My 05 6mt has 15500 miles. From time to time, at idle, i hear like aloose chain rattle noise. I took the car to the dealer a couple of times but they couldnt catch the noise. Rattling sounds like a loose timing chain?
How do I get the service person to believe me? I think a loose timing chain may affect the smoothness of the engine.

Agis A

 

Try pressing clutch and listen.
If timing chain was "loose" it would probably make noise all the time and at all rpm's

 

Hmmmm . . . Consider checking the engine oil level when you hear the rattle. Could it be a valve train noise when you might be low on oil? Just a thought.

 

I found out there is no noise when clutch is depressed?
So is there someting to do ?

 

Nope, that's the throw out bearing. It's normal, mine does it to.

 

has to do with the dual-flywheel i believe

 

It's the trany...!! I was on mynismo.com a.k.a. Performance Nissan. When I was looking at transmission upgrades. When describing lightened flywheels, it said that there would be a chatter at idle. They described it as a cement mixer sound. When they said that, that's what exactly came to mind. It's totally normal. Hope this helps.