I didnt have much luck on the myg37 forum with this so Im going to post it here. I am a former g35 owner, but recently switched to a g37 coupe.
I recently picked up an 09 g37 coupe with 120k miles. It has a clean title, and has been serviced by the dealership pretty regularly. I have the service records in hand. The motor seems to have a ticking/knocking sound. I checked the oil level and its full. Ive put 1000 miles on it already and the oil has not moved. Also, the motor seems to shake at idle like its missing or something.. It is very noticeable when In drive, Reverse and Park. However, it goes away slightly when in neutral. The shaking can best be described as when your car is at a red light and feeling like it might stall.. However, the G hasnt stalled on me. Rpms will drop slightly and cause shaking but not to the point of stalling YET.. The ticking motor and the shaking is starting to concern me...
However, the engine runs great. Plenty of Power, gas mileage is good and car is super clean.. I was comfortable buying the G with high mileage because of the service history records.. but now Im thinking I might have bought a lemon..
Here is a video I took today: