Why does the clutch stop half way on 'brisk' launches? PSM?

Hi - just got my Cayman S but was wondering why the clutch pedal seems to have a mind of its own on brisk launches. It sticks half way for a few seconds then releases. I assume its the traction control.... Thoughts? :burnout:

That is not normal.

Get it checked out, I've been doing alot of brisk launches of late & never experienced this.

Hmm so it doesn't happen to you guys.... Yes it is a little strange and it may be that something is a miss...but it feels very 'deliberate' though like the car is doing something and outside of this the car is fine and the clutch works as normal. I might talk to one of the Porsche Driving Instructors and see if this is the PSM / ASM doing its thing...and try it with PSM off and see if it happens again...

Maybe this is an issue of wording? PSM will cut the throttle if wheel spin is detected. It feels like fuel starvation. The gas pedal may remain flat on the floor but, but you will feel a complete cut of power until traction is regained. BTW, the PSM light in the instrument cluster will flicker when it is actually operating. To the best of my knowledge, PSM has absolutely no interaction with the clutch. Brian

some hyd. clutches will hang up on a "drag strip launch" if fluid is old and/or system is very hot,presure plate going over center...either way its not right ..is this the only time it hangs up...mileage....rpm wise ???

I agree with everyone else here, this doesn't sound right. Is your car a 2007 or early 2008? There was an issues with the clutch pressure plate bolts not being torqued down properly causing many owners grief when the clutch just fell to the floor. Porsche issued a TSB on this. Do a search on here for all the details. But, get it to a dealer ASAP. Good luck.

It sounds very similar to what I have experienced in the past - a couple of times with the Cayman, and in various other cars, but it is the exception, rather than the rule, and just because it has happened, doesn't seem to affect the clutch subsequently. When I've experienced it, it's primarily due to excessive slippage, ie. getting the revs up to high for the amount of clutch engagement, or conversely, letting out the clutch too slow in overanticipation of bogging the revs. This is always experienced 'mid' engagement. I've always conjectured that because of excessive slippage the clutch plates aren't locking up, gasification between the plates occurs (similar to brake pads against brake rotors) and that keeps the plates from fulling engaging - until slippage goes down below some point. This can be felt as the clutch pedal 'pausing' - you can feel it as a distinct lessening of resistance against your foot. A big sign to get out of the gas and let is hook. Anyway - I'm proposing there is nothing wrong as long as you don't keep doing this repeatedly and any specific instance doesn't fry the plates or warp something - and that hasn't occurred to me in the past (been driving standards for over 30 years and never had to replace a clutch). I won't include the clutch's I've fried in my bikes! (and they don't experience that same clutch pedal 'float'). I've always let the car 'rest' after doing this though as it is not a 'good' feeling. Hope this helps in knowing there is at least one other person out there with similar experience, and nothing bad has come of it (yet!). Just watch your technique - usually due to overaggressiveness on my part.:cheers:

Back in the early days my Cayman S did it many times, and Porsche did a recall and changed the clutch slave cylinder, the old cylinders stroke was to short, and i had to flick the pedal back up with the toe of my shoe but only when pulling away hard all is QK now, car is an 06 if you check back though the forum i came up many times and a lot of cars were changed Bob

The only clutch issue I had which was not really an issue was that the engagement take-up position varied a few times. Apparently its due to the self adjust function as the clutch may wear. Definitely get it checked out.

Thanks guys, I think I will get it checked out. The car is an 09 CS with 500 miles...still breaking it in...and like I say its a brisk launch not a dump and burn type thing as I'm keeping it generally under 4000 RPM....I can't recall the exact RPM I launched at but given its been on a hill it had more of a load than normal...but again its not like 5000+ or anything.... Both times its happened was on a hill start situation...outside of that everything is fine....maybe just wearing in issues??

Hill starts change the answers I would think. Your description of the event almost sounds normal for hill/clutch events. Hate to ask but what is your own experience with manual transmissions and hills?

I seem to remember that the 09's have a new hill holding feature to prevent rollbacks on the start? Maybe this is what is happening. Let me do a search and come back in a bit...

brisk launches on a hill ? you aint doin hill climbing racing are ya

Here we go. I don't have an '09, but maybe this is a behavior of the new hill assist feature or it could be this feature acting up. http://www.planet-9.com/cayman-boxs...n-boxster-complaints/33467-drive-off-assist-failure-gen-2-boxster-may-09-a.html

Just called the dealer...he doesn't think its normal and has asked to bring the car in. I'll keep you posted. Cheers...