Vibration between 1100 and 1500 rpm??

[PKRWUD]

Well, that's where you're confusing me. Unless you're driving a diesel, when you turn the ignition off, the engine stops running. If the engine stopped, but the car was rolling, and the vibration was still there, then it can't be engine related. That leaves the rolling chassis, up to and including the driveshaft and transmission output shaft. You also said the vibration occurs when parked. The problem is that when you are parked, the rolling chassis, up to and including the driveshaft and the transmission output shaft, are not moving, and couldn't be a cause.

This is where it becomes a paradox. What am I misunderstanding?

Take care,
-Chris