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 can only infer from the existing connected maintenance records. If the records show continuity and adhere to the recommended maintenance schedule, we will assign a high credit score; if there are gaps of tens of thousands of kilometers, we will assume it was not well maintained during that period and alert you.

Do not use a high-pressure water gun directly! The high-pressure water can instantly damage the fragile aluminum fins of the condenser, leading to a permanent decrease in cooling efficiency. We can only use a low-pressure air gun or a soft brush for surface cleaning.