Automotive Service Technician (310S) Engines Practice Exam

Thermal cleaning uses high heat to burn off organic contaminants, but it can leave carbonized deposits, ash, and oxide scale on the surface. These residues are often hard to remove with heat alone, so a secondary mechanical cleaning like shot blasting helps physically dislodge and remove them, while washing can rinse away fine particulates and cool the part. The other methods rely on liquids or cavitation to loosen contaminants, so they typically don’t require an abrasive post-cleaning step to the same extent.