Slight rattling noise when clutch is disengaged at idle, thoughts?

Your flywheel. Without hearing it myself, I can't tell you whether to be concerned or not.
Heck, it's winter there. Go ahead and have a look.

 

My T/O bearing rattles sometimes but doesnt sound like that. You cant diagnose over internet. Even if someone guessed it right you still have to tear it apart. Start there and post some pictures and someone can help you..... it could be serious. so matter what you have to start there. Dont waste time and energy having people try to guess....tear it apart

 

I would agree with flywheel. Probably could use a re-grease if thats never been done. There are so many components to the flywheel system. It could be a broken spring, even your throwout bearing. It takes about 20 minutes to take the clutch assembly off so would be best to just get in there and inspect.

 

flywheel....they all make some noise.
post a sound clip

 

Why? it could be causing damage everytime you start the car.......tear it apart and fix it...enough said

 

Normal.

 

+1

 

I presume that by "engage the clutch" you mean press the clutch pedal (which is actually disengage). If this is correct, slight rattle is quite normal from warmed-up gearboxes - it disappears when you press the clutch. It is also normal to hear brief "clicks" on engine start-up or shut-down. Many of the shafts and gears in the gearbox are still "free-wheeling" when in neutral and engine running and this is what produces the slight rattle. When the clutch is depressed, a number of the gears stop turning and the rattle disappears.

Top quality fully synthetic gearbox oils may eliminate this kind of rattle.

 

he mentioned a loud clack....not the normal rattle

 

"Load" clack.....I didnt read that in his post. The 355 tranny makes all sorts of sounds that sound weird to those that are not used to this car. All he talks about are normal sounds of this cars tranny. Sometimes you hear them more than others. When its hot outside, they are more pronounced. The OP will learn soon enough that the 355 has its small quirks but when maintained properly, it is virtually bullet proof and will give the driver more pleasure than almost any other car on earth. Worrying about every little sound and much of the BS spread about the 355 has caused some much needless lost sleep.

 

The only time I ever heard a clack was when the bypass valve was stuck open, I started the car, and "Whap!!" Mine rattles now, but it sounds more like a sizzle-rattle. I once thought it was the clutch or flywheel, but I can make it stop by touching it with my hand, so then I knew I found my "rattle". Good luck, a mechanics stethoscope helped me find it.

 

and this is why I suggested a sound clip.......the OP said there was a "clack"......likely normal though

 

Mine rattles also..usually after it warms up its gone... I didnt check mine out it had recently had a new clutch put in. I personally wouldnt want to tell you its normal. Either drive it and hope for the best or tear it apart and investigate. At the minimum take to a good Ferrari mechanic and let them give you a pass or fail