Currently have a 2009 g37x sedan with 124k. For a while I have noticed every once in a while as I am driving in 2nd gear and about to speed up, the car vibrates pretty bad. If I hit the throttle hard the car will vibrate change gears and be perfectly fine. It doesn't happen all the time, probably one or twice within a 25 minute drive.

I have noticed it only ever happens when I am in second gear, speeding up to around 30mph (around 1k rpm) I will start to hear a slight vibration that increases as I tap the gas. I will hit the gas a little hard and the vibration will go away as the car changes gear. It changes gear fine with no lag or feeling of it slipping. Makes me think it is something with the transmission. What it also may be is something with my tires. My tires are shot and I am currently waiting for a new set as I am getting them for free. Car really needs to be balanced and alligned so I am hoping that would fix the issue. I fear it is the transmission though. I know this info is very broad so I apperciate any input. I will deal with the dealer after I get my tires as it is hard to isolate the problem as my tires are shot and how the car needs to be aligned and balanced really bad. Thanks. I also have a bad fuel damper that is very loud at idle and whines with the rpms. The bad damper has gotten much worse and I have had the bad damper for about a year.