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).

Always rely on the original factory network data from the 4S store. Third-party platforms may have delays or errors when capturing data (such as incorrect VIN entry). In case of a conflict, we rely on physical verification of the actual vehicle to resolve the data discrepancies.

We will use a megohmmeter (insulation resistance tester) to measure the insulation resistance of the high-voltage bus. If the resistance value is below the national safety standard, it indicates a risk of leakage, and the vehicle will be deemed unqualified.