VIBRATION around 2000 RPMs
If ok I would suspect torque converter.
Open the hood, make SURE it is in Park (and put the parking brake on). Have someone stand BESIDE the car (not in front of it). Hit the gas and let off quickly. Try at 2000 rpm. See if the engine jumps to one side. If so, it's engine mount.
If not start with the transmission mount. My GL was vibrating exactly at 1800rpm, and replacing the transmission mount fixed it completely. Transmission mount looked brand new when I took it out, and I thought I misdiagnosed. As soon as I drove it after the fix, I noticed the huge improvement and vibration has been gone since!








