I have now had this problem with my clutch which has failed once. The TOB has been replaced 3 times along with one new clutch and flywheel, but the problem returns around 500 miles of driving. I drove for about 12K miles on the "bad TOB problem" before my clutch completely gave out. Now, after a clutch repair, the same TOB noise has come back again around 500 miles. No one seems to have a solution to this. The car continues to drive well even with the noise, but I know what ends up happening. Don't know if something from the transmission is binding up the clutch, which may be why changing the tranny fluid seemed to work for some (at least temporarily). I don't understand why this is such a mysterious problem to fix. What's making the TOB go bad every time?

 

It might be the fork. They've updated the fork and this might solve your problem. See below.

Post 16 in this thread.

 

Thanks for the thread info. But I have a 2002 early build 996 (build date Oct 2001). Would this still apply, since that post talks about pre-Apr 2000 Carreras?

 

Hi All... HELP.

Have been all over this forum of late trying to track down my own teapot-sounding whistle, and figured I wouldn't litter the board with another thread since I have a sneaky suspicion this is an AOS issue or resolved with certain of the suggestions above. The sound doesn't fit though, thus this post... have added (I hope) a somewhat dizzying vid that covers it at its worst, as I hovered across the rear. Sound is coming (it seems) from the left side of the engine. At the very end, right after I shut the engine off, you'll hear the noise rise to a crescendo then suddenly stop. Odd.

It’s a 1999 996 C2 Cab with about 103k, and not been serviced since 75k (don't ask). Oil level was very low of late, but back to normal with a quart and a half topped. Clutch (and throwout bearing) done 20k ago. No issues shifting, tranny SEEMS normal. Tran fluid, however, is a wee bit overdue for a change (understatement, yes). No leaks I can see. I did do the little vacuum test... pulled the oil filler cap off and felt the suction. I'd put it on a level of a dustbuster... definitely something noticeable. Engine started to sputter quite a bit and nearly cut out after a few seconds until I quickly recapped it.

From cold, the noise is faint if nonexistent for about 10 minutes of driving, then frequently off and on once the engine temp hits about 200 (??-- roughly between the 8 and the 0 of the 180 on the guage-- could never read that right, but normal I'd say). Oil pressure hangs around 5 for that time, then settles in after regular driving (20-70 mph on my commute home) at around 3-3.5. Once the noise starts kicking in every 30 seconds or so, the oil warning light pops on and off... can make both the noise and the light cut out with a punch on the gas, but it's temporary. Damn thing is LOUD at times. Started a few days ago.

Sooo... am I in for an AOS job? (Rough cost?)Is the tranny fluid swap worth it first? Should I not park this near small children?

(Edited to add: can't figure out how to get the HTML going and embed the vid, but here's a youtube link: http://www.youtube.com/watch?v=T-HRgzinLEo )

<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/T-HRgzinLEo&hl=en_US&fs=1&color1=0x2b405b&color2=0x6b8ab6"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/T-HRgzinLEo&hl=en_US&fs=1&color1=0x2b405b&color2=0x6b8ab6" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>

 

A colleague at work thought it could relate to a sealed bearing somewhere?

 

Geebus that sounds terrifying!

I honestly would start with the serpentine belt off for 10 seconds to verify that it's not a pulley or tension pulley. Then go from there Also try to get under the car to hear it... Front to back difference in sound. But what ever is going out sounds like its going to go with a bang.

 

Sounds ominous, doesn't it? I particularly like the crescendo when you turn the car off... my first instinct is to throw myself behind solid objects for safety.

Oil pressure WAY low now. Ugh.