I have a 2015 Chevy suburban LT with a 5.3 4 x 4. I bought it recently the transmission was rebuilt with a new torque converter around 118,000 miles it currently has 122,000 miles on it it has a slight vibration even when the car is in park neutral or in drive between 750 and 800 RPMs I’ve had the plugs and wires changed I have run cleaner through the top end of the engine for the injectors but this little vibration continues do you have any idea what this could be thank you so much!
Presuming no misfire codes, if this vibration started immediately after the rebuild, I would first check the motor and transmission mounts - V8s are not perfectly smooth,but the engine mounts tend to dampen the small vibration - that's why they are rubber or hydraulically cushioned. Any looseness or mount deterioration would allow unusual vibration to reach beyond the engine to the car.
