I have a 06 g35 sedan 6mt and after the car is warm and been running for a few minutes the valves seem to tick at lower rpm's. >2000. I was wondering if any one else has this issue or it may be another item under the hood that is initiating these sounds. Also I only have 600 miles on the car

 

What kind of gas are you using? If you are not using premium, you should.

 

This is the first tank the dealer filled up for me after purchase, they put 89 in it. Could that be the cause? I have still a half a tank left, so I have never ran 93 in it yet although I anticipated doing so after my free tank was used

 

Those aren't the valve you're hearing, it's the injectors. The VQ injectors are quite loud. Take a long screw driver and place the blade end on the injector housing and put your ear up to the driver handle. You'll clearly hear the injector "tapping" away.