Mr.Magneto

2016 Cayman, base; 22K miles, 6-Sp., never a problem.

Car stopped, in neutral, clutch out.
Lightly giving gas metallic tapping sound becomes audible at 1800RPM and increases with RPM; tapping a lot but seems inconsistent in rhythm.

Car stopped, in gear, clutch in.
No sound at all.

I've poured over the shop manual trying to find some part that would "hit" some other rotating piece.
Throw out bearing? Pilot bearing?
I have a date with the Dealer to pull the transmission, but my confidence level with these very nice folks isn't so high..

Thoughts?

Thanks in advance!!

sghokie

Reminds me sort of a mercedes c320 I used to have. 6 sp manual transmission. It would make a tapping noise when I would have the clutch out while stopped at a light or something. I couldn't really hear it when driving.
I took it to a place to have the clutch changed out, but it still made the same noise when I got it back. I took it to the dealer and they said it needed a new transmission, I declined, but when I got it back it didn't make that noise any longer.

Mr.Magneto

Interesting that that all turns out! LOL!

I was told today that a new trans is no issue but I'm not sold on it being a really major problem.
The may have to pull the transmission but the issue (I think) is living in the clutch/PP area - just searching for other experiences..

Thank you!

sghokie

In your case with clutch engaged but not in gear the only thing turning against something not turning is the input shaft in the transmission.
I kind of doubt a pilot bearing would make noise in that case, because the flywheel, clutch, and input shaft are all turning a the same speed.
I would think if a throwout bearing was the problem causing a tapping noise it would happen while in gear too as the throwout bearing is only doing anything when you press the clutch.
Another possibility would be a Dual Mass Flywheel. If the springs are loose I suppose it might cause that problem.

(Not an expert, but I have replaced a clutch a few months ago in a 986)

ChicagoSpeed996

Mr.Magneto

Hi and thanks to all who have posted insights..
I was going to make a recording of the sound but the engine revving almost covers the ticking/knocking sound - so I didn't..
Goes in to the PCar-Folks next Monday..

Many thanks!

ChicagoSpeed996

Mr.Magneto

Dual mass flywheel, they say...
The entire assembly is out of the car..
This been an issue in the past?

Jim137a

Mr.Magneto

That post describes it exactly... We'll see how it plays out..

Thank you for the post to the link!

Dave in Chicago

The dual-mass flywheel is quite heavy, but serves a purpose. When you swap them out for lightweight single-mass flywheel on the 968 race cars, you're greeted with a distinct sound around 1800-2200 rpm that sounds like a bucket of bolts being rattled around. I believe it's the 5th gear set rattling on it's shaft in the G50 6-speed. Causes no harm, but it's a striking and very unpleasant sound in a street car. Good luck!

Mr.Magneto

This, indeed, turned out to be a dual-mass flywheel failure..
Trans out, new FW and related component, back together, and all is good..

Thanks for the feedback!