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).

It completely falls under force majeure. After the delivery is completed (crossing the ship's rail) under FOB or CIF terms, the seller (us) bears no liability for refunds or compensation due to political risks or legal changes in the destination country that hinder customs clearance or lead to confiscation.

Apply for a certificate of origin from the local customs or trade promotion agency, proving that the country of manufacture is China. This is a necessary document for customs clearance in regions like the Middle East and Southeast Asia.