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).

Once the car system (especially in a closed ecosystem) undergoes a major version upgrade, its bootloader is usually locked, preventing downgrades. If this happens, there is basically no solution in an overseas environment. Therefore, we strongly warn: do not blindly insert a USB drive to upgrade while offline.

It's extremely difficult. The security level of Chinese brand immobilizers is very high, and you must connect a specialized factory computer to the vehicle's OBD and be online with the domestic server to match it. Losing all keys usually means you need to replace the entire lock cylinder and anti-theft control module while overseas.