anyone can tell me what the problem

 

Moved to the correct location.

Anything happen recently to cause this?

 

change clutch 2 week ago

 

uh oh.... knocking. not good, in most cases. GL

 

Does the sound change while the car is under load?

 

doesnt sound like a knock, been there.
sounds like throwout bearing issue or chatter.

 

My guess is something related to tranny more than engine. Does the sound change when you push the clutch in. What clutch and flywheel did you put in and who did the labor. Did you notice any thing on the old clutch and flywheel like the surface was scoured or warped. I am guessing you put in a new throw out bearing, with new clutch and flywheel. The person who did you install do they have experience on installing clutch on 350z/g35

 

if its the throwout bearing what the reason do it.the bearing is brand new

bad installation???

sorry for bad english

 

when my engine is cold it doesnt sound like the video in the first post

yes the sound change when i press the clutch.

south bend clutch and its me who install it (i dont have a lot of experience,its my fisrt time a change clutch)

 

It kind of sounds like chatter to me from installing a lighter flywheel and/or clutch assembly. It's totally normal if that's what it is. Mine sounds like that and it started when I installed new clutch and flywheel.

I am not sure though. I think it might also be or have something to do with the throw out bearing.

 

In the last video (post 9), are you pushing the clutch pedal in and letting it out?

If so, the noise definitely has something to do with the clutch.

If not, it's the AC compressor cycling on and off.

 

I am pretty sure that is a flywheel and you pushing in the clutch gets rid of that "WHIRRING" noise kinda like a cement mixer. I would get a professional opinion but i think that is just flywheel chatter. My stock G35 6mt does that and I have the CD009 tranny. The stock won't be as loud as it is a dual mass flywheel but a lightened flywheel will be easier to hear and more pronounced.

 

Am I the only one that sees: Whats the problem and a shitty cell phone pic?

 

^... Wow

 

sorry but is not shitty phone pic its a video with my iphone4

 

the problem is more the video in the first post (knocking)

 

He prolly just didnt click on it to get the video since there wasnt a "Play" button on it.

FWIW, I have a sound that is similar to yours (not nearly as loud) and I have pretty much written it off as noise from the flywheel. Its pretty common from what Ive read. Not saying this is your issue, though.

 

Try clicking the picture bud

 

that's what my car sounds like when it's really hot outside and i've been driving awhile. i have the jwt clutch and flywheel. the sound will quiet if i press in the clutch.

in the winter is quiet though.

 

My first guess when i heard it was clutch/flywheel chatter as well, especially since there was a clutch change done recently..... if the noise in the first video (under the hood looking at the engine) is whats bothering you and it DOESNT go away when you depress the clutch pedal, it kind of sounds like a loose timing chain... I know it sounds weird but my buddy had this happen to him and had to change his tensioner..... it happened to me on my cbr600 as well, but thats a little bit different lol