Only a professional stucco inspector will truly be able to tell if you have a stucco related problem. Professional home inspectors focusing on stucco know what to look for and where to look for it.
Here is an overview of what they may do:
An inspector will first walk completely around your home and look for tell-tale signs of moisture - mostly staining, cracks, improper flashing, and stucco running below grade.
A method to identify the amount of moisture in particular areas involves drilling small holes and inserting a moisture probe into the area. The probe holes are then filled with a silicone caulk that ideally matches the color of the stucco and generally blend into the system.