I'm at about 8000 miles and I barely noticed it after the recent oil change. (I think)
Whenever I accelerate pretty hard, I can hear metal grinding... I can't really explain it but it is definitely coming from the engine. I pulled the car over and checked the oil and it was fine. (In the middle range)

Anyone know what's going on? Should I be worried?

 

yes

 

everytime u hear something that isnt usual, go get it checked.

 

it might be this:

 

I hear that noise almost everytime I accelerate hard too! My G has close to 3000km. I always think to myself if this is normal or not

 

At least I'm not alone.

It's kinda hard for me to get it checked out because the dealer is about 60 miles away... unless I can goto the Nissan dealership.

The car feels the same though...

 

It seems more likely that on hard acceleration you would not hear as much from anything inside the engine as you would the exhaust and/or intake noises, etc. I once had a string of popping noises from my car on acceleration and upon inspection by the shop it was found the head gasket was faulty and escaping exhaust gases were what made the noises.

 

why guessing when you can have dealer check it out for free

 

It's far.
I'll check it out next time I'm close to the dealer.

 

road trip!

 

Yeah, I'm getting weird engine noises too but it not only when accelerating, but very noticable when idling. It's a fast ticking noise and doesn't happen all the time so it's hard to bring it in when there's a good chance it may not happen at the dealership and I've just wasted my time.

 

cnugs, those are your hydraulic lifters. it's probably noisiest when the engine is cold and the oil has not pressurized them.

i've found that nissans always have noisy lifters.

and it's perfectly normal...

 

Thanks Altersys. Does yours sound like this too? It didn't start happening until about 1000 miles ago (i have 15000 miles on the car) and I have two friends with G35S and they don't have the same problem, granted one of them has only had it for 2 or 3 weeks now.

 

mine does it for five to ten seconds (depending on ambient temp) when cold starting, then it goes away. this is because the oil pressurizes the lifters.

you may want to try a different oil.

how often do you do your changes? what oil do you use?

a really good synthetic can help with this, particularly at the temperature extremes. do you notice a pattern with respect to ambient and engine temp?

 

The noises seem to be random and not just when cold.
I could have driven 50 miles then start to hear the noise. After maybe 5-10 minutes it goes away. Sometimes it doesn't.