Hi guys,

I tried to search around but couldn't find any post with similar problem. Hopefully someone can help me here.

So, I have a 07 g35 coupe 6mt with 70k miles on it. Aside from pinging noise in low rpm (2-3k) and clutch squeak ( as countless other g35 owners are going though), I have started to hear another noise thats robbing me of my sleep.

Its in high RPM range (5-7k) and under hard acceleration. I have heard it only few times and its hard to find a pattern. Other times, the engine accelerates smoothly throughout. And other than that, there is no other abnormal engine noise.

The high rpm noise is not always there. I can't really say what it is (maybe like scratching noise) but there is no loss of power or anything. And if I let go of gas, the noise stops even though the rpms are still in that range. But if I press gas again, the noise would come again. But its not a constant noise and only happens for a bit like couple of second and stop even if I continue accelerating. I was thinking that it could be pinging but it sounds different from the ping all other are hearing. You can hear the low rpm pinging here: https://g35driver.com/forums/engine-...mt-noises.html

The noise I am talking is - I would say it more high pitched and with higher frequency. Would pinging noise increase in frequency because of high rpm?

What do you guys think it could be? Whats the worse it could be? Pls. help, I bitting my fingers off as I am out of warranty now.

And if my engine was damaged or abused (i.e. run on low oil), is it possible for it to make noise only sometime and be perfect other times? I mean how would engine sound if it was ever damaged because of low oil or redlining? I have never done either but don't know about the previous owner.

Please guys, help is greatly appreciated.