My 2005 Infiniti G35 has 144,000 miles, two new rear tires and two good front tires. Sometimes, and I cannot nail down or reproduce-on-demand this situation, my car will suddenly begin to vibrate as if I’m driving over a smaller version of those rumble strips on the side of the road. The vibration continues when I take my foot off the accelerator, and will continue at a slower rate as I decelerate until I stop. Often it seems that when I come to a dead stop and accelerate again, the vibration stops, but other times it will continue as I accelerate.
But what’s really odd is other times I’ll just be cruising along and the vibration will begin, keep vibrating for a few miles, then peter out and disappear. I haven’t totally nailed down whether or not braking affects it, but if pressed I would say that I would use the brakes at least once before it disappears. Also, it only seems to begin once I hit 50-60 mph, but again, it doesn’t happen every time I go this speed. Other times this car drives incredible and makes the road feel as smooth as glass.
I haven’t taken it to the shop because I’m sure they won’t be able to reproduce it, so I’m hoping there’s someone out here that has some ideas. Thanks all!