I am having a 04 Coupe
Recently I discover that the engine may produce some noise that never happened be4.
The noise only exist randomly, but the frequency is currently increasing
The rpm of the engine didn't go up, but an additional noise comes out at a sudden, the noise like something is accelerating with a higher peak of voice than an original quite VQ35DE engine.
However, i didn't spot anything wrong with my engine tho.

Wut's the problem is going on with my engine, it's made me feel bad when i am driving it

 

Check ur oil. The bearings are known to go bad in some G's. Check for metal shavings in the oil...

 

You're going to have to make a sound clip of this noise that you speak of. Your English is a little rough(don't take that as an insult or anything... I just presume you are of foreign descent), and your description of the noise isn't precise or descriptive enough for people on the internet to narrow the cause of the noise down much at all.

 

well, it doesn't work i guess, because the noise is slightly higher peak than the regular engine sound...u won't listen it clearly by the computer speaker. it's reallly difficult to explain by english i understood.
so frustrated by the noise

 

Unfortunately these kind of things are really hard to deal with on the internet. If you're worried about it take it to a competent mechanic.