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 FOB or CIF terms, all risks before crossing the ship's rail are borne by the seller (us). For minor scratches, we will provide a price discount based on the damage assessment; for serious damage, we will immediately terminate the vehicle delivery, refund the full amount, or replace it with a vehicle of equivalent configuration.

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.