We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).

To prevent intermittent failures due to aging of the resistance wire, we will start the engine and set the seat heating/ventilation to maximum for at least 5 minutes, confirming significant temperature changes or airflow output in the cushion and backrest using an infrared thermometer or body sensor.

We mainly collaborate with professional organizations certified by China's national CMA (Certification of Inspection and Testing Institutions). If you need the highest level of international endorsement, we can arrange for independent inspection agencies like SGS or TÜV to conduct Pre-Shipment Inspections (PSI) before loading at the port.