rja

Ran into some issues today at the track. It was hot out (for Seattle area) and not sure if a factor. Regardless, 2 issues. Probably not related but hard to know for sure.

1. After a couple 20 min sessions, engine started sounding 'off'. It's hard to describe exactly, but sounds rougher but not missing. Hard to tell if down on power, but not drastically if so. I don't notice the sweet spot coming in around 4500 RPM and up. I thought perhaps bad gas since it started occuring right after adding fuel but I emptied that tank on the way home and fresh fuel makes no difference.

2. Car became progressively more difficult to shift during the session. Definitey heat related. By last session, I only got two laps in before gear shifts were grinding. Off track and in paddock, could not even get into reverse no matter how many attempts until shutting off engine and then it slipped right in. So we think it's hydraulic (slave cylinder) or clutch itself. But clutch is farily new and not slipping. And after the car cools down, system works fine again.

Anybody out there with similar experiences on either front?

Thanks,

-Roland.

ILLCOMM

It's because you were going too fast.

mooty

clutch disk and pp?
three ca rs in nor cal had same issues this last minth

85Gold

^ GT3RS clutch or TO bearing real common problem.

Peter

Ur20v

Agree with Mooty, sounds like clutch.

Get the fault codes pulled. Check your exhaust valves are functioning, if stuck you will loose torque and it will sound different. Also check/clean MAF engine will feel sound flat if it is dirty/faulty.

Jamie_GT3

My vote is pressure plate or throw out bearing. Sorry I missed you!

Engine was off over 4500, could be variocam related? Get it on a Piwis and check actuators etc... Maybe spark plugs as well

P.J.S.

PP

rja

Thanks for the responses. Clutch & Pressure Place were both recently replaced. It was preventative, not because the old ones were abused / worn. Given that the car is fine when cool (or just plain not subject to heat buildup at track) are folks still thinking clutch / pp? We're thinking possibly the slave needs a bleed.

I'm more concerned about why engine running rough. Again, only slightly but definitely off. I just went and checked my telemetry and speed at end of straight remains consistent throughout day (and with previous events) so the car is not down on power (or at least not substantially so).

CRex

Bizarre clutch behavior when hot makes your T/O bearing and PP look suspect. Been there and that was my problem. Hydraulic issues, if any, should be persistent and won't affect you only when hot (unlike the brakes, the clutch fluids do not boil and there won't be gas "bubbles" in the system)

On engine running "different"... can you check your exhaust for object damage / leaks? There are countless causes but the first step always begins with checking the oil filter for debris and looking under the car for plumbing damage.

Just some ideas to help get you off the ground, literally. Good luck.

malmasri

Even if you had them replaced, they can still fail, this was a POS design by Porsche and failed on every car that has been driven the way it was meant to be....make sure you have the 4.0 Clutch disc and PP.

rja

Thanks CRex. Had the car on the lift today at Cantrell's shop. No signs of exhaust leaks. No CELs or codes thrown. Tech agrees w/ me that it doesn't feel like the cams are 'coming in' at 4500 like usual but car otherwise seems fine. Also noticing a 'click' sound when I start the car whenever it sits for more than 5 minutes. I read the thread on the cam timing bolts not getting torqued properly at factory, but symptoms I'm seeing seem much less severe (i.e., no loud rattling, no CELs, etc.).

Jamie_GT3

Might be a better safe than sorry. Low speed harmonics on the 3.8rs can cause can bolts to come loose as well as pressure plates...

rja

I took the car to the track yesterday (Monday) after eliminating some possible causes on Sunday. Cantrell was at the track and available to diagnose the issue. All indicators pointed to the flywheel. The 'clicking' sound I was hearing when I started the car was instantly identifiable to Colin Cantrell as starter. Hmm, rough engine, starter noise, rough engine. All arrows pointed flywheel or pressure plate issue.

The folks at Cantrell were kind enough to give me a tow home and jump on this for me today. Culprit is the pressure plate as can be seen in photo. No damage to any other components except for starter gear which was slightly mangled -- presumably from debris.

Since folks will probably comment, this was not the OE pressure plate. Ironically, I asked for the OE unit to be replaced with a heavier duty Sachs unit during the off season as a preventative measure to provide me with trouble free service this driving season (the OE unit gave me no problems). Three lapping days in, and boom. So needless to say, I'm unhappy about this but relieved nothing major.

Jamie_GT3

Sorry to hear about the PP issues, but glad you got it resolved!

rja

Thx Jamie. Me too.