Any ideas ... troubleshooting a clickety clunk

[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.

[eightsandaces]

Originally Posted by Pat

lol diagnosis via Internet.

lol all you want, my engine noise was properly diagnosed on this blog.

[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?

[insite]

Originally Posted by clueless1

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?

the CV axles would generally make noise all the time, and the noise would have a higher frequency & a different sound. pressing the clutch would not affect CV noise.

other driveline issues could be the flywheel, clutch, throwout bearing, etc, but all of these would vary with RPM, not with vehicle speed.

the pinion gear & ring gear in the diff would both vary frequency w/ vehicle speed. when the pinion is damaged, the sound frequency is high, more like a freewheeling 10-speed bike. when the ring gear is damaged, the sound is very similar to what you recorded. also, relieving load from the gears by pressing the clutch or hitting neutral CAN make the sound go away. it will, however, get worse over time, and will eventually happen whenever the car is in motion.

i would still have a seasoned porsche tech drive the car & give you his impressions; i could certainly be wrong. it's hard to diagnose car noises over the internet.

FYI, a ring gear isn't all that expensive, but it can be tricky to install properly. the real issue is (if this is the transmission) that the pinion could be damaged, too. this is DEEP in the tranny & hard to replace. if this is indeed your problem, the easiest solution is to source a tranny from a wrecked car & install something else.

another thing i recommend? take someone for a ride and ask them which side the noise is on. i bet they say the left. if the driver hears it left & the passenger hears it right, it's in the center......transmission.

let us know what you find out.