recorded 30 seconds, rather than continue to describe it badly. I think the car was generally between 2000 and 3500 RPM in this 30 sec stretch. The sound stops abruptly at the end because I engaged the clutch and coast the last little bit.

Its definitely a crack, crack, crack.

I haven't had assistance from anyone, and its only audible when driving, so all I can tell you is from the perspective of the drivers seat. To me it sounds like right rear, but it could be coming from absolutely anywhere.

http://audioboo.fm/boos/179980-boxster-2001s-noise

As you will hear, the frequency varies with the speed of the vehicle. I do think there are times when I have been able to rev the car out of the noise (it seems a bit less distinct above 3000 RPMs, and its felt at times that I rev out of it around 4-5000 RPM. I felt like when the car lurched the sound would start up again. That could all be in my head though. I wondered if there were a few times I didn't rev out of it -- hard to tell because the engine sound drowns out the click around that level, and it would 'return' around the same time it would have become audible regardless)

Thanks for all advice offered. Its raining now, but I need to figure out what to look for / how to look at it and get under her this weekend.

[insite]

i can't be sure without driving the car, but my gut tells me that the ring gear in your differential is damaged. a seasoned porsche mechanic should be able to drive it a hundred feet and tell you if that's the cause of the noise.

(i hope i am wrong!)

have you ever had the transmission fluid replaced? if it was filled incorrectly, this can happen.

[Pat]

lol diagnosis via Internet.

[clueless1]

Originally Posted by insite

i can't be sure without driving the car, but my gut tells me that the ring gear in your differential is damaged. a seasoned porsche mechanic should be able to drive it a hundred feet and tell you if that's the cause of the noise.

(i hope i am wrong!)

have you ever had the transmission fluid replaced? if it was filled incorrectly, this can happen.

no, but i just bought the car a month ago.

what makes you think it is the ring gear in the differential?

other than inspect cv joints (is there a way that depressing the clutch could remove cvj noise????), is there anything else i can / should do to inspect for the obvious?

what would a porsche vet be looking for when driving the car that would be indicative?