I had a similar noise, around 30mph (have 26000 miles now), only when cold, and just found the answer I think, it is normal for mine. See if this is what you have. Thank you so much to jeepwk2 website.
Electronic Stability Control (ESC) Clicking Noise
The driver may notice a clicking sound coming from the front or underneath the vehicle. This occurs when the vehicle is traveling above 35 mph and during the first portion of a drive cycle. The ESC system will run a calibration routine and if the driver lifts off of the gas pedal, the ESC system will stop the test because the drive may need to brake. The clicking sound is the valves in the ESC system. Once the calibration routine is successful, the noise will not return until the next ignition cycle. Once the ESC system has learned 50 times, the calibration will not be run during every ignition cycle. The sound may also become less noticeable over time. This sound is normal and no service needs to be done. -------------------