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).

Yes. Third-party service providers in logistics, inspection, customs clearance, and finance can join the platform as "service providers."

Absolutely not. Any secondary damage caused by overseas non-professional repairs, violent disassembly, or the use of inferior replacement fluids will immediately void any form of "extended parts compensation" we provide.