2004 Z06 Rattle after engine kill.
Thread Starter
Racer
Joined: Oct 2004
Posts: 376
Likes: 0
From: Huffman TX
2004 Z06 Rattle after engine kill.
I just noticed today, when I shut off my engine and as it is coasting down, I here a rattle...metal to metal sound. It only lasts for a few seconds right before the engine stops. No noise while running. Any ideas.
Thread Starter
Racer
Joined: Oct 2004
Posts: 376
Likes: 0
From: Huffman TX
I did some more investigation today and yes, I heard it from under the car in the clutch area, and pushed it in and turned it off....no noise. I assume this is ok. No warranty issue. You would think the engineers could get the clutch better than this. Sounds like a POS when you shut it off in nuetral. Thanks for the info guys...I love this place.
Le Mans Master
Joined: Mar 2004
Posts: 5,562
Likes: 5
From: South East coast Florida
Originally Posted by vettenuts
Yep, push in the clutch and I bet it goes away. This is covered in the video I believe.
"Marbles in a can" But for some reason they stopped the video in 2004. All we got was this lame DVD showing some of the features of the car 
Advanced
Joined: Aug 2005
Posts: 50
Likes: 7
From: western mass
"You would think the engineers could get the clutch better than this."
The issue may be because of the long input shaft to the rear-mounted transmission. There is gear tooth clearance the gearbox so as the engine coasts to a stop (during which its angular velocity "quivers" with compression pulses), the inertia of the rotating parts causes some torsional flex in the input shaft, which helps make everything rattle in the backlash clearance. An anti-backlash gearbox is certainly possible - or maybe an input shaft with a higher torsional rigidity. Either would add cost for small benefit. Easier to just step on the clutch pedal and isolate the rest of the drive train during coast-down.
The issue may be because of the long input shaft to the rear-mounted transmission. There is gear tooth clearance the gearbox so as the engine coasts to a stop (during which its angular velocity "quivers" with compression pulses), the inertia of the rotating parts causes some torsional flex in the input shaft, which helps make everything rattle in the backlash clearance. An anti-backlash gearbox is certainly possible - or maybe an input shaft with a higher torsional rigidity. Either would add cost for small benefit. Easier to just step on the clutch pedal and isolate the rest of the drive train during coast-down.
Last edited by RB01C5; Apr 28, 2006 at 09:02 AM.
