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).

Supply and demand determine prices. In the Chinese market, mainstream colors like black and white have much higher resale values and market circulation speeds compared to less popular colors (like pink or bright green). Therefore, there is a price difference of thousands of RMB for specific colors at the procurement level.

This is a typical case of "secondary damage caused by unprofessional rescue." Many hybrid vehicles require access to "maintenance mode" via engineering computers to allow the water pump to run at full speed for exhaust. We do not bear any moral or financial responsibility for cylinder damage caused by local technicians' misoperation.