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wow. blast from the past. mine turned out to be a glazed flywheel. I cured the problem by letting the clutch out gently, barely touching the gas each time I started from a standstill. keep RPM under 1200 until the clutch is fully released. over a few months, the noise slowly went away. I think it helped spread the clutch material more evenly over the flywheel. aggressive starts didn't help. be gentle with it! good luck.
Fixed! finally got this taken care of. my post from 6speedonline for those of you chasing this problem: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
I would assume the release arm had been updated at some point; my car has a reman engine in it (replaced under warranty). The shop that did my clutch is pretty good, they're the LN bearing guys in town here and should be familiar with the short falls of these cars, they should have checked it out for sure. I'll call them and see what they say. Thanks! Patrick
no they didn't check the clutch release arm yet, since the noise has been happening. is that an easy fix?
fair enough although like you said, it hasn't been confirmed by a mechanic so this is all here-say. someone needs to get in front of a porsche tech and make the sound for them and say it's the TO bearing. i'm not fully convinced. my whole clutch kit is brand new, it can't be the TO bearing. i heard it could possibly be a worn tranny mount....
any one solved this? the sound is still present, i almost have to "try" to make the sound by engaging the clutch in a specific way when the car is really warm. i can't replicate the sound often enough to stop by the shop to "show and tell". seems like we have a couple people that have had this problem but no one has posted the cause and or solution. ideas?
sounds like i have almost the same problem. my thread is here: did you find out what it is?
the clutch was changed with the a SACHS clutch kit (a new throw-out bearing is in that kit) in janurary. this "noise" didn't crop up till over 3000kms on the new clutch kit..... weeks after my exhaust install. clutch feels perfect, it just came back from a Porsche certifed MAJOR 96,000kms service including a test drive from the tech. everything is normal, the sound can't be replicated unless the car is very warm.
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 recently 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? My car is a 1999 C2 996
well finally the mystery has been solved, albiet not cheap. 2 of the crankshaft sensor teeth were bent on the fly wheel!!! the teeth are pretty **** thick and there's really no way they could have been damaged during shipping; the box was is good condition when it arrived and i didn't open it before handing it over for install. so that leaves two possibilities, the shop installing it either dropped it or bent them during install. the other... it was bent from the manufactuer and packaged without inspection. the latter is much less likely. so now i'm going to send photos to LUK to see if they will confirm if this is a "manufacturing defect". if it isn't (which i don't think it is, you can see blunt impact on the bent teeth), I'm going after the shop that installed it - as they should pay for the costs having to buy a 2nd flywheel and the hours of labour to swap it out. there is a silver lining to all of this... my IMS bearing has NO PLAY!!! wooooooo hoooooo!! they also removed the dust cover on it so she'll get lube :) on top of that, they ran the serial number on my engine and it's a reman engine!! they can't nail down the milage of it but based on the sparkplugs there looks to be about 40-50k kilometers on it. double SWEET! so all in all the now car drives better than i could have imagined! does any one have any recommendations on how i should deal with getting compensation for this mess from the first shop?
quick update: we're out of options... have to drop the transmission to check the flywheel. most likely put a new one in from the shop and deal with gripforce separately if it is defective. on the plus side, they're going to check the flange and IMS bearing... which the last shop never even mentioned - so there could be a silver lining to this all. and expensive silver lining, but one none the less :)
spoke to the shop, they tweaked a few things on my car that i didn't even notice, such as play in the throttle, clutch pedal sensor (for starting the car) and cleaned up some gunk by the throttle body; smoothing out the idle. these guys seems to know the 996 much better than the last shop. (even though the last shop is porsche certified) as for the P0336 code: they retested the wiring, it seems to be in working order. they put a new crankshaft sensor on the car (one that has been confirmed to be working) and the waveform improves, but still draws the code. they inspected the flywheel teeth with the sensor removed, can't see any obvious damage or flaws. the car is staying the night and they will resume a few more tests in the morning and that the problem is so weird, the don't want to drop the transmission just yet. though they did say, this could be the one in a million shot of a defective fly wheel magnet or equivalent. any ideas i could forward to the guys in the morning to check?
small update: I spoke to LUK tech support on the phone, they said the chances of the flywheel being defective is very very small. The only other two possibilities are damage during shipping or damage during installation - both of which are possible but not probable. So I'm taking the car to another specialist shop for a 2nd opinion. The new shop confirmed that code is an "open circuit code" as Loren pointed out here - and to him, points to an electrical fault, not mechanical. Lets pray it's just wiring or the sensor! Will update again when I have more news. Thanks for the help so far :)
i asked if they checked the wiring, they said yes - then proceeded to fit a new sensor on it. even with the new sensor it triggered the same code. so must it be wiring or the flywheel? also, could the flywheel have been damaged during shipping? it only came in the yellow LUK box, no additional padding....
hmmmmmmmmmmm... well they said they checked the wiring and also put a new sensor on it - only to draw the same code. so is it the flywheel? maybe it was banged during install?