Hi guys,

so here's the low down. I have this noise that comes and goes intermittently. To me it sounds like a pipe vibrating at a high frequency in a c-clamp that isn't fully tight. Basically it's a metallic screeching.

The following must take place for it to happen:

1. car must be warm, really warm. I have to drive for at least 30mins for it to heat up and have the temp needle at least at dead center.

2. it only makes the sound when the clutch is engaging. not when the pedal is pressed all the way in, or the car is in gear. I've held the clutch at the point where the sound is and it will keep screeching. (possibly tranny vibrations as the source of harmonic resonance?)

3. the rpm has to be within 1600-2100rpm for it to make the sound. If I rev the engine up high or lower, no sound.

4. the hotter the car, the louder it will be - to a point. so to me it must be related to thermal expansion....

My shop is stumped because every time I've been in, I can't replicate the sound, usually because the car isn't warm enough - though even when it's warm, you have to hit that RPM sweet spot to get it to screech.


One more thing, I had RUF mufflers put on - the sound started some time after that install. I had the Porsche tech's check out the install and they said it looked solid, so it may not be related but it seems a bit too coincidental....

Anyone have a clue what this may be?

 

I hope someone else can chime in. I've got almost the exact problem. Makes an awful screeching sound below 2k.

 

anyone have any ideas?

 

Clutch

 

might be just that the clutch pedal needs lube.
look around some of the forums, especially renntech.

 

Check the throw-out bearing (normal wear item) -- I had a somewhat similar sound (including during clutch engagement) and my indy targeted the throw-out bearing.

Clutch job (using $500 OEM clutch kit from Suncoast: http://www.suncoastparts.com/product..._Code=996Trans) fixed the problem. My '02 C4S did not require dropping the engine, only the transmission.

For $40, also renew the throw-out bearing guide tube (Part #: 996-116-087-01-M100).

While you're in there, you should renew the RMS whether or not there is any leaking ($20 part [use newer updated and improved seal] and maybe 1/2 hour labor) + do the LNE/Flat6 IMS retrofit kit (http://www.lnengineering.com/ims.html) -- again relatively additional minimal labor while transmission is dropped.

Whole set of repairs/upgrades cost me $2,500 (including parts; the flywheel was fine, so I did not need to spend $800 for a new OEM flywheel) and now I'm good to go with the two main 996 concerns (RMS and IMS) taken care of.

I'm also a big fan of the RS engine mounts (see other posts) for getting a solid "one block of metal" feel --$400 set of parts from Suncoast (http://www.suncoastparts.com/product...996performance). My mounts showed some slight normal wear and I did not need to replace, but the RS mounts were a great upgrade for me, meshing well with my PSS9/GT-3 sways/links suspension.

 

To PKStyles: Please check out the video I posted in the thread linked below. Is this the same noise your car was making?
https://www.6speedonline.com/forums/...eck-noise.html

 

hi CMOS,

i just watched the vid, yeah it's the EXACT SAME SOUND! I've been trying to find the root of it for over a year now. some say throwout bearing/bell housing area but i'm not so sure. I had my clutch replaced just over a year ago and the noise started happening 3 months after... which coinides with when i put RUF mufflers on. the guys had to take everything off, headers, cats and mufflers cuz she was ceased up good and they didn't want to break any of it.

My guess would be exhaust. Maybe they didn't tighten or seat it properly when it went back in?

in the colder temperatures its even harder for me to replicate the sound; was gonna go into the shop in a month or so when it warms up AND when my car is warm enough to replicate it for them.

if it is the clutch, i'll be pissed cuz it's brand new, all OEM parts and I broke it in nicely.

random that a 1999 911 C2 and 997 C4S could have the same issue

let me know if you find the culprit before i do; i'll be sure to post the results if/when it does get fixed.

 

could be the Clutch Helper Spring, do a Search

 

well, i got my car back from the shop, drove over 150kms this weekend and haven't heard even an incling of this sound return. FINALLY!!! after almost a year of this annoyance - the love affair with my car is back!

i don't have a definite answer to what the exact cause of the noise is because I had a whole bunch of stuff done, unrelated to the sound. 2 things that could have been a cause according to my mechanic:

clutch dragging - my master clutch cylinder had to be replaced as the pins was smushed and wasn't fully disengaging the clutch.

idler pulleys - replaced all 3, they were ceased to crap and barely rolled, glazing my serpentine belt.


hope that helps. I'd say get your idler pulleys checked first as that's an easy fix and the most suspect as the root of this weird sound.