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).

We will never perform blind deep disassembly unless there are clear severe fault codes or extreme noises. The sealing of the engine and transmission is crucial, and compromising the factory seals to investigate non-existent issues is unprofessional. We rely on data flow and external acoustic and fluid analysis to make judgments.

After receiving the final payment, we will send you the complete set of original customs clearance documents via DHL or FedEx, which typically includes: - Bill of Lading (B/L) - Commercial Invoice - Packing List - Certificate of Origin (CO) - Used Vehicle Export License issued by the Ministry of Commerce of China Note: If your local customs requires additional documents (such as VIN consistency certificate), please inform us in advance before shipping.