archfarseer

Hi guys,

I'm relatively new to this forum, and I just got my CPO'ed 2007 manual 997.1tt in January with 25k miles. I experienced something yesterday that worries me, and I wanted to ask for your expertise in this. I will try to explain the problem as best as I could. Last night was the first time I decided to run my car hard after having it for 2.5 months and driving 1000 miles.

1) First time experiencing this issue:
--Stop light, sport mode on, PSM off. (update: replicated the problem. PSM on/off makes no difference)
--Took off after dropping clutch at 2500 rpms in 1st. Car takes off great.
--I engage clutch, shift to 2nd at 6500 rpms (perhaps I should have shifted earlier)
--Disengage clutch. The rpms flicker back and forth (6000-8000ish). Car loses power, but it feels differently from redline and engine shut off because I know how that lunge forward feels like. This was like the car had less power, not shutdown
--I shift to 3rd immediately, thinking lower rpms would help. It does not help. The same rpm flicker happens

2) 2nd time experiencing:
--in 2nd gear at 50mph, sport mode on, psm off
--full gas to 6500rpms, engage clutch and shift to 3rd
--disengage clutch, rpm flicker between 6000-8000rpms. car loses full thrust
--I thus immediately shift to 4th. Rpm flicker continues
--Shift to 5th, same rpm flicker at high rpms

3) The issue doesn't happen at shifting at 6000 rpms, only higher rpms like 6500+
--I shift at 6000rpms, with sport mode on and then off. Shifts perfectly
--I do the same but with PSM off. Still works just fine
--I try to shift at 6500rpms to replicate, but car engages next gear just as well
---I push car to redline and then engine cut off, and then I shift. No problem here as well

Questions)
--what could be going on here? If it's clutch slippage, then why isn't it replicating every time?
--Or is it something to do with engine shut off or rev limiter?
--Any help would be greatly appreciated! Thank you

Will

Igooz

Sounds like you need a clutch...don't sweat it!
It has nothing to do with psm on/off or sport mode...

archfarseer

Man, I would hope not just yet. I bought this CPO only 1,000 miles ago, meaning it should have 50%+ clutch life left as part of the CPO guarantee

Igooz

^sorry...I hope that I am wrong!
(But if I am right, one hard launch should not toast your clutch...maybe the dealer has some skin in this too...)

limitedslip

Found your problem

jonoz

I am not a Turbo mechanic....but....I have the same model and I would never
1.drop the clutch at 2500.....I would never drop the clutch ever.
2. I wonder whether you are over revving the engine....the rev limiter does not prevent over revs. There is a good discussion about this in Excellence magazine. You obviously need your car checked by a Porsche specialist immediately and have your car's over rev history interrogated.
Good luck.

phillipj

Yeah I have to agree. You don't "dump" the clutches in these cars. They were never meant for that.

What you are experiencing is clutch slippage..Shouldn't be slipping with 25k miles unless the clutch has been mistreated..

I would go see your dealer and DO NOT tell him you dumped the clutch at 2500 RPM..

JBurer

Will,
What you're calling RPM flicker is normally an ignition-related item. I had something similar happen on an earlier turbo - turned out to be the voltage regulator.
I'd see what I could get off the ECU's when this is happening. Buy a cheap OBD2 reader and see if you have any codes stored. If you can duplicate the RPM flicker watch the voltage readout and see if you see it spiking.
Best,
John