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).

Under normal circumstances, it takes 15 to 25 working days. This includes: domestic transfer of ownership (3-5 days), applying for an export license (3-5 days), inland trucking to the port (2-5 days), customs inspection and waiting for loading schedule (5-10 days). Do not trust false promises from other channels claiming 'loading within a week.'

Obtaining precise internal resistance at different SOC levels requires disassembling the battery pack and connecting it to a professional charge-discharge cabinet for several days of cycling tests. This is beyond the scope of non-destructive used car inspections; we only provide real-time estimated internal resistance data based on OBD port readings.